Idle Problem

I need some direction. When I start my 90 camaro 350 TPI, it idles fine. When it gets warmed up it starts to idle up and down and dies unless I keep my foot on the gas. It showed a Code 32, EGR circuit. So I have removed the EGR valve and tested it, it appears to be good, it holds the vacuum. I cleaned it and put it back on, no more code, but it is still doing the same thing. I just replaced the distributor cap and rotor.All this started after swapping the transmission. What would be my next step? EGR Solenoid? Is there a way to test the solenoid? Thanks

Latest Update...I tried a new MAP sensor, IAC valve, and new plug wires with no luck.

Sounds like it might be a throttle position sensor (TPS). To test it use an analog ohm meter hooked to the sensor across pins A&B (disconnect the harness from the sensor). Now, watch the needle as you open and close the throttle. The needle should sweep across the scale in a smooth motion, no jumping around.

whatever it is, it's only happening in closed loop mode. I don't know if that helps narrow anything down though. IAC could be a possibility as well.

Have you run any fuel pressure tests?

The TPS and fuel will be my next check. Would a clogged fuel injector or filter cause the rough idle in closed loop? I also took the EGR solenoid off. It had a bunch of dirt caked on the coil so I cleaned what I could off, still no help. i also double checked all vacuum lines and found no leaks.

i don't think your egr has anything to do with your idle problem. how does it sound when you rev the rpm's up? is it smooth, or rough and choppy?

It seems to run a little better at higher RPMs but you can still tell it wants to run rough. I have gotten a intermitten SES code 32 light. Do you think there is a underlying problem?

It seems to run a little better at higher RPMs but you can still tell it wants to run rough. I have gotten a intermitten SES code 32 light. Do you think there is a underlying problem?

Well, the EGR could be the problem IF it is stuck wide open. It would cause a bad idle at that point.
If it isn't open all the time, the code 32 means that the MAP sensor isn't seeing a drop in pressure when EGR is being requested. that is how the ECM knows the EGR valve opened. If this is the case, the ECM will alter the spark map and may cause a lack of power and possibly a slightly rough idle (especially if you need a tune up). If the valve checked good, then check all of the hoses going to it. Check that the solenoid is working, then it is down to a possibly bad MAP sensor.

Could the O2 sensor cause a rough idle?

I would look at the map sensor like morley suggested first.

I installed a known good MAP sensor and it did the same thing. What else?

yea, i think you have a misfire.

what Geno said is a possibility. To check it start the car up when it is dark out and pop the hood. Look for any sparks down at the plug boots and at the distributor. Then check the wires themselves to be sure they aren't worn through somewhere.

when you swaped your transmission out, did you remove the distributor to make the top 2 trans bolts easier to remove, also you said you replaced the cap and wires, did you make sure there all in the right order?

i suggest removing the distributor when dropping the transmission.

After a lot of troubleshooting and a couple weeks later I found it to be the IAC valve and connector. Nobody carries a IAC valve for a 90 camaro 350 TPI. Can I take a IAC valve from a 90 corvette with the exact same motor and use the IAC valve from it?

i don't see why not, it's the same thing.

I went ahead and bought the IAC valve for the 90 corvette and put it in my camaro. It worked. The camaro had to learn how to idle again, but other than that everything is running good. Thanks for the help!!

sweet, glad to hear that

i have a 1994 camaro z28 thats having a similar idle problem, only mine is actually rough idling all the time. even at startup when it hasnt been ran since the day before. i'm not a very experienced mechanic but i'm trying to learn. all the symptoms sound just the same, if i take my foot off the gas, the car shuts of within a couple of seconds. anybody with any ideas would be greatly appreciated.

you might have an ignition problem.

Please start your own thread...It'll be easier to keep track of who is who and what we are talking about.

i have a 1994 camaro z28 thats having a similar idle problem, only mine is actually rough idling all the time. even at startup when it hasnt been ran since the day before. i'm not a very experienced mechanic but i'm trying to learn. all the symptoms sound just the same, if i take my foot off the gas, the car shuts of within a couple of seconds. anybody with any ideas would be greatly appreciated.