Ok, I've got a really weird situation, and looking for some advice. This is my daughter's car... 1985 Fiero 2m4 SE 5-Speed.
Here's my problem... coolant temperature gauge, AND the ECM CTS (Coolant Temperature Sensor) are both showing below 100 degrees while I'm driving the car around. It's affecting my fuel consumption as well.
TLDR: About 4 months ago, I was having issues with coolant gushing out of places. Turns out I had a cracked head that would only exert pressure on the cooling system when the car was driving, otherwise at idle, it was fine. The temperature gauge DID in fact read properly at that point.. but only after replacing the coolant temperature sending unit. The new one I'd installed was giving really bad readings, it would creep up to 240+ when the engine was absolutely not running like that. I replaced the sending unit for the gauge, and it was fine.
CURRENT: I swapped out the cyl head, no longer having coolant issues. Car is driving fantastic, but now both the CTS and the Temperature Sending Unit are reading extremely low temperatures. I've got Paul Romsky's ALDL reader, and it's showing that my car has a CTS of around 50-90 degrees Fahrenheit... and it slowly creeps down and creeps up, but stays in that range. It does this continuously and never gets above 100 degrees. Oddly enough, my actual temperature gauge (which was tested by Jack Gunsett (and working before) refuses to show anything above 100 degrees. When I turn the car on, it literally sits at 100 degrees and stays there, never moves.
I have a 185 degree thermostat in it, and I know coolant is fine. I'm not losing any coolant, and I know it's getting up to operating temperature as I use my laser temperature gauge and the head is around 205-210 degrees, and the temperature at the coolant neck before the thermostat is around 195, and ~180 after it.
Another odd thing is that the radiator fan is always on. It's never not been on. I've been meaning to check the relay, but just haven't gotten around to it.
The car has perfect uncrushed cooling tubes, a brand new 3-core radiator that's oversized, the best water pump design out of like 4 of them, and 50/50 antifreeze mix with Water Wetter additive. Obviously, it's running extremely efficiently... but with it being 70 degrees outside, I know the engine isn't running at 54 degrees.
Not even sure where to check. Everything about the car is great... but with the CTS thinking I'm driving in a snowstorm, it's getting pretty poor fuel economy. How do I even begin? There are no other issues...
Ok, I've got a really weird situation, and looking for some advice. This is my daughter's car... 1985 Fiero 2m4 SE 5-Speed.
Here's my problem... coolant temperature gauge, AND the ECM CTS (Coolant Temperature Sensor) are both showing below 100 degrees while I'm driving the car around. It's affecting my fuel consumption as well.
TLDR: About 4 months ago, I was having issues with coolant gushing out of places. Turns out I had a cracked head that would only exert pressure on the cooling system when the car was driving, otherwise at idle, it was fine. The temperature gauge DID in fact read properly at that point.. but only after replacing the coolant temperature sending unit. The new one I'd installed was giving really bad readings, it would creep up to 240+ when the engine was absolutely not running like that. I replaced the sending unit for the gauge, and it was fine.
CURRENT: I swapped out the cyl head, no longer having coolant issues. Car is driving fantastic, but now both the CTS and the Temperature Sending Unit are reading extremely low temperatures. I've got Paul Romsky's ALDL reader, and it's showing that my car has a CTS of around 50-90 degrees Fahrenheit... and it slowly creeps down and creeps up, but stays in that range. It does this continuously and never gets above 100 degrees. Oddly enough, my actual temperature gauge (which was tested by Jack Gunsett (and working before) refuses to show anything above 100 degrees. When I turn the car on, it literally sits at 100 degrees and stays there, never moves.
I have a 185 degree thermostat in it, and I know coolant is fine. I'm not losing any coolant, and I know it's getting up to operating temperature as I use my laser temperature gauge and the head is around 205-210 degrees, and the temperature at the coolant neck before the thermostat is around 195, and ~180 after it.
Another odd thing is that the radiator fan is always on. It's never not been on. I've been meaning to check the relay, but just haven't gotten around to it.
The car has perfect uncrushed cooling tubes, a brand new 3-core radiator that's oversized, the best water pump design out of like 4 of them, and 50/50 antifreeze mix with Water Wetter additive. Obviously, it's running extremely efficiently... but with it being 70 degrees outside, I know the engine isn't running at 54 degrees.
Not even sure where to check. Everything about the car is great... but with the CTS thinking I'm driving in a snowstorm, it's getting pretty poor fuel economy. How do I even begin? There are no other issues...
Thanks!
radiator fan on at all times huh? did you pinch wires or you got a short you can trace? or did you accidentally cover too many threads in thread sealer if it aint those then maybe its bad sensors again? new stuff is garbage right now
I've got Paul Romsky's ALDL reader, and it's showing that my car has a CTS of around 50-90 degrees Fahrenheit... and it slowly creeps down and creeps up, but stays in that range. It does this continuously and never gets above 100 degrees.
Any chance those temperatures are actually in Celsius?
radiator fan on at all times huh? did you pinch wires or you got a short you can trace? or did you accidentally cover too many threads in thread sealer if it aint those then maybe its bad sensors again? new stuff is garbage right now
That was actually an issue that existed when I got the car. I should take a look at the wiring in the service manual. As long as the wiring isn't shared somehow with the other sensors, then my guess is it's probably a relay or something. I'll probably try to solve these one at a time. The fan runs regardless of whether or not I disconnect the fan switch sensor. So, it might be an HVAC wiring issue since I know that's related.
I should probably try to solve these one by one, I guess I assumed that they might somehow share some wiring or be related.
quote
Originally posted by Vintage-Nut:
Did you test the Coolant Temperature Sensor?
{Oversized 3-Core Radiator / 185-Degree Thermostat / Radiator Fan is Always ON and the Coolant Temperature is Too Cold}
It sounds like that the coolant system was designed for the desert.
With an extremely efficient coolant system with a small engine, the coolant flow might be the problem; not the sensor.....
Did you unplug the radiator fan to see if the coolant temperature will raise? {Of course, fix the circuit}
Did you try a standard 195-degree thermostat? {Easy to Change}
I don't remember if it was an issue before we started to tear down the car. But if you saw my other posts from a while back, we had a cyl head issue after rebuilding the engine (the cyl head had a crack in it). But the brand new sending unit sensor was actually bad. We replaced it, and then it started working.
Now, the temperature gauge is stuck at 100 degrees and doesn't move at all from there. I may try to wire up manually my spare set of 85 gauges to it directly to the sensor.
And yes, haha... I know how to change a thermostat. We just rebuilt the entire engine. Come on man, you know me... I've been on here for 25 years.
Do you know if these sensors share any common wiring... other than maybe the ground?
quote
Originally posted by Patrick:
Any chance those temperatures are actually in Celsius?
Well, I know my gauge cluster isn't in celcius, and it doesn't move. But it's possible I have three completely separate unrelated problems that are all related to temperature. You know... it's seriously unlikely, but anything is possible. I did use the laser temperature reader, and it's reading normal healthy engine temperatures. I'm using Paul Romsky's ALDL scanner... but the CTS says Fahrenheit.
quote
Originally posted by Mickey_Moose:
Test the wiring from the gauge to the sensor - ground out the wire at the sensor - does it affect the gauge/ALDL software?
If it does, you can eliminate the wiring...
Ok, I'll check that this weekend, thank you!
quote
Originally posted by GodSend:
Measuring in beaver pelts instead of eagle feathers is a common mistake...
And yes, haha... I know how to change a thermostat. We just rebuilt the entire engine. Come on man, you know me... I've been on here for 25 years.
Todd, please reread my post...
When I said if you tried a standard 195-degree thermostat; this means "remove the 185-Degree Thermostat and try standard 195-degree thermostat indeed."
hm yeah sounds like you got a hvac wiring issue if you can disconnect the fan switch at the engine unless there is a short to ground somewhere like mine was honestly i would ohm out your temp sensor and see what happens
When I said if you tried a standard 195-degree thermostat; this means "remove the 185-Degree Thermostat and try standard 195-degree thermostat indeed."
Good luck with your issue...
I guess I’m not seeing how 10 degrees of difference in a thermostat can make up for ~90 degrees of temperature. I have both a new 195 and new 185. Are you saying you think the thermostat is bad? Or are you telling me 10 degrees would make a difference?
The engine was designed for a 180 degrees. 195 degrees was mandated in 1978 to improve catalytic converter efficiency… that’s the only reason why I use a 180 because the engine will be healthier long term.
looking for some advice / ALDL reader...showing...CTS...never gets above 100 degrees. / actual temperature gauge (which was tested by Jack Gunsett (and working before) refuses to show anything above 100 degrees. / Not even sure where to check
My suggestion was "coolant flow" might be the issue, especially with a 'stuck' radiator fan always ON.
However, apparently you won't accept 'that' suggestion...
IF you're really "looking for some advice"
"Unplug the radiator fan" first by removing the coolant fan relay - CHECK if the coolant temperature will raise. "Fix the circuit" - CHECK the coolant fan relay first, if good, CHECK the A/C High Pressure Cut-Off Switch {my shorted years ago} Lastly, "try a standard 195-degree thermostat"
Have Fun, VN
------------------ Original Owner of a Silver '88 GT Under 'Production Refurbishment' @ 136k Miles
As has been suggested, check the resistance from the contact on the sensors to the base of the sensor, when cold, and as the engine comes up to temperature.
Record.the results of the resistance readings and temp measurements with the heat gun.
Let us know the results.
As far as electrical issues, check the connections at the gages on the flexible circuit board, the instrument cluster plugs, the C500, and the sensors.
My suggestion was "coolant flow" might be the issue, especially with a 'stuck' radiator fan always ON.
However, apparently you won't accept 'that' suggestion...
IF you're really "looking for some advice"
"Unplug the radiator fan" first by removing the coolant fan relay - CHECK if the coolant temperature will raise. "Fix the circuit" - CHECK the coolant fan relay first, if good, CHECK the A/C High Pressure Cut-Off Switch {my shorted years ago} Lastly, "try a standard 195-degree thermostat"
Have Fun, VN
No, the temperature gauge doesn't change at all... stuck at 100. The actual temperature on the block does change (when measuring it with a laser reader).
I'm thinking possibly a wiring problem... or a combination of that, and bad sensors. It's entirely possible that I have a problem with each temperature sensor on the head, at the same time, with different issues.
I'll check the A/C high pressure switch. I replaced it with a new one since I'm going with a V5 compressor rather than the older one.
Originally posted by 82-T/A [At Work]: I guess I’m not seeing how 10 degrees of difference in a thermostat can make up for ~90 degrees of temperature. I have both a new 195 and new 185. Are you saying you think the thermostat is bad? Or are you telling me 10 degrees would make a difference?
The engine was designed for a 180 degrees. 195 degrees was mandated in 1978 to improve catalytic converter efficiency… that’s the only reason why I use a 180 because the engine will be healthier long term.
Actually NO.
Fiero engines are calibrated to work within a set temperature parameter in conjunction with a 195 degree F thermostat. The Thermostat does 2 things, besides letting hot coolant to pass to cool it also holds the coolant into the engine so that the engine can warm up and operate at the temperatures required for the calibration. Too low a thermostat the coolant will not stay in the engine long enough to get to the proper operating temperature.
Fiero engines are calibrated to work within a set temperature parameter in conjunction with a 195 degree F thermostat. The Thermostat does 2 things, besides letting hot coolant to pass to cool it also holds the coolant into the engine so that the engine can warm up and operate at the temperatures required for the calibration. Too low a thermostat the coolant will not stay in the engine long enough to get to the proper operating temperature.
while yes this is correct. that is NOT the issue he is having at this time, lets focus on TA's actual issue, his temp gauge is stuck at 100 degress and every sensor in the head isnt working correctly. whats the most common denominator there? the ground to the headbolt, too much thread sealer causing a poor sensor ground, coated sensors causing a crappy reading, new sensor pigtails not making proper contact, crappy splices, pinched wires\ while your information is helpful in general and everyone has chimed in on a few things we need to stay on track and think about what could have been screwed up on accident, lord knows ive messed up installing a icm and blew it up, double gasketed a IAC and chased my own tail for 6 hours trying to find the high idle before i realized i made a mistake. we are all human and sometimes we need to ask the K.I.S.S. questions and make sure its done right before we point fingers and no jelly this isnt aimed at you im just too lazy to quote everyone and i had a small nitpick
Fiero engines are calibrated to work within a set temperature parameter in conjunction with a 195 degree F thermostat. The Thermostat does 2 things, besides letting hot coolant to pass to cool it also holds the coolant into the engine so that the engine can warm up and operate at the temperatures required for the calibration. Too low a thermostat the coolant will not stay in the engine long enough to get to the proper operating temperature.
I appreciate the response, but the engine was in fact originally designed to be used with a 180 degree thermostat. When the Iron Duke debuted, the first three years of the engine used a 180 degree thermostat. It wasn't until 1979 or 1980 that the EPA mandated a 195 degree thermostat for the sole purpose of improving the efficiency of the catalytic converter. No changes were made to the carburetor tuning. I'll repeat myself because I think it needs to be repeated... the Iron Duke WAS designed to be used with a 180 degree thermostat. Switching to a 185 degree thermostat in our computer-controlled car does not appreciably affect the ECM's fuel map programming, and does not affect it enough to affect closed / open loop mode. It merely reduces the temperature of the engine overall by 10 degrees. We'd be having a different discussion of course if I went with a 160 degree thermostat, which is way too cold. For the catalytic converter, we actually have header-wrap around the exhaust shorty header and then again down the entire header pipe until just before the catalytic converter.
Again, this is not my problem though... and not sure why people are obsessing about my thermostat.
quote
Originally posted by cartercarbaficionado:
while yes this is correct. that is NOT the issue he is having at this time, lets focus on TA's actual issue, his temp gauge is stuck at 100 degress and every sensor in the head isnt working correctly. whats the most common denominator there? the ground to the headbolt, too much thread sealer causing a poor sensor ground, coated sensors causing a crappy reading, new sensor pigtails not making proper contact, crappy splices, pinched wires\ while your information is helpful in general and everyone has chimed in on a few things we need to stay on track and think about what could have been screwed up on accident, lord knows ive messed up installing a icm and blew it up, double gasketed a IAC and chased my own tail for 6 hours trying to find the high idle before i realized i made a mistake. we are all human and sometimes we need to ask the K.I.S.S. questions and make sure its done right before we point fingers and no jelly this isnt aimed at you im just too lazy to quote everyone and i had a small nitpick
I just got a new fan relay, but it's different and doesn't fit... sigh. I was going to swap it out after work just to see, but realized it was the wrong kind (sigh, Rock Auto). I'm convinced that, at least with the fan switch, it's either the relay or something with the HVAC. I don't have time during the week to jack the car up, but I remember the fan would stay on also before we tore the car apart. The AC compressor sensors are new, so I'm hoping for it being the relay.
I'll check a bunch of things this weekend, just been really busy.
I just got a new fan relay, but it's different and doesn't fit... sigh. I was going to swap it out after work just to see, but realized it was the wrong kind (sigh, Rock Auto). I'm convinced that, at least with the fan switch, it's either the relay or something with the HVAC. I don't have time during the week to jack the car up, but I remember the fan would stay on also before we tore the car apart. The AC compressor sensors are new, so I'm hoping for it being the relay.
I'll check a bunch of things this weekend, just been really busy.
Thanks!
i dont blame you, hopefully the sensor issue is just a ground that isnt all the way tight or something easy and cheap. i had almost the same issue on my 84 duke but i dont actually remember how i fixed it....it may have just been a loose ground or something in the interior i dont remember a year later
Todd humor me and unplug your temp sensor ,key on, ground one terminal then the other . The idiot light should go on on one and the other should pin the gauge to the max. if this happens then your sensor is no good. The reason I say that is your gauge will move with signal . no signal no temp reading. sleek
I did not say this was his problem, just too many people don't understand the full purpose of a thermostat and put the wrong one in. if you put a 180degrees thermostat in which ever engine, it will never stay at 180 degrees because as soon as it does that thermostat opens and the cooling cycle begins.
[This message has been edited by jelly2m8 (edited 12-04-2025).]
i dont blame you, hopefully the sensor issue is just a ground that isnt all the way tight or something easy and cheap. i had almost the same issue on my 84 duke but i dont actually remember how i fixed it....it may have just been a loose ground or something in the interior i dont remember a year later
Yeah... haha... this car was basically ready for a junkyard when I got it. Everything about it was messed up. It barely ran. I should be amazed it's where it is now. I know the gauges are good because I had them serviced, but the back flexible wiring sheet is not great. I ordered a new one so I'll have my daughter fix that. I just need the weekend to get here.
quote
Originally posted by sleek fiero:
Todd humor me and unplug your temp sensor ,key on, ground one terminal then the other . The idiot light should go on on one and the other should pin the gauge to the max. if this happens then your sensor is no good. The reason I say that is your gauge will move with signal . no signal no temp reading. sleek
Damn, that's got to be the easiest test in the world... no measuring resistance, etc. I'm definitely going to do that. Thanks Sleek!
quote
Originally posted by jelly2m8:
I did not say this was his problem, just too many people don't understand the full purpose of a thermostat and put the wrong one in. if you put a 180degrees thermostat in which ever engine, it will never stay at 180 degrees because as soon as it does that thermostat opens and the cooling cycle begins.
I'm not mad, and don't hold it against you... it's just an argument I've had many times before with a few people. I realize fuel maps are optimized for certain temperatures, but a 10 degree difference (I have a 185 degree thermostat, not 180) from 195 is not so radical a change that the ECM won't be able to appropriately compensate. I've heard people swear up and down that if I don't put a 195 in there, the pistons will cause more wear in the cyl bores, and the rings will wear out faster. I could understand this if we were talking about something like the 160 degree thermostat (that some people buy). But it seemed like one of those old wives tales. I then looked into it... I have a real aversion to vehicle regulation because so much of it is knee-jerk. I discovered that in fact... back in the 40s and 50s... most cars used 160 degree thermostats. They weren't as efficient of course, but in the 1960s and 1970s, most cars had 180 degree thermostats. This seemed to be an optimal temperature for engines to operate in, and was implemented as a result of engineering discovery and testing, not decisions made by bureaucrats. Motors like the small block chevy, the Iron Duke, and many other engines that were designed during that time... the same pistons and the same rings that were offered then, are still offered now (same part numbers by Hastings, for example). I came to the conclusion that this rhetoric is no different than when people say "all Fieros catch fire," because they heard this from somewhere. The Iron Duke's optimal engine temperature is honestly 180 degrees... as that's what it was originally designed for. I live in Florida, and we never see below ~35 degrees. When we do, the state declares a state of emergency. Anyway, I understand your point, I hope you don't take it personally, but I've done tons of research on this, and am confident that both Fiero motors are optimized for 180 degrees. I run a 195 in my Solstice because the engine was literally designed for that. Going to 195 in these existing engines was a knee-jerk attempt to make the engines run hotter so the old crappy 1st generation catalytic converters would operate more efficiently.
[This message has been edited by 82-T/A [At Work] (edited 12-04-2025).]
At what temperature does your ECU kick over to closed loop mode?
For most 80s GM vehicles, it's actually 122 degrees... for some, it's even lower. Closed loop mode for our ECMs is more of a function of when the O2 sensor starts producing a proper signal, rather than a fixed set of values in the ECM.
You can actually upgrade to a 1-wire heated O2 sensor (like the cars from the late 80s and early 90s have) that will get your car into closed loop mode more quickly. The sensor has more than 1 wire of course, but it's compatible with our 1-wire O2 sensor. There are three other wires, a ground and positive for the heater, and a ground for the O2 sensor wire (4 wires total). You can buy an upgrade kit here: https://www.casperselectron...oduct&product_id=101
EDIT: Wasn't sure if you were on the whole 180 degree thermostat thing, so I apologize. But for her car personally, it happens pretty quickly... within about 25 seconds or so. I can look at the scan data, but it happens pretty quickly.
[This message has been edited by 82-T/A [At Work] (edited 12-04-2025).]
Tangent... Didn't you upgrade the A/C compressor? The new style switches are NOT configured the same way the old ones were (even if you retained your old style compressor). One symptom of this wiring change was the radiator fan staying on all the time. But that still shouldn't make your engine run that cold. The thermostat should regulate that. To test, unplug the switches/leads on the back of your compressor. The compressor clutch can remain plugged in.
Tangent... Didn't you upgrade the A/C compressor? The new style switches are NOT configured the same way the old ones were (even if you retained your old style compressor). One symptom of this wiring change was the radiator fan staying on all the time.
I was NOT aware of this. Yeah, I upgraded to the V5. I used the old red sensor (I found a new one), and then used the new replacement high-pressure sensor. I'll definitely check this... I had no idea that others had experienced this.
quote
Originally posted by Raydar: But that still shouldn't make your engine run that cold. The thermostat should regulate that. To test, unplug the switches/leads on the back of your compressor. The compressor clutch can remain plugged in.
It doesn't actually run that cold, when I check with a laser temperature reader, I get proper temperatures at the cyl head and thermostat neck. Thanks!
I don't know enough about the V5 to comment on it, regarding the switches. Everything I've seen was associated with DA6 or HR6 compressor switches, but it was a thing.
Todd humor me and unplug your temp sensor ,key on, ground one terminal then the other . The idiot light should go on on one and the other should pin the gauge to the max. if this happens then your sensor is no good. The reason I say that is your gauge will move with signal . no signal no temp reading. sleek
Sleek... you are wise beyond your years.
I did exactly as you said... I removed the plug, stuffed a paper clip in one end and ground it out to the frame on the other end... and did it for both leads.
- Temperature Gauge pegged - Temperature Warning Light illuminated
So, the wiring is obviously good... and I know for the fact that the car isn't running at 35-50 degrees when it's 73 degrees outside. So, either I have another **** sensor... OR... I went nuts with the sealer. I used PTFE thread sealer, which I had my daughter put on the threads of all the temperature sensors. It could be this, but damn if it doesn't seem totally impossible that the sensor wouldn't be able to ground out when it's literally screwed tightly into the cyl head ... ? It's entirely possible this sensor is bad too?
[This message has been edited by 82-T/A [At Work] (edited 12-04-2025).]
Ok... I'm kind of pissed, and somewhat shocked as well.
So, ...
TEMPERATURE SENDING UNIT:
... I did two things:
1 - I ordered big gator clips from Amazon, and they arrived this afternoon. I gripped the outermost part of the sensor (the brass part), and then clipped it onto an area that has clear ground (keep in mind I have four ground straps on my engine and transmission). NOTHING. Remember, if you see above, I'd tested the leads and discovered that my wiring is in fact OK. I ground out each lead like sleek said, and I got a pegged temperature gauge, and an illuminated temperature warning light... as expected (testing the wires, not the actual temperature).
2 - I then removed the sensor, put a pot of water on the stove and used the two-speed fan connector that I cut off from the old 84 2-speed fan vestige... and I got nothing with my multimeter.
So, this damn sensor is bad. It's literally brand new?! How is it possible that it went bad? This is the second one I've used. The last one (on the old cyl head that was cracked, which was new) never worked at all. I installed this one, and it worked perfectly... and then when I swapped cyl heads, I re-used it, and now it's not working. Is it really that possible that it's gone bad? Why are all these new temperature sensors failing? They were both DELPHI which I assumed to be the higher quality one. Keep in mind, this is only the gauge sensor....
CTS / COOLANT TEMPERATURE SENSOR:
I haven't yet tested the actual ECM / CTS sensor with a multimeter yet. I did a long drive (starting the car from completely cold), and I just spent a bit more time looking at the logs...
The car starts off, or so at least the ECM thinks, with a coolant temperature of 204.3 degrees Fahrenheit. This is a cold start, with the car having sat overnight. I know it gets hot in Florida... but it's the winter, and the ambient temperature was ~70 degrees at the time of the test drive. The CTS sensor then slowly ticks down a degree at a time, until it gets down to 36 degrees... and then fluctuates between 36 degrees and 43 degrees. It'll keep doing this basically forever... never reaching the normal temperature for what is actually probably around ~190 degrees.
I look at some other things from the scanner, and it says my BLM is a constant 115, with a Flag modifier of -13 the entire time. I have no idea what this means... so I have to do some reading... but my guess is that both sensors are bad. I just find this so completely ridiculous...
Anyone have any thoughts? Am I just doing something wrong, or having bad luck? Haha...
Ok... I'm kind of pissed, and somewhat shocked as well.
So, ...
TEMPERATURE SENDING UNIT:
... I did two things:
1 - I ordered big gator clips from Amazon, and they arrived this afternoon. I gripped the outermost part of the sensor (the brass part), and then clipped it onto an area that has clear ground (keep in mind I have four ground straps on my engine and transmission). NOTHING. Remember, if you see above, I'd tested the leads and discovered that my wiring is in fact OK. I ground out each lead like sleek said, and I got a pegged temperature gauge, and an illuminated temperature warning light... as expected (testing the wires, not the actual temperature).
2 - I then removed the sensor, put a pot of water on the stove and used the two-speed fan connector that I cut off from the old 84 2-speed fan vestige... and I got nothing with my multimeter.
So, this damn sensor is bad. It's literally brand new?! How is it possible that it went bad? This is the second one I've used. The last one (on the old cyl head that was cracked, which was new) never worked at all. I installed this one, and it worked perfectly... and then when I swapped cyl heads, I re-used it, and now it's not working. Is it really that possible that it's gone bad? Why are all these new temperature sensors failing? They were both DELPHI which I assumed to be the higher quality one. Keep in mind, this is only the gauge sensor....
CTS / COOLANT TEMPERATURE SENSOR:
I haven't yet tested the actual ECM / CTS sensor with a multimeter yet. I did a long drive (starting the car from completely cold), and I just spent a bit more time looking at the logs...
The car starts off, or so at least the ECM thinks, with a coolant temperature of 204.3 degrees Fahrenheit. This is a cold start, with the car having sat overnight. I know it gets hot in Florida... but it's the winter, and the ambient temperature was ~70 degrees at the time of the test drive. The CTS sensor then slowly ticks down a degree at a time, until it gets down to 36 degrees... and then fluctuates between 36 degrees and 43 degrees. It'll keep doing this basically forever... never reaching the normal temperature for what is actually probably around ~190 degrees.
I look at some other things from the scanner, and it says my BLM is a constant 115, with a Flag modifier of -13 the entire time. I have no idea what this means... so I have to do some reading... but my guess is that both sensors are bad. I just find this so completely ridiculous...
Anyone have any thoughts? Am I just doing something wrong, or having bad luck? Haha...
nope. just a really REALLY awful year for parts. ive been scavenging them off old junked cars and using those because they work longer than a week....definitely didnt have a brake caliper, hose and wheel bearing last only 3 days last week.. honestly though ive had awful luck with delphi parts so far, ive had more of them stay functional but they get...how do i put this? they get gremlins and start to act up, ive had 3 of their icms and each one behaved radically different from the others and would cause a noticeable difference in total power, fuel economy, and for some reason mixture(?) ive had crap luck with ac delco as well but generally good luck with standard ignition products, standard motor products and extremely good luck with NTK
nope. just a really REALLY awful year for parts. ive been scavenging them off old junked cars and using those because they work longer than a week....definitely didnt have a brake caliper, hose and wheel bearing last only 3 days last week.. honestly though ive had awful luck with delphi parts so far, ive had more of them stay functional but they get...how do i put this? they get gremlins and start to act up, ive had 3 of their icms and each one behaved radically different from the others and would cause a noticeable difference in total power, fuel economy, and for some reason mixture(?) ive had crap luck with ac delco as well but generally good luck with standard ignition products, standard motor products and extremely good luck with NTK
Ugh... ok... that's crazy. I can't believe they let this stuff get produced like that. I'll see if I can find some NTK and then Standard Ignition or Standard Motor. Thanks man...
Originally posted by 82-T/A [At Work]: Ugh... ok... that's crazy. I can't believe they let this stuff get produced like that. I'll see if I can find some NTK and then Standard Ignition or Standard Motor. Thanks man...
if i had any spare 84 sensors i would send them your way since all of mine worked but alas. my garage makes a mental patient look sane at the moment because it turns out you can fit a complete workshop(2 different benches,4 full size shelves and 2 drill presses and 5 bikes on a rack plus a winch in the floor) into a single car garage with a fiero and a full size quad if you try hard enough. if v6 sensors are the same values i have quite a few of those that tested good and i bet you have a few that work as well, or maybe those 87-88 dukes have values close enough?
if i had any spare 84 sensors i would send them your way since all of mine worked ... if v6 sensors are the same values i have quite a few of those that tested good and i bet you have a few that work as well, or maybe those 87-88 dukes have values close enough?
Nah, it's ok man, I appreciate it. I have a bunch on order. I saved some of the old ones too, just need to figure out where I put them. The car runs really well, but I think it's running rich so I don't want to kill the cat. But I should be getting them in the mail soon. I also have a box of sensors, so I need to look through that. Also... I have a bunch of stuff to give you, I just need to finish with it. I have a really nice gauge set that I think all works (for an 85), but I need it temporarily to test out LEDs. I'll send it to you once AJ has swapped the bulbs over to hers. It has a perfect back panel sheet thingy... which is OK because we bought a brand new one.
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Originally posted by cartercarbaficionado:
...you can fit a complete workshop(2 different benches,4 full size shelves and 2 drill presses and 5 bikes on a rack plus a winch in the floor) into a single car garage with a fiero and a full size quad if you try hard enough.
I ordered a Standard Motor Products CTS, and guess what I got... another Delphi one.
The other sensor I ordered (the sending unit for the gauge), they actually sent me a coolant sensor for a completely different car... like maybe something from the early 2000s. Completely not the right part at all.
I'm going to end up returning both of them. But I went on Rock Auto, and some new options showed up. I ordered an NTK sensor for the gauge sending unit, and a WELLS CTS. So we'll see if I actually get what I order.
