i have a 97 z28 and the car will start up fine, it idles fine at first then when you put it in reverse or drive it almost dies, drive it and it runs to lean and misfires no power what so ever, then when you drive it for 5 min its runs great, almost perfect. then turn it off then turn it on and were back to horrible again. but sometimes it doesn't get better, it just stays horrible and it can barely get passed 50mph. vacuum leak? anything, its just very odd, im really confused. need help quick.

 

May want to check alot of things, fuel pressure and change fuel filter if its low. Is the SES light on? If so, need a scan for trouble codes, Opti could be going out. Air filter may be very dirty. Could be the ICM ( ignition control module ) . Dirty MAF ( mass air flow sensor ) For starters.

 

^^^ agree scann for codes, could be a number of things. how old is the opti?

 

brand new opti, spark pulgs and wires, pressure regulator, fuel filter, and mass air flow.

 

sorry gota ask. did you change these things because of the problem or has the problem developed after changing?

 

the opti, spark plugs and the wires were before. the mass air, the pressure regulator, and fuel filter and icm after the problem started.

 

check the plug wires for any damge. sometimes when the new ones go in they get up against the exhaust or get pinched. make sure you got the wires on the right plugs. what kind of plugs? i had some stock ac ones that lasted about a month. bosch lasted two or three months. ngk have not failed yet but im thinking they are not happy right now. lol. this thing runs rich and i havent had time to get it to a tuner. and every time i get bucks saved up i get something for the car. and what kind of opti?

 

I have taken that fuel pressure gauge and wiggled it up between the hood and windshield and drove the car to see if the pressure dropped while driving it, just to completly rule it out. Fuel pumps can be weak after running it a while just before going out all the way.

Here is z28pete's description of O2 sensor basics....

https://camaroforums.com/forum/computer-fuel-systems-25/o2-sensor-basics-17683/

Here is a O2 simalator.....

http://camaro.mantaproject.com/o2sim/

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just did the wires there Bosch, new spark plugs, new accel opti, new pcm.

 

i would suspect the opti. first take one of the plugs out and see if its fouled. mine were fouled bad and it would backfire at a steady 1700 to 2000. on exceration it worked fine. changed plugs and it stopped doing it. the plugs were fouled so i think the fuel was not being burned completely so the excess was igniting in the headers.