I have a bizzare problem. When I park my car after a drive (30mins to 1hr) and then try to leave again within 30mins or so the car starts fine and idles fine but then when I try to drive it acts like its running out of gas. Whats even weirder is that it'll clear out after a mile or so, and then run fine for how ever long I'm driving. I let it sit over night and then pressed the little schrader valve on the back of the engine and it sprayed alot so I know it's not losing fuel pressure when it sits.

I scanned the codes this weekend at the chevy dealership where my dad works when I replaced the trans mount and changed the oil. The codes it gave me were CPS fail (Whoever replaced the motor before me obviously didn't put the reluctor in!)which I always see, and EGR fail which is new to me. Then I got some codes dealing with the cats. Something like cat lean or cat slight restriction. The thing is that we ran the EGR test on the scan tool which will open and close the EGR valve by a percentage (10-100%) and it should have killed the engine but it didn't really have any effect on it.

My dad said that stuck EGR valves usually don't act like the problem I'm experiancing. He is trying to make me understand how to work on my own car because he says one day he won't be around and I'll need to save myself..lol

Do you guys have any idea as to what can be causing this odd condition? Feels like bad misses or running out of gas but then clears out. This makes problem number 30 with this car..lol anyone want to buy a 97z?

 

Slow night in here? LOL

 

Have you verified that all the components of the EGR system are in place? See reference photo from Shoebox:

http://shbox.com/1/egr1.jpg

What are the SPECIFIC numerical codes you got? There are a couple for EGR, CPS sensors, etc. Its almost impossible to help without the exact codes. For example, if you got the code for a faulty EGR vacuum solenoid, it would not permit the EGR system to work when you tried to cycle it with the Tech 2. If you got the code for low EGR flow, it might be an indication of low back pressure in the exhaust system, due to modifications to the exhaust. Need the code numbers.

Pressing the core in the Schrader valve may not tell you the fuul story on fuel pressure. You need to put a fuel pressure test gauge on it. Odd problems with restarts may be related to problems with the coolant temp sensor.

 

Typical of a vapor lock problem like I had with an 84 TransAM I bought new.

Do an experiment. The next time you get a chance to drive after sitting for 1/2 hour. Instead of simply taking off in the car, let it sit for 5 or 6 minutes idling before taking it for a drive.

I suggest you hook up a fuel pressure gage and tape it the windshield so you can see if it fluctuates when you have the problem.