My 85 Camaro runs great, most of the time. 305 TPI V8, 191,000 miles, automatic. My problem is, every now and then, it starts running poorly. It can run great for a month, two months, and then one day, it becomes difficult to start, will start to backfire. Even when it is running good, on start up, it smells strongly of fuel. When I drive any distance, if I stop for a few minutes, it will not restart, until it sits for about 4 or 5 minutes. If I drive less than a mile or two and stop, no problems, but no farther or I'll have to wait.
I use this car daily, and this problem is driving me crazy. Does anyone have any suggestions on what could cause this? I've had this car 23 years, and this is the first time I have had a problem that I can't diagnose.

Thanks,
Paul

Welcome to Team Camaro....WOW 23 years, did you buy it brand new? That is a weird issue. The easiest and least costly thing to do is check it for fault codes. You don't want to start throwing parts like a Throttle Position Sensor, Coolant Temperature sensor, cold start injector and the like including an ECM which is known to have intermittent issues. Have someone put it on a scanner and pull trouble codes. On my 1984 Z28 which was carburated used to check codes with a paper clip from one terminal to another like my buddy's Dodge Daytona Shelby Turbo-Z.

You have alot of miles on the car. If the scanner reveals nothing you may possibly have an intermittent issue w/ the coil like I had on the 1969 Camaro I won now. I also replaced the MSD 6AL w/ a Digital 6 plus. Like I said you don't want to throw this or that at it unless you have money to throw away. Check it for fault codes and let us know what you find.

Thanks!!

SSG&H

I have a friend with a scanner. He put the car on it, but no codes came up.
Any other ideas?

Thank you,
Paul

If no codes came up speaking on my personal experience with these cars 15 years ago there may be an intermittent problem with the ignition module in your distributor or possibly the ECM itself. At that time back in the day I would interchange parts with other friends that were running GM HEI's in 1st, 2nd & 3rd gen Camaro's. Some would need the ignition module replaced, some the ignition coil in the distributor cap. And on rare occasions the pick up coil would need to be replaced which means the distribution would need to removed & re-installed. These things (ignition module, pickup coil, ignition coil and/or ECM) would not show up on a scanner if they go intermittently bad when hot.

Here's the part that really S*CK$---you could replace all these things and I've seen the "cold start injector" cause a problem like this. I've see the coolant temperature sensor and even a throttle position sensor. Or possibly spark plug wires that are arcing (bad wires).

I'm sorry I can't pin point it for you. It's been 14 years since I worked on a 3rd gen although I have looked at a couple of 1989 & 1990 5.7L IROC's lately as I want to buy one. I also don't want to tell you to blow hundreds of dollars in parts.

Try this link http://www.thirdgen.org/techboard/tech-general-engine/ Thirdgen.org is great!! I hang out there every once in a while and post there once in a blue moon (rarely). The guys over there work on their cars daily and may be able to pin-point it for you. I'm hoping it's an easy fix like an ignition coil or ignition module.

Check the IAC and replace the fuel vapor canister.