Question about 1987 Pontiac Firebird

2 Answers

High Idle 1985 Firebird 2.8 95,000 mi how do I lower the curb idle, I have cleaned IAC, but it only worked for 2 seconds. I have found a vacum leak and fixed it but it still idles high. There was a lot of carbon on IAC so I put some fuel injector cleaner in the gas. I have unplugged the wires to the IAC TB, and no difference in running or to the idling. The engine light is on, but I can not drive car to test, or read codes. I am limited in money and time, I am a novice mechanic. I do not know the history of car, but it leaks everywhere. Ps. what controls the fan and where does it hook up? They have it wired directly. Biggggg project, but I am enjoying getting dirty...

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  • 20 more comments 
  • robert_c_pol Mar 02, 2009

    I will check the codes, thanks. As for the engine it is a six, 2.8, Where on the engine is the Thermostatic bulb located, and does the positive wire go there? And where does the other one go? I found a plug under the rear of the intake that was broke off, it has a orange male plug, do you have any suggestions on that? Thanks a lot.

  • robert_c_pol Mar 11, 2009

    I have put a new relay in for the fan. Blk and red wire one. Still no fan. I am wondering if the missing AC has something to do with it? I have also replaced the fan sensor. Still no fan. What is the sensor next to it? Left front, intake, it is larger than the other. Local stores do not know what it is. I think it is a temp sensor, at least it looks like one. I had a hard time reading/interpreting the codes. It appears to be 33, 34, or 23 I am not sure.

  • robert_c_pol Mar 11, 2009

    Also, I have cleaned the MAP sensor with MAP cleaner, cleaned the IAC fixed all vacuum leaks and verified the routing. I hear a funny noise when the IAC is working. Is that normal? I tried to adjust the IAC manually, but the screw is messed up. It idles high, and after a few minutes it starts to idle higher and higher and higher. Stops about 2 grand, and I have to shut it off so it will not ruin the engine.

  • robert_c_pol Mar 15, 2009

    I have replaced the IAC and put on new tappet cover gaskets, and now I have different codes. 22 and 44. Can you help?

  • robert_c_pol Mar 17, 2009

    I have torn the top of the motor off and put new o rings on the injectors, installed a new tb gasket, and checked all vacuum lines--no leaks. I have also put on a new dist cap and rotor button, and nowI I have new codes 22 and 44. I took the tps off and it is movable, but at the same time i grabbed the spring on the other side and if felt like it was sticking. I do not know what else to do. The tb was pretty clean, the injectors could be replaced, I guess, but I am at a loss. You mentioned low voltage, how can I check and what do I need to do if it low? Thanks, Robert

  • robert_c_pol Mar 17, 2009

    Yes.

  • robert_c_pol Mar 18, 2009

    The TPS appears that it has been replaced, it still has a sticker on it and it is shinny, unlike the rest of the car. They broke one of the screws off in the TB. I pulled it, TPS, off and it moves like it is supposed to. I did notice that the spring on the other side did not move as easy as I thought it should. I have never seen it working. I have watched it and it never moves. When is it supposed to move? On the other hand, I have removed the MAF while the car is running and it dies, so I think that the MAF sensor is working. I will try running it without the TPS hooked up, after I clear the codes. Thanks.

  • robert_c_pol Mar 18, 2009

    I ran the motor with the TPS unplugged and the only code I got was 12. I hooked up the TPS and then I got code 22. I did not get the lean mixture one this time, code 44. So, what does this mean?
    Yes, the spring on the TB. I cleaned that today with carb cleaner. The engine runs fine when you first start it, 1500 rpm. Then the rpm climbs. I still have the problem with the electric fan not coming on. When I direct wire the fan to the battery the engine idles down, but as the engine warms up, it revs, and starts knocking; this happens about 2 grand. I shut it of immediately. THANKS Robert


  • robert_c_pol Mar 18, 2009

    Oh, there is no change when the tps is disconnected. The engine still idles high, but there is no code. At least we have got several of the other codes gone! Thanks a lot. Robert

  • robert_c_pol Mar 18, 2009

    How do I change the ECM? Are there any certain things that I should do, or shouldn't do? Can I upgrade it at this time, and what do you reccomend?

  • robert_c_pol Mar 20, 2009

    Hello, today when I started it up the engine it was running rough. I drove to my in-laws, two blocks away, and it was as if it was running on two cylinders. It started backfiring when I started it. This thing is driving me crazy. I have replaced all the gaskets on the top end, cleaned everything, and replaced iac, thermostatic temp sensor, cold start sensor, and replaced the o rings on the injectors. I put new plugs, cap and rotor, wires were good. I did have a problem with the screws not fitting right on the distributor, but it was some what tight. The map sensor is working because the engine dies when it is unhooked. I did have to bring cylinder to the top to find the number one plug, but it started right up. Could the timing be off? I was thinking about loosening the distributor and setting it by ear because I do not have a timing light. Any suggestions would be verrrry helpful, thanks.

  • robert_c_pol Mar 21, 2009

    I have changed the ECM and I still have the problem with the high idle, but on the brighter side, my fan is now working! I cleaned the TB again, no help. I guess that maybe I should change the TPS; I don't know if this will help, but that is the only thing that I have not changed. Any suggestions? I am still having code 22. thanks Robert

  • robert_c_pol Mar 22, 2009

    I will change the tps. I set the timing today and it is idling good now....but there is no power when I give it gas. The throttle is sticking, it is hard to press the accelerator pedal. I tried it unhooked, the pedal, and it works fine. This tells me that it is the tb. I oiled the tb today with wd-40, but it did not help. I have cleaned it, and it still sticks. Do you have any suggestions on how to fix that problem. At least now, I am not getting as dirty! I have changed and cleaned everything. Thanks Rob

  • robert_c_pol Mar 22, 2009

    I set the timing at 10 degrees. What is the bypass and where is it located? Could you explain. thanks



  • robert_c_pol Mar 22, 2009

    Where do the wires go? This cars electrical is so screwed up it is not funny. They have rigged everything. So, more help is needed. Is there a picture in my haynes manual? Do I unhook it before I start it, or unhook it while it is running? Thanks

  • robert_c_pol Mar 23, 2009

    The only single wire with a plug was a brown one, and I disconnected that, set the timing again at 10 degrees. Now I have power, but I still have the original problem of the high idle. I still have code 22. So, come Friday I will put a new TPS on it. Is there any good ways of cleaning the TB? It is still sticking and so is the RPM, or tack. It stays at 2 grand when the motor is shut off. Does that mean anything? Thanks Rob

  • robert_c_pol Mar 23, 2009

    Yes, it is way above 10. So, is that right? It runs smooth, but it is idling high. Oh, by the way, I have never asked what should the idle be set at. The book states 450 in drive but it does not state what the curb idle is. Should it be about 1 grand, or 11 grand, or should it be lower. This engine is running smooth, starts fine, and now has power. It purrrrrrs. Thanks Rob

  • robert_c_pol Mar 23, 2009

    I have used carb cleaner, and I even used a screwdriver with a rag to lightly scrape of the carbon. I have it pretty clean but it is still sticking. I put WD-40 on the spring outside, and even sprayed a little inside--no help. I was careful not to scrape up the sides so that no air would get in. I am at a loss. Other than replacing the whole thing, which I think that I should not have to; is it possible to take apart the whole thing without messing it up? I tested the cable and it is fine. I have no clue...

  • robert_c_pol Mar 23, 2009

    Thanks both of you! I will keep you posted. Robert

  • robert_c_pol Mar 30, 2009

    Hey guys, the bird is purring...I replaced the tps, but I could not set it with the jumper wires. I could not get a reading, only on one wire, so I set it by ear after it was warmed up and it is running good now. The injection cleaner worked great! Thanks a lot, both of you. Robert

  • robert_c_pol Apr 03, 2009

    Hey guys I am back. I have another question. What causes an alternator to keep burning out? It has been replaced two times, but I do not know if they were both bad already, they were used. I am wondering if the old ecm could have caused it?

  • robert_c_pol Apr 04, 2009

    Dudes, now I am getting a code 32 egr? Does the vacuum going to the egr **** air, or does the hose going to the egr **** the air. I have no vacuum to the egr either way, and I am wondering if that is causing the code. I have tried to hook up the vacuum the way the diagram shows but there is not enough detail because there are more hoses than the picture on the hood shows. I have suction from the intake, tb, and the pvc. The hoses coming from the "?" above the egr on the right side. I do not know what it is called, but the hoses from there go to a splicer and then to the egr diaphragm and there is no vacuum from there. I think it might be the valve to the IAC? or egr solenoid? I am not sure, but something there should have suction, shouldn't it? My manual does not state it...

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  • 319 Answers

What size engine does it have? there is usually a throttle advance/decrease screw on the throttle body. back it off a few turns, and see what that does. the fan control is a thermostatic bulb sensor that screws into the intake manifold.

Have you checked the MAF?

Posted on Mar 02, 2009

  • 5 more comments 
  • Patrick Cowan
    Patrick Cowan Mar 11, 2009

    Replace your IAC

  • Patrick Cowan
    Patrick Cowan Mar 18, 2009

    the TPS may LOOK new, but they can come bad out of the box...

  • Patrick Cowan
    Patrick Cowan Mar 18, 2009

    i was thinking the same in regards to the ECM being shot...sounds like its misreading

  • Patrick Cowan
    Patrick Cowan Mar 22, 2009

    the bypass line is up at the firewall on the pass. side. gray connection on a brown wire

  • Patrick Cowan
    Patrick Cowan Mar 23, 2009

    TB cleaner spray is good or carb cleaner, its what i use. as far as the TPS, i'd certainly try that.

  • Patrick Cowan
    Patrick Cowan Mar 23, 2009

    im at a loss, by now, i would have changed throttle bodys...

    get a can of parts cleaner, unbolt the throttle body, and drop it in a tub of the parts cleaner over night. then oil up the spring and throttle cable mounts with white lithium grease.


  • Patrick Cowan
    Patrick Cowan Apr 03, 2009

    A faulty battery could be the cause, or just a coincidence.

    buy a new one with a warranty!


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  • 4,669 Answers

You can scan the computer for codes with a paperclip. Find the ALDL connector under the dash. Jump the paperclip from the A terminal to the B terminal. Turn on the key and count the flashes of the Check Engine light. For Example 1 long flash followed by 2 short flashes would be code twelve. It will repeat each code three times and then start over. Code 12 will always be in there, it means the engine isn't running. But every code that comes up after 12, write them down and post them. I'll tell you what they mean and we will go from there.

Posted on Mar 02, 2009

  • 12 more comments 
  • Clint Smock
    Clint Smock Mar 11, 2009

    33 and 34 are MAF/MAP codes and 23 is an Intake air temp code. Have you ran the engine with either of these sensors unplugged? Try unhooking the battery to clear the codes and then restart the engine. See if the codes return. Although I agree with djicenova, I think you have a defective IAC.

  • Clint Smock
    Clint Smock Mar 15, 2009

    22 is TPS low voltage and 44 is lean exhaust.

  • Clint Smock
    Clint Smock Mar 17, 2009

    Do you still have the high idle?

  • Clint Smock
    Clint Smock Mar 17, 2009

    A defective TPS can cause high Idle and you have a code for TPS, You said you get no change when you try running it with the TPS unplugged? Did you get the 22 code from running the engine with the TPS unplugged?

  • Clint Smock
    Clint Smock Mar 18, 2009

    The spring on the other side of what ? The throttle body? Just so you know I'm toying in my mind with the idea that your ecm is junk.

  • Clint Smock
    Clint Smock Mar 19, 2009

    With the Tps off the throttle body, move the throttle open. Does the tap turn that goes in to the TPS? It's weird that you don't get a code 22 with the TPS unplugged. You should. Also if you take out the ECM just unhook the battery first. It is behind the dash on the passenger side floorboard. You have to transfer the MEMCAL chip to the new computer or if you want to upgrade, replace the MEMCAL chip with a performance chip.

  • Clint Smock
    Clint Smock Mar 19, 2009

    I'll post a wiring diagram for the cooling fans tomorrow so we can figure those out too.

  • Clint Smock
    Clint Smock Mar 22, 2009

    If you are still getting code 22 I would change the tps.

  • Clint Smock
    Clint Smock Mar 22, 2009

    What did you set the timing at? Did you set it with the bypass line unhooked?

  • Clint Smock
    Clint Smock Mar 22, 2009

    The bypass is a single wire to the distributor that you need to unhook before you set the timing, I'll have to look up the location but it should be near the distributor. It is a single wire plug, the wire should be tan with a black tracer.

  • Clint Smock
    Clint Smock Mar 23, 2009

    You can clean it with carb cleaner. The tach staying at 2,000 means nothing. When you turn the key back on it should go to zero. If you set the timing with that brown wire unhooked to 10 and then checked the timing with the brown hooked. It should be way above 10. If it is you unhooked the right wire.

  • Clint Smock
    Clint Smock Mar 23, 2009

    Yes timing should be good. I would remove the throttle body to clean it. The carbon on the inside is likely what is causing it to stick. The Idle speed warm should be about 850 rpm.

  • Clint Smock
    Clint Smock Apr 04, 2009

    No the ecm can't cause it. just coincidence. I would buy a reman if the one you have on it goes bad again.

  • Clint Smock
    Clint Smock Apr 05, 2009

    I'll look up the vac diagram and repost.

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