finally had time and money to throw at this so I replaced all the sensors on the engine and threw a new distributor in. runs alot better but still won't idle below 2000 rpm and it's not drivable with the radiator fan stuck on, it's not the fan relay or temp switch (I think? it's hard to tell since I don't have a manual to tell me where the 2nd switch is) someone said it might be the ac compressor switch but it isn't the one on the dash so I'm a little lost, also typical overheating issues but im pretty sure that won't be an issue once it stops sticking it's fan on at 60 mph
...also typical overheating issues but im pretty sure that won't be an issue once it stops sticking it's fan on at 60 mph
If your Fiero has "typical overheating issues" with the fan stuck on, what makes you think overheating "won't be an issue" with the fan not stuck on? If you bought this Fiero in its present condition, and the engine actually is overheating, it's possible the previous owner jury-rigged the fan to be on all the time to try and hide a cooling issue.
IMO, the 2000 RPM idle speed is something more critical at this point than the fan. You need to find the vacuum leak.
the overheating really only became an issue with that fan stuck on, also was working correctly when the vehicle was bought just not sure what failed yet, also not sure where the leak would even be since I personally have removed all the vaccum lines and capped them off except the map sensor line and the egr line, i did do headgaskets not too long ago (as in I haven't even been able to drive the thing because it had a thermonuclear meltdown with its old distributor pickup and coil while parked) it did do this type of thing before but would stop if I messed with the tps but it would also shut off so probably not great (new one went in with a new connector wired In and soldered properly) so at least it's not a bouncy idle anymore, buddy things it might be the egr line but it's a stainless one that's only a few years old
[This message has been edited by cartercarbaficionado (edited 04-23-2024).]
the overheating really only became an issue with that fan stuck on, also was working correctly when the vehicle was bought just not sure what failed yet, also not sure where the leak would even be since I personally have removed all the vaccum lines and capped them off except the map sensor line and the egr line, i did do headgaskets not too long ago (as in I haven't even been able to drive the thing because it had a thermonuclear meltdown with its old distributor pickup and coil while parked) it did do this type of thing before but would stop if I messed with the tps but it would also shut off so probably not great (new one went in with a new connector wired In and soldered properly) so at least it's not a bouncy idle anymore, buddy things it might be the egr line but it's a stainless one that's only a few years old
Do you not have vacuum brakes anymore? I would hope you didn't cap that off haha, the most common vacuum leak is the EGR tube, especially if you've removed and reinstalled it, it is likely cracked. Have you checked your coolant level? Like Patrick said, you are not overheating because your fan is stuck on. Is the fan on all the time the ignition is on, engine on or off? Or is it only on when the engine is running, does it turn on immediately upon startup, or take a few seconds before turning on?
Yup, fan On & still "over heats" Is Not cause by "rad fan stuck on."
Engine Is Not Over heated running @ 200° to ~ 230°F no matter what claim here & elsewhere. Pushing > ~ 235°F is starting to be over heated.
Fan is On because: Engine is really Over Heating. Some Wiring Problems Forcing the Fan On. Someone "played tricks" Force the Fan On like Either a switch you flip/push or Low Temp Switch in the engine from RD etc.
Engine that is Over Heating to Boil Over can be many things. Like Many Simply Do Not Follow Fiero Coolant Fill Directions can easily over heat the engine.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Can I ask a dumb question? Is it legal to have these manuals in PDF form and offer them up as free downloads? I'm not judging, I'm just curious because I wouldn't mind backing them up as well. I just know you can still buy the paper manuals (the service manuals are usually $80), but sometimes a company will release the rights to something to help the community. I'm just curious...
Fieroinfo.com hosts a collection of Fiero manuals directly on their website.
Please note that while fieroinfo.com provides access to these manuals, it’s essential to verify the legal rights associated with their distribution and usage.
If you have any specific concerns about the legality of these manuals, I recommend seeking legal advice or contacting the website directly for clarification.
Do you not have vacuum brakes anymore? I would hope you didn't cap that off haha, the most common vacuum leak is the EGR tube, especially if you've removed and reinstalled it, it is likely cracked. Have you checked your coolant level? Like Patrick said, you are not overheating because your fan is stuck on. Is the fan on all the time the ignition is on, engine on or off? Or is it only on when the engine is running, does it turn on immediately upon startup, or take a few seconds before turning on?
it is a new egr tube allegedly and i did reinstall it during headgaskets but it was going this behavior before then anyways, coolant level is fine and I've bled the system correctly, I'm only overheating at speed since my rad fan is spinning slower than the air is coming in (gt bumper on a formula also doesn't help my case considering the missing lower dam) it's on all the time with the key on engine status doesn't matter no clicks are heard
Yup, fan On & still "over heats" Is Not cause by "rad fan stuck on."
Engine Is Not Over heated running @ 200° to ~ 230°F no matter what claim here & elsewhere. Pushing > ~ 235°F is starting to be over heated.
Fan is On because: Engine is really Over Heating. Some Wiring Problems Forcing the Fan On. Someone "played tricks" Force the Fan On like Either a switch you flip/push or Low Temp Switch in the engine from RD etc.
Engine that is Over Heating to Boil Over can be many things. Like Many Simply Do Not Follow Fiero Coolant Fill Directions can easily over heat the engine.
it got new headgaskets because during a drive the temp gauge suddenly went to 0 and the coolant was violently boiling for over 10 minutes, also the fan only started doing this somewhat recently meaning its a wiring or switch issue. but no one wants to actually tell me which switch on the ac compressor is the one to control the fan which is the last thing it could be since I've checked everything else and the relay has a signal stuck on
I will get that manual, also I've already replaced and fixed all the vac lines 4 times now including removing the stuff for the charcoal canister (properly mind you. not my first 80s gm its my 5th)because it apparantly caught on fire for the previous owner, the temp sensor for the ecu might be the issue but I'm not sure
Think about it, the fan blades are always in the airflow the same amount, even when spinning, if anything, it is still improving cooling at speed because instead of just a chunk of plastic in the Airstream, it is turning and going with the Airstream, I definitely think the air dam is the issue, the radiator gets most of its air from that, very little from the openings, especially with a license plate. Considering air will take the easiest path, at speed your air is likely going in the opening, then straight under the radiator, skipping it entirely, instead of getting forced into the radiator along with a bunch of lower air by that air dam.
cartercarbaficionado ...but no one wants to actually tell me which switch on the ac compressor is the one to control the fan....
You know that Two Switches Control the Coolant Fan Relay, not only one - right? Coolant A/C Pressure Switch @ the compressor OR Coolant Fan Switch @ the engine block
You know that Two Switches Control the Coolant Fan Relay, not only one - right? Coolant A/C Pressure Switch @ the compressor OR Coolant Fan Switch @ the engine block
One or the Either will Start the Relay
I had figured, the 84 fiero in the garage and the 1993 and 1988 s10 blazer do the same thing, just wasn't sure which Switch and I needed to be completely sure which one it was since it's expensive and if I open the ac system (empty already) then I might as well convert to r134a while I'm in there now if only I could find the water outlet for the 84
I would if there was any near me or if it wasnt 250 bucks plus shipping, not gonna throw parts on until it's dumb engine works or I give up and carb it (~1000 bucks) just because I've already replaced all but 2 sensors which made the wandering idle go away but who knows how terrible the last 2 are (one is the 02 sensor that is stripped into a circle so it's gonna wait until I decide to "upgrade" the exhaust)
Think about it, the fan blades are always in the airflow the same amount, even when spinning, if anything, it is still improving cooling at speed because instead of just a chunk of plastic in the Airstream, it is turning and going with the Airstream, I definitely think the air dam is the issue, the radiator gets most of its air from that, very little from the openings, especially with a license plate. Considering air will take the easiest path, at speed your air is likely going in the opening, then straight under the radiator, skipping it entirely, instead of getting forced into the radiator along with a bunch of lower air by that air dam.
my 68 ford had an overheating issue which was hard to track down until I took the hardwired electric fans off and put them on temp sensors, it was dumb but the fan could not spin fast enough to actually keep up with it at speed, same thing on a 2002 gtp and a 1995 gtp and weirdly enough a geo storm gsi
And this has exactly what to do with the following... "1988 fiero formula idling at 2k rpm and rad fan stuck on" ???
because then I would know if the computer was the issue on the 88 since its using a 88 computer from the same previous owner and infact the old one from this formula when it was doing the same thing and after the new computer it stopped
I'd like to step in and help. But we need to get a few things straight.
You need to tell us the whole issue and not leave out critical parts till the end.
Your fan being on is a symptom of overheating at worst, completely unrelated at best. It isn't causing overheating, period. Unless you wired it in backwards, which I doubt.
If you are overheating at speed with a GT bumper it's because you don't have an air dam. The GT nose cannot provide sufficient airflow across the rad without one, this will be most noticeable at speed when you are generating the most heat, but still won't have enough airflow.
Explain the computer situation in more detail if you believe its related. What it has to do with a 84s waterneck is beyond me.
Think about it, the fan blades are always in the airflow the same amount, even when spinning, if anything, it is still improving cooling at speed because instead of just a chunk of plastic in the Airstream, it is turning and going with the Airstream, I definitely think the air dam is the issue, the radiator gets most of its air from that, very little from the openings, especially with a license plate. Considering air will take the easiest path, at speed your air is likely going in the opening, then straight under the radiator, skipping it entirely, instead of getting forced into the radiator along with a bunch of lower air by that air dam.
The GT/aero nose is a bottom breather, and the air dam is crucial to proper cooling. The air dam creates a low pressure area behind it when moving, creating a pressure differential and airflow through the radiator. Proper ducting panels are also important. The Formula nose is a mouth breather, there is no airflow to the radiator from underneath the car.
The O/P has a GT/Aero nose on the car - the air dam has to be installed for proper airflow through the radiator.
no idea what happened but it seems to have fixed itself after a Heat cycle and aggressive drive well except for the terrible wandering idle that was the original issue,no idea why or how it's fixed now. still a broken fuel gauge but I'll get to that eventually now that it's at least running and driving minus the select cable that decided to break
I'm sure it's gonna be back on the forum again soon since I kinda hate the 2.8l and was thinking of a carburetor swap or maybe a v8, it's been so long I forgot how slow it is compared to something weighing 400 pound more and making 180 hp so it definitely needs some tuning work
The 2.8 in the Fiero will not make more HP with a carb. All you will gain is more gas being used.
You say you O² sensor has a problem? That's the first place you should start for better performance. It probably running pig rich.
it's not, just bought a new one to have one and discovered the old one was rounded off, actually seems a little lean since it appantly really hates ignition timing and wants very very little and likes to backfire or afterfire violently at random (litterally just found this out while tuning it) regardless I'm putting a wide band on it soon and figuring out the rest of its issues
You do know that when timing it the ALDL needs to be jumped to prevent the ECU from controlling spark advance..... Most 2.8's like 10 to 12 BTDC...
I haven't put a light on it yet as I don't have one, I'm just gonna set a static time of ~8 or so and sew what it likes and yes I do know. I've never bothered to ever do it since if it cranks up well its probably close enough to not matter much in my experience on 6 different 80s to early 90s gms
behavior is being super weird rn but usual for this example idle is bouncy and gets worse the longer it idles (came down to 1k for a short while before shooting back up to 2k and bouncing between like a big cam that it does not have) check engine light Is on but turns off at 3.5k rpm? also spitting 2 foot flames on shifts and launches after a spirited drive got its power back to "normal" aka can do a small peel out and slid the back out if asked to temp gauge was going between the 2nd and 3rd tick but never higher after it burst the passenger side rear rad hose (gm part 10120079) and I replaced it with a uh...better one? rad fan is still stuck on but sometimes takes a minute to do so
If you bought this Fiero in its present condition, and the engine actually is overheating, it's possible the previous owner jury-rigged the fan to be on all the time to try and hide a cooling issue.
