92 lumina 3.1

[59 agnj]

still the same car, and still the coolant level light on ,but have come to the conclusion that it must be a bad sensor, oh well . now I have a bigger headache , it starts & runs great until it's warmed up to operating temp , then it dies whenever you come to a stop or let the rpm's get too low ,I tried to get a code out of it and after code 12 it gives out a code 35 which is non-existant in my list ,I even called a guy down the street to ask him if he ever gets a bad code , buthe's never heard of it ?????

[discnik]

Code 35: Idle speed was over 150 RPM outside the desired engine speed for 20 seconds.

Have you checked/ cleaned: IAC Valve, Mass Air Flow sensor/ Throttle Position Sensor/ Engine Coolant Temp. Sensor ?

And I am sure I have forgotten something.

Sorry about the long list but these could cause your symptoms.

[59 agnj]

the coolant temp. sensor, yes :the MAF yes: but the IAC , no . thanks for the info , also where did you get the code 35 from , my books do'nt have it , and neither did 2 shops in my area , or so they said : even though they probably was hoping on my just bringing the vehicle in so they could make dollars . thanks again ,59 agnj

[discnik]

MPC Publishing Smart Spec 2003. We use alot of MPC's training DVD's at our shop to keep up on the latest diagnostics.

[richtazz]

My internet OBD-I code source shows this:

35: Engine idle speed is either 300 RPM above or below the desired idle speed for 50 seconds. Pretty much the same, the only difference being the RPM range (150 vs 300)

The first thing I would check for is broken/disconnected vacuum line(s). A vacuum leak will affect idle RPM and trip this code. The above suggestion to check the IAC is good, and also check the throttle body for carbon deposits that may be keeping the throttle from completely closing. Just for clarification, a funky TPS or ECT will usually trip a code (although I wouldn't rule them out completely), and this car doesn't have a MAF.

here's a link to a pretty decent OBD-I code database for GM:

http://www.troublecodes.net/GM/

[59 agnj]

have removed the throttle body & cleaned ,replace IAC & TPS , a little better but still as soon as it gets warmed up it either tries to die or as soon as throttle is applied it stumbles horribly and sometimes even lightly backfires thru the intake now , I am about ready to just take it in and tell them , fix the thing ,also it is keeping a constant 34 pounds fuel pressure at the rail ???any other last ditch ideas before I take it to someone with a $ 100,000.00 computer to tell them whats wrong ?

[kingtut1980]

Could be a vaccuum leak. This will cause a code 35 due to an abnormally high idle speed. Have you checked the EGR? If an EGR valve sticks slightly open it will cause big time idle problems because it allows exhaust gas into the air intake at a time when the engine can't handle it. (at idle) Back in the old days it was easy to test EGR systems, I am sure you have a digital valve which incorporates three solenoids and three different "pintles" that allow different levels of exhuast gas into the intake this is all contrlloed by the on-board computer. There is a way to test the thing, however, it requires you to wire into the solenoids located on the valve.. in other words, it's a pain. I would suggest removing the valve, inspect the passages in the intake, and on the valve for carbon, clean with carb and choke cleaner and blow out with compressed air and replace the gaskets.

[Blue Bowtie]

A failing power brake booster can do that, too.

[59 agnj]

[I have already removed the EGR and cleaned it and the manifold ports , how about an ohm reference or volt reference , or another idea ?

[59 agnj]

my booster isn't leaking either , more ideas , please , thanks ?

[kingtut1980]

The resistance specs are as follows; Terminals A-D= 20-30 ohms
B-D= 20-30 ohms
a c C-D= 10-17 ohms
Term configuration; * b *
*
* d

[kingtut1980]

Well that didn't work. "a" is top left "c" is top right
"b" is the center terminal and "d" is the bottom terminal. hope this helps.

[Blue Bowtie]

You can try unplugging the O² sensor (it will set an error code eventually) and see if the problem still occurs once it's at temperature.

[59 agnj]

[unplugged O2 and still no change , any more ideas ,cause I am about ready to take it to an actual shop with a diagnostic computer ? I really despise newer autos with all their engine management bull**** .

[Blue Bowtie]

Check the rubber grommet on top of the TB. That is the point where the PCV and other vacuum lines connect at a "T" fitting. That grommet is notorious for disintegrating and causing a medium/large vacuum leak.