Hey guys. Im new here but thought this might be the place to find some help with my Camaro. Its a 93 Z28 with 126k miles has a new opti, fuel pump, ignition module, and coil, but however it runs for a while sometime 10 mins sometimes an hour and stalls out when this happens it looses both spark at the coil and fuel pressure. Let it sit for an hour or so and then it will start and run again. at the point im thinking its a pcm i just got the car friday all the parts were replaced by the previous owner in effort to fix this problem

thanks adam

 

You can scan a 93 for codes simply by shorting the pins in the ALDL connector. Shoebox has a how to, then you look the codes up in Shoebox's code list (93 codes are in the column on the far right, since they are different than 94/95).

http://shbox.com/1/dlc2.jpg

http://shbox.com/1/Dtcs.htm

There are codes that shut down the engine, but don't turn on the SES light. Could be as simple as a corroded short Opti harness. Or it may be the Opti..... which one did the previous owner install? The ebay cheapies from China are often faulty right out of the box, or fail in a few days or weeks.

 

Thanks. Well when it looses spark it looses fuel pressure. There are no codes, just the diag mode 12. The car smells like its runing rich. Idels at 450 550 rpms constant fluctuation. Alternator is charging 13-14v but is 0.75-0.90 v ac.

 

bump

 

Which trans? That determines stock idle speed programming.

 

I have had this problem in the past on a couple vehicles. One time it was the starter causing a short and one time the ignition switch was bad. Even the fuel pump can go out once in a while and once it cools some its back. Loose battery connections, ground wires not tight or clean can all cause problems. Basically saying there are so many things it can be, that tracking it down might be tough. If you had a spare pcm to try for free, that would be the best way to eliminate it. Comes down to doing one thing at a time and hope you find the free or cheap fix.

 

its an automatic