I have a 1986 Iroc, with 305 tune port fuel injection. The problem is an engine surge whenever I release the throttle and also at idle. If I don't push throttle down at stop sign and hold brake also, the engine dies.
Local mechanic tried to run codes but the computer wont give a read out.
I would really appreciate some help.
Bill

Does the "Check Engine" or "Service Engine Soon" light work, if not check to see if the bulb is burnt out, the computer will not function without it.

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Leo Paugh
MCC #017
www.clark.net/pub/chevelle/mcc.htm (http://www.clark.net/pub/chevelle/mcc.htm)
If you have no fear, you're not going as fast as you could.

Light is probably out or something.Sounds like the throttle position switch.Easy fix or check. Three wires coming off of it one is constant 5volt feed two is ground three is feed for ECM should be .525 volts at idle and increase to right at 5 volt as you open the throttle have to use jumper wires between connection and TPS its adjusted by loosening the 2 screws and turning TPS to .525 at idle about $30 at store.Check does require digital volt meter.

Yes, the light does work. It usually comes on when the car acts up.

<BLOCKQUOTE>quote:</font><HR>Originally posted by chev64:
Does the "Check Engine" or "Service Engine Soon" light work, if not check to see if the bulb is burnt out, the computer will not function without it.

<HR></BLOCKQUOTE>

<BLOCKQUOTE>quote:</font><HR>Originally posted by My Iroc:
Yes, the light does work. It usually comes on when the car acts up.

<HR></BLOCKQUOTE>
Check engine light seems to be OK. When I cross the terminals under the dash for a code, all it ever shows is the code for MAF sensor, which I have changed twice from different auto parts stores.
When a tester is inserted into the slot under the dash no data is sent to the tester.

Try this out.Remove ducting from throttle body so you can see throttle plate.Open throttle by hand and see if there is a bunch of hard black carbon called "coking" all built up in there.It's blocking the air from getting into the engine with throttle closed.Idle air control passage might have that in there as well.Get some carb spray and a firm toothbrush and get that throttle body cleaned up.I have personally seen this a few times on port fuel injected engines and after getting all that coking cleaned out the engines ran mint.Try it out.Also not to rip on anyone's answers but the computer "will" work just fine without the check engine light.Gm would not have their computer 'shutdown' because of a bulb burning out!

[This message has been edited by sschevyfan (edited 12-26-2001).]

Any help would be helpfull. I spent the summer swaping a 305 tpi for a 350 tweaked to a 420+ hp 366. ever since the computer has been tweaked. I've been gettin a hard code 34 ever since. check all sensers i think and swaped mass, ecm(not chip), and relays. everything seems ok except the code, a really rich fuel mixture smell, and the same surge when its cold out. any thoughts i'm starting think about looking in to an aftermarket fuel manegment system ,but if i can find one its going to $$$$$$$.

help.

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1987 Electric Yellow IROC-Z
350 TPI Tweaked to 420+ hp 366
700R4 with TCI 2500 stall
Richmand 3:73 posi

Just a thought. If it's an automatic you might try checking the lock up tourqe converter switch. This is a common problem on new cav's and sunfires as well as several fords. Just a thought
also, It won't show any codes for this problem

[This message has been edited by blown67ss (edited 12-28-2001).]