6.5 still stalls after new PMD w/heatsync

[Matt Bachand]

After about 6 months with my new FSD heatsync I am experiences problems once again.

I've checked my LP and it passes
Have good vacuum
Changed my filters

Is it possible that this could happen in 6 months? (6,000 miles)

It runs good in the morning, and right at the same time my t-stats open up the stalling begins. Now that it is really cold up here, problem is horrific, stalling every 20 feet. Eventually it gets past its crankyness, and runs no problems. The ride home could go anyway.

Sometime when it stalls, I can catch it by hitting the gas pedal a few times, othertimes I sit there for a few minutes before it can restart.

It stalled about 35 times in my 10 minute commute this morning. If I get free of traffic and floor it in 3rd (auto), it seemed to run, I jumped on the highway, and it stalled another 3 times before I got to my Job.

Need help bad.

[sschevelleman]

There are many reasons for stalling other then a failing PMD. I would only suspect the PMD as a possibility if you haven't been re-torqueing the PMD screws regularly. For heat transfer to take place, there must be 200psi of clamping pressure between PMD and Heat Sync, which equates to 23 in/lbs on the screws. If no torque wrench, use a 7/64th allen wrench and tighten extremely tight. They're grade 8 screws. If left loose, the PMD will overheat and may be damaged.

Check your DTC codes also and report what you find. If still in doubt, send us back the PMD for testing. We'll check it for you n/c. But with a PMD that new, a new PMD harness, good supply pressure, its most likely the injection pump.

[sixnickel]

Don't assume the problem is not the FSD. I have a '99 K1500 suburban with an FSD Cooler on it, the fsd was about 3 years old. It quit on my wife in traffic, she was able to get one more start out of it to get it off the road, then nothing. After I got the vehicle home, I messed around with it for about 2 hours checking everything. I didnt think it was the FSD 'cause it was on a cooler, I did have a used fsd, so out of desperation I plugged it in. Flipped right over and started. Its been on there ever since. So don't assume its not the fsd. And as Walt said in the other post, you have to keep checking the torque on the fsd mounting screws. Good luck.

Sixnickel

I have two 6.5s, a '99 Suburban with a BD computer, FSD cooler, and SS diesel air intake, and a '00 K3500 SRW with a heat sync and a SS diesel computer, exhaust and intake

[Matt Bachand]

Well I cleaned every ground I could find, replaced the two ribbon grounds
(engine to frame, and frame to dash) , re-tightenend my pmd screws (i got about a 1/4 turn outta each of them till really tight), and took it for a 20 mile test run. Didn't stall yet. We'll see how tomorrow brings. I try to tighten them every other month. I assume with cold weather coming in the heat bath they take will make them move a little more due to extremes. Lets see what tomorrow brings.

[Matt Bachand]

we'll lessoned learned the hard way


Make sure you guys re-tighten your pmd as Walt suggests in the instructions. I didn't realize how importanat this was and failed to do so.l Now my PMD stalls all the time. I went back to the factory one (bitch to re-hookup) and saving my pennies for a new one. Truck hasn't stalled since. Plowing has me scared I need a new one.