Slight stumble at idle, jumpy and crappy at lower RPM's and when steady at 1500ish... if I punch it, it'll hesitate the go ***** out and run good... if I'm cruising on the highway at 2000 RPM, it runs good.

So... it got scanned and showed 6 and 8 injectors were bad... so I had them rebuilt. But before that, we changed the oil and filter and it cleared up for a day or two, ran like a dream... have no clue why? Put in rebuilt 6 and 8 injectors, fuel filter and it ran better, but not perfect.... he scanned it again, couldn't figure it out.

We swapped the ECM with a unit he had that had been pulled from another truck... it had a 100hp reflash done to it.... bam the truck ran like ****... it spun 36 inch tires on dry pavement and chirped them going into second... big smiles on my face. My truck ran like a dream for another day.... and has progressively gotten worse since.

I'm thinking I may have a harness/wiring prob... maybe air leak in the fuel system... hpop.... I've been researching and not sure what to think....

I've been running Power Service in every tank, it seems to run extra crappy if it goes below a 1/4 tank...
Tons of info guys I know.... maybe somebody has a clue... one thing I know absolutely... It's not the spark plugs... haha

 

The symptoms sound like a fueling issue, I would check if you do have an air leak between the tank and pump, not sure how its done on a PSD but I'm sure someone will chime in.

 

there is a wireing harness under neath the valve cover, Injector wiring harness, they have a bad habit of working there way loose...there is a write up around here on it somewhere ill try to find it for ya...

 

thanks for the quick replies guys... how to test for air leaks? as far as the harness under the valve cover... someone with an ohm meter and who has a clue about electrical I guess.

 

your idm could be going.

 

All I can say is what came about with the issue??