1996 Chevrolet Turbo Diesel 6.5 surges as if pressing accelerator in spirts

Question

My friend has a 1996 6.5 turbo diesel I'm trying to help him fix. While driving it, the engine surges as if I'm spiking the gas pedal, especially when I'm slowing down to a stop. then sometimes it will suddenly just shut off as if I turned the key off. I've recently changed the Pmd with a new vetilated fsd and relocated it with a fan on it. I've changed the ECM, Injector pump, turbo, fuel filter, lift pump, crankshaft sensor and wastegate solenoid, all within last six months. It's been running great until now. I also refueled and added diesel treatment this time. still no change. getting worse everyday. my friend said the engine lights been on almos since I changed the Ecm 2 months ago. Has a lot of codes and I know the definitions but can't tell what the actual problem is. P0216, P0236, P0251, P0380, P1214, P1218, P1656, P1216, P1635, PO117, P0182. Don't mean to overwhelm you. Any idea what could be wrong?

Answer 1

I just want everyone to know I found the problem and it was simple. The wiring harness for the optical sensor on the injector pump had an add on optical sensor filter and that is bad. I unplugged the os filter harness and plugged the sensor back in directly and it runs smooth as glass. Evidently that was causing the optical sensor to read incorrectly and thus causing the injector pump to miss, surge and stall and throw all kinds of injector pump codes. Hope this helps someone else. Took me a long time to find it.

Comments

i have a 98 chevy 6.5 td that is doing the same thing where is the opitcal sensor you mentioned located?

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the optical sensor is on the top of the injector pump right in the middle. It looks like a round black cylinder. it`s a very sensitive thing to take out and put back in just right. I've never tried it. the os filter that was the problem is an after thought bandaid for protecting against excess energy from the alternator I've been told. some people say it helped things and some say it's trash. for me it was fine until it went bad on us. the van is still running great by the way.