Hi, I have a 1990 Camaro 305 LO3 and I have a problem of some sort. Ok so when its cold it will start hesitating until it warms up a little. Next it gets **** poor gas mileage city driving or highway, I havent done the math to see what my MPG yet but I will. And third when I go above 50-55 MPH my check engine light comes on and stays on until I turn the car off then the light turns off. I have a new O2 sensor, new plugs, new cap and rotor, and no cat. What might be the problem, any help would be great!!

 

Pull codes while the CEL is lit...
or
take it to someone who can/will.

 

check vacume line to EGR vavle. how many miles are on it? the TB gasket mayve gotten sucked in somewhat

 

Pull codes. All you need is a paperclip and read: https://www.thirdgen.org/service-eng...ht-error-codes

Change fuel filter if you haven't done it in the last 2 years.

 

It has almost 130,000 miles on it. The fuel filter has been changed about 1 year ago or so. I will try to get the CEL read this weekend or asap. I will write back once I get the code.

 

im going to guess you have a bad coolant temperature sensor. and the code is going to be an egr problem.

 

My car had near the same issues. Sound like a fuel pump issue. Get a Fuel pressure gauge and hook it up during idle. If i recall correctly it should be between 9-12 PSI. If its not then change the filter and recheck. If its still off then may want to change the pump.

 

Well today I replaced the Coolant Temp Sensor and it wasnt the problem. So my next try is finding someone who can read my CEL. Hopefully asap!

 

I left the link to read the codes above in post 4 - all you need is a paperclip ... really.