Hello there, I'm new to this forum, and Camaros...I've done a search, but I can't find a lot on the subject.
I have a 1990 RS Camaro with the 5.0 305 TBI setup, auto tranny. I got the car about 4 months ago, and it's had a few problems.
First, we replaced the distributor, cap/rotor, & plug wires (long story short the distributor melted down...).
Once we did that, it ran ok, but was short on power & started detonating really badly (bad timing job...).

Now here's my problem. About 2 weeks ago the rpm's started surging pretty badly. It normally idles about 750rpm. In park (or neutral) the rpms will go up to about 2100. Stopped in gear, it sits about 1200-1500, and it's pretty hard to stop - it's like I have the gas on, but I really don't. That will happen anywhere from 2 seconds to 5 minutes, then it will drop back to normal. In the process, it will occassionally stall & die.
We checked the EGR & the PCV, re-set the timing & replaced the aircleaner. My check-engine light has not come on, so I am assuming that it isn't storing trouble codes (correct me if I'm wrong).
My gas mileage dropped considerably (by about 5mpg).
When I start the car up, it leaves black crud where the tailpipes are (been like that for a while...). My guess is it's oil, since the car burns about a quart every week or two.

This weekend I'm going to check the plugs and make sure they're gapped properly, and aren't fouled...any other suggestions would be great.

Also, my tranny has slipping issues & shifts REALLY hard in first & second gear. I think it might be due to the cable running from the throttle to the tranny - it's pretty screwed up. Is that possible?

Thank you guys in advance...

 

try cleanin egr

 

a surging idle in gear can be caused by many diff things so it is very elusive to fix try these:
1) correct spark advance
2) no ignition problems (good plugs, wires and distributor)
3) no big vacuum leaks
4) good IAC
Now to do:
1) turn on ignition and wait 5 sec.
2) disconnect IAC plug
3) run the engine
4) shut off engine
5) connect IAC
6) disconnect negative battery cable to reset ECM
7) connect battery
8) run engine
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The Iac (idle air control valve) is located on the passenger side of the TB angled towards the back of the car it has a black connector that is square
un plug the connector and using a square jawed wrench unscew the IAC i recommend using a tooth brush to clean the cone the spring and the shaft (DO NOT USE SOLVENTS OF ANY KIND) make it clean though then get a can of carb cleaner and spray it into the hole you removed the IAC from get that nice and clean again use the tooth brush let it dry screw the Iac back in and then continue with step 3

(by the way make sure to put the tooth brush back where you found it so a family member can brush his or her teeth)

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if it is none of that then it is everybodys favorite new scapegoat CTS

 

clean the iac, egr and look for vacuum leaks. Sounds like you forgot to plug something in when changing the air cleaner.

 

Thanks guys, I'll be working on my car this weekend. I'll keep you posted.

As for the aircleaner...this problem was there before that.
I found an unplugged two pin connector ...but for the life of me, I can't figure out what it goes to. Anyone have any ideas??

 

Looks like it is the connector for the IAT sensor, on the bottom of the air cleaner.

 

Holy cow, what do you know. It does plug into the bottom of the aircleaner...that thing must have been unplugged for a while!
I just plugged it back in and ran the car for 15 minutes...no surging or dying...I will drive it around today and see if that was the problem.

Oh, and I cleaned the IAC as well. It was pretty dirty.

Thanks again!

 

I've driven the car for a week, and so far the problem is fixed.
Thank you guys for your expertise!