Ok, so I have my engine back in my car finally, with the Allante Intake and all. And now I am trying to get it running and idling properly. I am trying to set the idle with the TPS, I have the proper procudure, I just can't get it within specs. With the engine running at about 5-600 rpm, I have 1.7 Volts on my TPS signal line. Which is down from 3.2 I had before. Spec is .475-.525 Volts. Here is what I have tried to get it down,

New ground wire from sensor to computer
New chassis ground to battery
New TPS sensor
Re-grounded all PCM grounds with indiviual wires to the Tranny
Tried 2 different computers. 3 total

But still the TPS voltage reads 1.7 Volts. And because of it, I am getting terrible milage. My O2 sensor is reading a constant 6-700 millivolts.

Anyone else every had this problem with any car of theirs? Any help would be greatly appreciated and met with +'s.

Eric

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Used is such a harsh term. . . I perfer "Previously obsessed over" ;)
88 base coupe: Back on the road. "She thinks my Tractor's sexy. . . . . "
Wait. . . Did I just say I can't wait to do more work on my Fiero?. . .what, am I retarded?

quote Said by Crazy Dave "You can take Steve out of the trailer park, but you can't take the trailer park out of Steve."

shouldnt the idle be up arround 800??

post spme pics of that bad boy ( the car not Rob)

quote Originally posted by $Rich$: shouldnt the idle be up arround 800?? post spme pics of that bad boy ( the car not Rob)

When it's idling normally, yes. But when you are setting the TPS, it has to be around 450-600, I'm around 600 because my car will not idle below that with the cam that's in it.

I'll try to get pics tomorrow.

How many volts are you getting from the computer for reference voltage?

5.03V

You have a PM.

So do you.

Sorry to hijack this, but I have a related question...
I am doing this procedure for the first time and wanted to know, where do you measure the voltage at? I have the blue wires to ground/battery, so do the voltmeter leads go to the other two wires?

If you are doing this on an Allante intake, you want to measure the voltage on the signal wire. In other words, the middle wire on the TPS. Take you positive lead to that wire, [should be blue] and take your ground to the ground wire.

Anyone else have any ideas? John, other John?

I'm out in Chicago right now, so hopefully being away from my car will give me time to think about it, but I'm still very open to suggestions.

Eric

Check the other TPS pins to make sure you have ground and +5 volts. It kinda sounds like you might have plugged the other end into 12V... which is bad.

when you do the idle learn procedure set the tps at 300 rpm...this came out in a caddy tech bulliton that I don't have with me right now.....I tried and tried, i had a sail on conditio where the engine fought you from stopping all the way to idle and then idled free. I was setting the idle learn per caddy instructions, someone then posted the new bulliton I sey it with that and the sail on went away..

Dragon1/Brian

quote Originally posted by Racingman24: 5.03V

Is that measured from the TPS pin, or from the ECM?

What happens when you open the throttle? What does the TPS signal do? Go to 5? Go to 0? Go to 12?

[This message has been edited by ryan.hess (edited 09-19-2005).]

Ok, first off, Dragon1, my car will not idle below 5-600 rpm. Probably because of the cam, it just won't do it. I'm going off ShopKey instructions which were given to me by FieroMaster88 [Thanks James]. And it says to set idle at 450-600.

And Ryan, I have my wires hooked up correctly, at least I'm 99.9% sure. I have 5.03V at my referance wire, not 12. And when I increase the throttle, it goes from 1.70 to 4.95 Volts. That is, thanks to John [Rockcrawl, thanks so much. ], as he informed me that I had my power and ground wires backward. Which brought the idle voltage down, but it's still to high.

I've asked a few of the instructors out here in school, since it's a basic electricity problem, [or at least, I thought it was. . . .] and they're not even really sure where to go. I'm so out of ideas, it's not even funny.

Eric

Remove the TPS, and see if you can manually actuate (with needle nose pliers or whatever) it throughout the full range, 0.5V to 4.5V or therebouts. If you can, then you just need to drill out the mounting holes to allow it to rotate more... Some TPS's are manufactured to poor tolerances... Remember that just a small bit of rotation can mean 1/2 volt or more deviation...

I don't know how the 4.9 tps works, it might be a lever or a circle cutout that slips over the throttle shaft...

[This message has been edited by ryan.hess (edited 09-19-2005).]

Eric,
First off, The O2 sensor should never remain at any constant voltage unless the engine hasn't been warmed up for the required 3+ minutes for closed loop operation. So check the O2 sensor and wire for a break.
Your minimum air rate should be adjusted first in base timing mode by grounding the ALCL and the idle is not affected by engine accessories. Then check and adjust the plunger length on the IAC Valve. Now would be the rightr time to set the TPS Voltage.
You may be using a TPS from a 4 cylinder engine with may have solved some of the clearamce problems with the weatherpack connection but using the 4 cyl. tps flip-flops the two outside wires and a slight enlargement of the adjustment slots may be needed.to attain the .54 volts.(min. voltage throttle closed)

Here...I found it......This helped my problem...

Group Ref.: Engine

Bulletin No.: 316006A

Date: November, 1993

SUBJECT:
SLOW DECELERATION WITH CLOSED THROTTLE ABOVE 5 MPH
(READJUST AIR RATE)

MODELS:
1990-93 CADILLAC DEVILLES, ELDORADOS, FLEETWOODS, SEVILLES, AND SIXTY SPECIALS (EQUIPPED WITH 4.5L OR 4.9L ENGINES)

THIS BULLETIN IS BEING REVISED TO CORRECT THE WARRANTY STATEMENT, AND CANCELS AND SUPERSEDES BULLETIN 316006 PUBLISHED OCTOBER, 1993.

Some owners may comment about slow deceleration with closed throttle above 5 mph. This may be particularly noticeable after performing bulletin T-93-44 (Corporate bulletin 016540R) even though all engine adjustments have been set according to published service information.

To correct this condition readjust the minimum air rate to between 400 and 450 rpm, the TP Sensor setting to .55 volts, and reset TP Sensor/idle learns using the procedures listed in the appropriate Service Information Manual.

For warranty purposes use:

Labor Operation: J6358

Labor Time: Use published labor time

Dragon1/brian

quote Originally posted by Bazooka: Eric, First off, The O2 sensor should never remain at any constant voltage unless the engine hasn't been warmed up for the required 3+ minutes for closed loop operation. So check the O2 sensor and wire for a break. Your minimum air rate should be adjusted first in base timing mode by grounding the ALCL and the idle is not affected by engine accessories. Then check and adjust the plunger length on the IAC Valve. Now would be the rightr time to set the TPS Voltage. You may be using a TPS from a 4 cylinder engine with may have solved some of the clearamce problems with the weatherpack connection but using the 4 cyl. tps flip-flops the two outside wires and a slight enlargement of the adjustment slots may be needed.to attain the .54 volts.(min. voltage throttle closed)

I don't want to be insulting, because it would appear that you are trying to help, but do you know what you are talking about? Yes, the O2 sensor voltage should not stay the same. . .unless there is a problem, which I have.

Second, you should not have to check and adjust the plunger length on the ISC, as it should be either removed, or jumpered to completly pull it off the throttle plate linkage. When setting the TPS, the ISC can not be controling the throttle, as that will make your measurment irrelevant.

Lastly, you can't use a 4cly TPS, or connector with this set up. You have to use an Allante TPS, with either that plug, or a plug from a V6 Fiero. In which case, then yes, the power and ground must be switched, which I did, as stated in the post above.

And to everyone else, suggesting that I slot the holes more, I don't think I stated this before, [I don't have time to go back through all the posts right now, time is limited] But even with the TPS removed from the throttle body, I still get 1.70 Volts coming out of it. So that idea will not work, as much as I wish that it would.

It's wierd, no one seems to be able to come up with an answer for this, even the seasoned veterans that have been in the field for 20-30 years. And even though it seems extremly difficult, when I figure it out, it's probably going to be something so simple, I'll want to kick my own ass.

Eric

PS, please keep the comments and suggestions coming in.

quote Originally posted by Racingman24: And to everyone else, suggesting that I slot the holes more, I don't think I stated this before, [I don't have time to go back through all the posts right now, time is limited] But even with the TPS removed from the throttle body, I still get 1.70 Volts coming out of it. So that idea will not work, as much as I wish that it would.

Gotcha. Okay, here's my test procedure:

Get your DVM, and tie the ground clip to a reliable ground, such as the engine block, or whatever's handy. Remove the TPS connector. Check the 3 pins "key on, engine off". You should see 0 volts twice, and 5 volts. Plug the TPS sensor back in. Check the same 3 pins, you should see 0 volts, 5 volts, and something in between. Keeping the meter on the "between" pin, check to make sure when you actuate the throttle, it gets to 5 volts (I know you said you did this... just double check ). I want to make sure it gets to 5 and not 7.

Also, while you're at it, check the resistance from the ground pin to the engine ground. Should be very low, like an ohm or less.

Assuming all of the above checks out, you have to have a faulty TPS sensor. The parts store could have given you the wrong one. Also before I have gotten the "wrong" part in the "right" box. A simple swap would fix that. Unfortunately a lot of stores don't offer warranties on electrical parts, so you might have to suck this one up to stupid people.

[This message has been edited by ryan.hess (edited 09-20-2005).]

quote Originally posted by Dragon1: Here...I found it......This helped my problem... Group Ref.: Engine Bulletin No.: 316006A Date: November, 1993 SUBJECT: SLOW DECELERATION WITH CLOSED THROTTLE ABOVE 5 MPH (READJUST AIR RATE) MODELS: 1990-93 CADILLAC DEVILLES, ELDORADOS, FLEETWOODS, SEVILLES, AND SIXTY SPECIALS (EQUIPPED WITH 4.5L OR 4.9L ENGINES) THIS BULLETIN IS BEING REVISED TO CORRECT THE WARRANTY STATEMENT, AND CANCELS AND SUPERSEDES BULLETIN 316006 PUBLISHED OCTOBER, 1993. Some owners may comment about slow deceleration with closed throttle above 5 mph. This may be particularly noticeable after performing bulletin T-93-44 (Corporate bulletin 016540R) even though all engine adjustments have been set according to published service information. To correct this condition readjust the minimum air rate to between 400 and 450 rpm, the TP Sensor setting to .55 volts, and reset TP Sensor/idle learns using the procedures listed in the appropriate Service Information Manual. For warranty purposes use: Labor Operation: J6358 Labor Time: Use published labor time Dragon1/brian

Could someone please post the "procedure listed in the appropriat service manual" I would love to finally get my idle below 2000 when am rolling along and press in the clutch.

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85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

quote Originally posted by Capt Fiero: Could someone please post the "procedure listed in the appropriat service manual" I would love to finally get my idle below 2000 when am rolling along and press in the clutch.

This is directly from Shopkey, which FieroMaster88 sent to me. It should be the same for you, even though you don't have an Allante Intake.

quote From FM88 in a PM This is done while engine is at operating temperature (85 degrees centigrade). If idle speed adjustment is required remove cover over idle speed screw and adjust idle. 1.Fully retract or remove the ISC motor. Make sure the throttle lever is resting on the minimum idle screw. 2.Check the minimum idle speed. It should be between 450-600 RPM. 3.If the engine stalled at minimum air (ISC retracted/removed) check the primary throttle blades for carbon buildup. Clean throttle body. If the minimum idle speed is still out of limit adjust useing the idle speed screw. Throttle position sensor adjustment. (preform before reinstalling ISC motor) 1.Measure the TPS Signal voltage by connecting a high impedance digital voltmeter to the tps test point. With the meter set to the 2-volt scale, connect positive lead to dark blue wire, and negative lead to black/blue wire. With engine running, loosen TPS screws just enough to permit sensor to be rotated. Adjust tTPS so that voltmeter reads .475-.525 volts. Tighten TPS mounting screws. 2.Turn off engine and reinstall ISC motor. Clear all codes from PCM. Start engine and verify proper idle.

per Rockcrawl about a year or so ago...

Make sure the throttle plates and bores are clean before you start. Also make sure you don't have any vacuum leaks. Jumper ALDL A and B to enter the set timing mode. Verify timing at 10* BTDC and remove jumper. a).Disable the alternator by grounding the small brown wire, there should be a green connector inline if it's anything like a Cadillac harness. Disconnect the ISC motor where the main harness attaches to the sub harness. Attach two jumper wires to the blue wires of the sub harness. Connect one jumper to ground and the other to bat positive momentarily until the ISC is fully retracted. If it extends, reverse the polarity to make it retract. When it is fully retracted, the throttle lever should be resting on the minimum idle screw. If the throttle lever is touching the ISC plunger at full retraction, use a pliers to turn the plunger in until it's not touching. b).Use the minimum idle screw (recessed torx) to set the idle to 525 rpm. With the throttle lever resting on the minimum idle screw, set the TPS to .50 volts. c).Now you can extend the ISC by reversing the polarity of the jumpers. At full ISC extension, the TPS should read between 1.15 and 1.20 volts. Adjust the ISC plunger in or out with a pliers to obtain the correct TPS voltage. Retract the ISC. Reconnect the ISC to the main harness. Turn the key off and wait 20 seconds to allow the ECM to perform a TPS learn. d).Cycle the ignition on and off once more. It takes two cycles for a sucessful TPS learn. Perform and idle learn. Run engine until coolant temp is greater than 176*. Allow engine to idle in park for ten minutes. With brake applied, allow engine to idle in drive for at least three minutes. The ECM will command a 600 rpm idle. If it's not idling at 600 +/- 50 rpm after doing this procedure there is something wrong.

Dragon1/Brian

Thanks Racingman24 and Dragon1 I think with the a combintaion of the 2 I will be able to set it up with the 5spd on my car. I honestly belive this is costing me a bunch of fuel milage during in town driving.

I will post back with results later today. Pluses all around.

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85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

LOL, well this has been fun so far.

I get print off both sets of instructions and go out to the car after dinner around 7pm.

Find all the related wires I need to tinker with. I decide seeing as this will be a pretty common thing to reset every time I unhook the battery I might as well make up a nice harness with 2 ground leads and a hot lead that plugs into all the connectors and such.

So I make up a nice harness that plugs into the ISC motor and the alternator jumper wire. I test it and I can move the motor in and out at will. OK Happy. So now I grab the scan tool and plug it into the DATA PORT. Punch in all the good doo daa info and start running though the data monitor mode. Coolant Temp Sensor -40F Uh Oh this is not good. Ugh. start looking for broken wires cant find any. Call up John, he walks me through testing things with ohm meter. I pull out the plug at the ECM and stuff test lead into it, and then run test lead out to sensor plug in engine pay. (long leads) and it comes up good. OK so I test the sensor by hooking the ohm meter to both sides of it, I don;t get an audible sound. He says this is bad. So we do a quick interchange check on-line and find out the stock Fiero is the same. So I steal the one out of my Fiero and then bench test it. What the heck it won't give a tone either. So I switch to the meter mode and get 3.543 out of it. Hmm, So I run back to the car and test the sensor on the car and get 1.546. I plug the connector back in and retest with the Scan Tool. This time I get 105F OK so the sensor is now fixed. Now back to the TPS voltages and playing with the ISC motor. So with the motor all the way in, the TPS is putting out .33v and at full extension I am getting .88v according to the instructions it should be .50 and 1.17 (average) OK now to find a torx to reach down and loosen the 2 screws. Spend 30min trying to find something that will fit. Finally come up with the idea to take a T25 torx bit wrap masking tape around the outside the bit and press it into the boxed end of a very small wrench. This seems to work perfect. I do a quick adjustment and set the TPS to .50 closed and then try it open and only get 1.05 so I turn the screw on the ISC motor out until I get 1.19 and call it good. It is now 9pm with 2 small kids sleeping 30ft from where my car is parked I don't want to start the car, so I pack it all up and put it away until tomorrow.

I guess the temp sensor issue was just a bad connection and it seems to be fine now. I hope to have it all fixed tomorrow evening and then I can report back as to how it is working.

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85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

It's normal for it to go open loop at idle, the O2 sensor doesn't stay hot enough to work properly. A heated O2 sensor should take care of the problem, but it's really not a problem.

Problem solved then?

Not mine, yet anyway. I'm going to do some checking on it tomorrow, I just got back from Chicago, on a very delayed flight, and didn't get a chance to look at anything tonight. Soooo. Of course, I'm not really sure what I'll be checking. John, you have any other ideas?

Eric

Ok is the alternator suppose to be grounded (disabled) during the 10min idle learn.

When I did the idle learn, I hooked the ISC motor up and removed the ground (enabled the alternator) while it sat for the 10min.

The darn thing still idles at 1800-1500 until I come to a near complete stop then it drops to like 1000. I was told that my chip had the idle programed for a 1000rpm idle because of it being a stick.

Thanks for any help anyone can offer. Any suggestions on the O2 sensors not moving off of the 444mv reading. They are brand new NTK sensors. 2 wire kind.

questions I had asked...

I have some questions for those that got it to work right...
a). is the car running or just the key in the on position???
b). the motor doesn't idle for very long at 525 rpm, is this a nesscesity???
c). again, is the motor running cause this revs it up very high???
d). is this a motor start or just turn the key to on position???

Answers from Rockcrawl...

a) doesn't matter.
b) If it will not idle at 525 RPM with the ISC retracted then you have a problem.
c) engine not running.
d) key on, engine off.

Here, This is the link
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20050119-2-049097.html

Dragon1/Brian

[This message has been edited by Dragon1 (edited 09-23-2005).]

Anyone else have any suggestions on the topic of the thread? About the stupid TPS. I've tried everything I can think of, and nothing is working. Nothing.

James, if you are still reading this, I'm going to send you one of my TPS's and have you plug it in and see what it reads.

Eric

I hate this car. Anyone want it? I have a Turbo car I want back.

Ok, so I think I may have the problem figured out. . . . I think, I have to spend another 115 bucks to find out.

I was messing around with it tonight, and still could not get a decent value out of it. I's gettin' pissed. So, I stole the TPS from Rob's TPI and plugged it in. Sure as sh!t, no voltage down low, and slowly increasing to 4.95 volts. Working just fine. As I said before, I tried a new sensor, but as I know from the shop, new doesn't always mean good. That, and a while back. . .after I put 3 carquest fuel pumps in my Blazer in one year, I finally took my head out of my anal cavity and decided to not buy after market electronics for my car. AC Delco Only. Well, for some stupid reason, I strayed from that this time. And look where it got me, pissed and upset.

Of course, no one in town has it, I might be able to get one tomorrow if things work out perfectly, but I'm not holding my breath.

So, once I get this stupid part, I might actually get the thing to run right. Hopefully.

Just wanting to update any watching this thread.

Eric

Cool! Hopefully that will fix it. I always buy AC Delco electronic parts for my cars.

O yea, I forgot to add, the reason I can't use the TPS from Rob's TPI, is because they are mirror images of each other. On mine, the swing arm rests at the top and pivots down, on the TPI, the arm rests at the bottom and pivots up.

Just in case you guys were wondering why I just don't use that one.

Eric

quote Originally posted by ryan.hess: Assuming all of the above checks out, you have to have a faulty TPS sensor. The parts store could have given you the wrong one. Also before I have gotten the "wrong" part in the "right" box. A simple swap would fix that.

<cough cough>

Alright, it's official, I'm the biggest dumbass in the world.

You know how GM uses certain wire colors for certain plugs? You don't? Then go lay by your dish.

For the rest of you. . . .

Here's what I did. When I did the Allante Swap, I found out that all my plugs and sensors would work, with one exception, the TPS. Ok, fine, I just have to get a connector from a V6 Fiero and plug it in, since it's the right connector. Ok, cool found one. And since GM uses, you know, the same colors for everything, I thought, hey, just connect the Grey to Grey, the Black to Black, and the Blue to Blue. Well, the Power and Ground were backward, which should have tipped me off, but didn't.

I switched them, but still didn't get the right voltage out of this lame ass sensor. Grrr. As stated above, I tried everything I could think of. Until, I finally pulled my Caddy Service manual back out, and with no regard to the color of wires, I hooked the sensor up souly on Pin Letters. A, B, and C. And what do you know, the F'in sensor works great. Hence the reson the small block TPS from the TPI [I love saying that. ] worked right. Wires in the right place.

I am so pissed but happy right now. You would think GM would use the same color wire for their sensors, o wait, they did. But then Caddy has to come in and F everything up by going and saying, "O sure, we'll use those connectors, and the same wire colors, but just to mess with people doing swaps into Fieros, lets swap the pin connections around. hehehe."

I am going to ***** slap the person that thought this was a good idea. Grrrrrrrrrrrrrr. But hey, at least I got it figured out.

There you go, now you could be a Ford mechenic. Ford likes to use different color wires in the car from what the schematic says.

I'm glad you figured it out.

quote Originally posted by Racingman24: And even though it seems extremly difficult, when I figure it out, it's probably going to be something so simple, I'll want to kick my own ass.

hehehehehehe....

Wow...