losing injector pulse

[boostedpb03]

Along with losing the pulse the temp and alternator light come on just before it dies. It idles fine,as you accelerate it loses pulse and thats when the lights come on and it dies,before it dies if you let of the accelerator it idles fine and the lights go out.No codes,scanner says ok to drive.
If anyone has any suggestions to the culprit or where to start would be greatly appreciated.the car is a 94 lesabre.

thanks.

[willwren]

The first place I'd look is the ICM connector below the coils. Your RPM signal goes in there, and the injector and spark signals go through it. Remove the connector (6mm?) and check for corrosion. Apply dielectric grease and reinstall it.

The ICM itself grounds through the bracket to the front cylinder head. I've seen this be a problem in the past. There is also at least 1 ground for the ICM harness that grounds to one of the bolts that hold the ICM bracket to the cylinder head. All these are potential issues.

Can you clarify how you know you're losing injector pulse, and is it all of them, or only one or two? If it's all of them, the injector drivers are in the PCM, but the ground point should be under your door sill plates or near the base of your A-pillar on the passenger side.

The PCM could also be an issue, as well as the ICM, but those are a bit more difficult to troubleshoot right now, and it seems your problem is intermittent, so let's ignore the expensive crap right now and try to narrow it down.

[Jrs3800]

I agree... The issues listed are not common of a 94-95 PCM failure... Like willwren has stated I would also like to see you check all of the grounds, the ones at the bottom of the passenger side A pillar are the ones I'd check first... Like stated check the grounds at the ICM as well...

[1fatcat]

A long time ago, I worked on a 95-98? chevy truck that had the exact same symptoms. Turned out the alternator was overcharging to a dangerous level (dangerous to the cars electrical system, not the passeners(15.5-15.9V?). The PCM had an over voltage fail safe for this build in and would kill injector pulse. That truck also turned on the batt and temp light when accelerating. It was odd because it would start and idle fine, even in gear, but as soon as you got the RPM just above idle, it would kill the fuel.

[willwren]

I'd buy that, but I'd want to dig into the FSM's to find out the failure mode for sure.