Strike3

I have a 91, L98 coupe. I am having a crank but no start prolem. I can spray starting fluid and the engine will fire right up, until the starting fluid is all gone. Sometimes it continues to run, sort of. It sputters and backfires and usually dies pretty quick.nnIf it doesn.t die it occasionally will seem to smooth out and run right.

I think I have an intermittant loss of "enable fuel" signal from the CCM to the ECM.

Is the only fix a replacement CCM or can this be bypassed? Does it just provide a 5 volt signal to one of the pins of the ECM? Or something like that?

1963SS

I believe that the "enable fuel" is sent as a data stream over the serial bus (CCM to PCM) and is not just a 5 volt signal. If there is a problem with the fuel enable signal I think you should have a code 54 stored.

I would be sorely tempted to put a gauge on my fuel line and check my fuel pressures to verify you thoughts. Since the problem seems to be intermittent you may need to tape the fuel pressure gauge to your windshield and watch it as the problem occurs. Good Luck

stoydido

I see that you followed the thread by SEA4. He was lucky to find the problem without replacing the entire fuel and elec systems.

I would ohm the injectors, hot if possible. verify fuel pressure. a whole list of things before assuming that it is ccm or ecm. a rich condition might behave the same way. the starting fluid would overcome it.

the list is long, but start with some easy tests to get a clue, rather than speculating. if you follow these threads you will see many guys who "believed" if was this or the other and after replacing everything, they were still not running.

if it immediately followed fuel pump change, that cannot be ignored.

jc