Randomly dies?

[SL#189]

'86 GLH-t, A523 swap, MP Performace LM, A/C removed. no codes.

Occasionally while driving, the GLH will just die (sort-of) - no repeatable RPM or boost level, it varies. If I leave it in gear, it will not run, if I pull it out of gear, I can sometimes pump the gas a little to get it running again - but this is usually short-lived and it will die again shortly. If I pull it out of gear and switch off the ignition, and re-start it, it works great (although it sometimes takes 2-3 times for it to run right again) for the rest of the drive. On one specific trip, having the defrost on, no problems, but I don't know if it's related or just me hoping it's that simple (but I would still want to know why).

I have had a replacement coil suggested to me, but have not done it yet. I have considered possibly the TPS, I have replaced the SD relay, replaced the HEP, checked the shutter-wheel, replaced fuel pump.

Any other thoughts?

[moparfreak]

did you use an aftermarket HEP? i hear the aftermarket ones are garbage, find a used one, junk yard, or remanufactured and giv it a shot

[SL#189]

Definitely a Mopar HEP Learned my lesson with those aftermarket piles...

[PunKid]

the Coil could be getting hot and just needs a couple mins to cool back down.

I have one of those aftermarket HEPs in my 85, and every time it gets real hot it starts to sputter at idle and cruise until I run it at steady cruise long enough to cool back down. Very Annoying

[cordes]

Do you lose any electrical components when it dies? Radio, HVAC, etc.? How about the tach, does it just die?

[ScottD]

Have you checked the vacuum lines?

[SL#189]

Cordes - Electrical stays up (the radio never loses a beat), just a sudden, "quiet" (no jerking, shuddering) cut of engine power - it acts like a sudden cut of ignition.

ScottD - Just visually, although I should do a more thorough investigation.

[cordes]

I would check the wiring harness at the injectors. Also the grounds.

[ScottD]

+ 1 on checking grounds.

I've also had issues with fuel pumps where they weren't in the carrier correctly and that little hose that goes from the carrier to the pump comes off and causes problems.

Try to narrow down the stutter to losing fuel or spark and go from there.

[SL#189]

Thanks guys, I'll check those items this weekend and get back to you!

[SL#189]

Ran out of time to check anything this weekend - hopefully this week.

[RattFink]

Have you tried a new MAP sensor? I have a 99 Stratus that acted just like this. I know it's way newer, but still a speed/density system. Anyway, it had the exact same symptoms you described and I could never figure it out. One day it stalled out every mile and the CEL finally came on throwing a MAP sensor code.