*Skip to the end of this post for a TLDR version*

Okay, normally I loath to start a new thread since almost everything under the sun has already been diagnosed for these cars on here, but sometimes the specifics just don't add up.

So, here's the rundown: I have a '92 Camaro RS with the 5.0L V8 (L03). Most of the time it runs great with no problems. It's got as much power as a 23yo stock L03 should have, doesn't puff smoke, smell of gas, or anything. A very happy car. The problem arises when I run the car to OT (I drive 45min to work, for example) then shut it off and let it sit for about 20-40 min.

When I try to start it back up, it has all kinds of problems idling and running. Initially, I'll turn the key, the engine will start, then it will die almost immediately. Try it a few more times (sometimes allowing the fuel pump time to prime, sometimes just turning the key all the way) and eventually it will stay running, but with a very low and rough idle. Putting in my foot on the gas will kill it 50% of the time. If it doesn't die, the RPMs will climb but you can feel the car straining. At this point, half the time the RPMs will fail and slowly fall until the car again dies. If not, then I can hold the RPMs up for a few seconds and it will even out and go back to running and idling normally.

Here is the odd part: if I start the car back up less than 10min after I shut it off, it will start no problem. If I let it sit and cool for an hour or so, again, no problem. It's only when the engine has gotten hot, then given time to cool but not get cold. I've also noticed that the problem is worse the more humid it is outside.

It seems like the cylinders are flooding. The exhaust smells very rich and of unburned gas. I've never pulled a plug when it's having this problem (engines get really hot, guys), but they looked fine last time I pulled one a week ago and this problem has been around for much longer than a week (months or longer). The injectors seem to spray a nice cone and don't drip, either.

I've tried a few hopeful fixes, but nothing has worked so far.

TLDR:

• Car runs fine 90% of the time
• Trouble starting when engine gets hot, then given time to cool but not get cold
• Exhaust smells very rich but only when having trouble starting. Smells fine otherwise
• Once started, car runs normally again
• Average MPG is in the normal range
• Average power/acceleration
• even injector spray, no drip
• plugs are not fouled
• Fuel tank seems to hold pressure properly (healthy hiss if I remove the cap after shutting the car off)

Parts tested/replaced so far (not necessarily for this problem):

• MAP
• TPS
• IAC
• PCV
• Injectors
• Fuel Pressure Regulator
• In-line Fuel Filter
• Thermostat
• Coolant Temp. Sensor
• Manifold Air Temp. Sensor (NOT the Intake Air Temp. Sensor yet)
• Distributor cap + rotor
• Ignition coil
• Ignition Control Module
• Spark Plugs
• Spark Plug Wires
• Does no lose/burn oil
• Does not lose/burn coolant

I haven't checked the fuel pressure, but wouldn't that cause more problems at cold start than hot start? Also, it smells like it's getting too much gas and not the other way around. I plan on trying the intake air temp sensor, but besides that I'm kind of at a loss. Any suggestions for me?

 

Well I was going to say check your ignition control module, but it looks like you have replaced that recently. I would purchase an inline fuel pressure adapter so you can check your pressure also just to be absolutely sure you aren't having fuel pressure issues.

It wouldn't be a bad idea to your ignition control module tested either, especially if it is an "off" brand from a parts store (several testings in a row so they can get hot, one testing of the unit at a parts store will most likely do you no good, you want to unit to be how when it is tested.)


The pick up coil also comes to mind as a potential culprit of your issues. The pick up coil is inside your distributor, but I believe they can be tested by taking the distributor cap off. I do not know the exact testing procedure, so I can't help there. I do know that when pick up coils are going bad, they will cause starting issues like you described, and very frequently will also cause random stalling too. Pick up coils are cheap, but replacing them requires dissembling your distributor (shaft and all), so it's usually recommended to replace the whole distributor if you have to take it out anyways.


One more potential thing to do would be to try and read for any engine codes. Just need a paper clip with the ALDL port: http://www.obd-codes.com/faq/read-gm...codes-free.php

 

Alright, I had to make sure to come back and finish this thread.


After some tinkering and more trial and error, the culprits seemed to be a clogged PCV and some spark plugs that were worn just enough to give the engine trouble at startup.


I replaced the PCV when I originally made this post, and it seemed to work for a short time, but it was never perfect. Today I replaced the plugs and everything seems to be right again. We will see.


Thanks to Bubbajones_ya for the reply. The pick up coil will certainly be the next thing I look at is things still aren't working out.