93 lumina cranks/no start-computer throwing weird codes

[wyley187]

I have a 93 lumina that cranks but no start, checked spark and fuel both good,just for laughs tried carb cleaner in intake nothing. car died suddenly while accelerating and hasn't started since, took to local mechanic and he thought possible computer problem switched out computer with new one and still getting 11 hard fault codes also I should mention that the new computer didn't take out the old fault codes when he reprogrammed it, I am at my wits end, thinking a possible short somewhere?? does anyone have any ideas on this?? thanks!

[Blue Bowtie]

What are the error code numbers?

[richtazz]

First, there is no "reprogramming" of the ECM in your car. All the vehicle specific info is stored on the E-Prom. The E-prom would need to be switched from your old ECM to the new unit, or a new E-prom calibrated for your car's specific engine/trans/emission info would have to be purchased from a dealer. If he installed a used ECM, and didn't switch the E-prom, there's the biggest issue. As Blue Bowtie asked, what codes is it indicating, and are they all the same as before? Since your ECM is mounted under the hood, it's possible the wiring harness(es) are corroded and not making a connection or shorting out.

[wyley187]

well thanks for the replies, some of the things that come up are that the tranny temp is at-20 degrees , something about gear switch diagnosis and I don't remember the other ones, maybe I should have been more clear in my description about the computer. This is exactly what the invoice says "also tried a computer and that did not take any of the old codes out when I reprogrammed it"

[richtazz]

unless your car is a california emissions vehicle (has RPO code NB2 in options list on SPID label), he's giving you crap, as there is no "reprogramming" possible on your car's ECM. If he charged you for "reprogramming", he's ripping you off. On an OBD-I equipped car, disconnecting the battery for 5 minutes or so will erase all codes stored. If the codes are immediately there again, it must be due to one of 3 things:

A bad/wrong replacement ECM
The wrong E-prom is installed
The wiring to the ECM is shorted/open/corroded.

Get me the last 8-digits of this car's VIN# (send it to me in a private message, you don't want personal info in open forums) and I can tell you what ECM # this car should have, as well as the E-Prom number/calibration code it should have.

[richtazz]

For anyone else following this thread, his car is a 3.4 DOHC. I gave him the proper ECM and E-prom numbers so he could double check. Neither of these are interchangeable with ones from a 3.1 equipped car, but are the same as the 91-93 Cutlass Supreme and Grand Prix similarly equipped. Finally, his car doesn't have California emissions. If anyone else more familiar with the 3.4 DOHC has any other suggestions, feel free to chime in.

[Manny_boy]

Has the timing belt been checked?