98 2wd 2500 6.5ltd, ss marine injectors, pmd relocate #9 calibrator, intake and 4 inch straight pipe. ok so basically my truck has just started sputtering and stalling on me sometimes, i put a new fuel filter and lift pump in but she still does the same thing, theres a solid fuel current coming out the fuel bleeder valve, is it my injection pump startin to go? when shes not sputterin or stallin she seems to be runnin fine, she also has a harder start since this problem has started occuring, does anybody have any ideas on what thee problem might be?

 

I am only about 5 months into owning a 6.5L 97 Suburban K2500. After a fuel filter change started getting slightly harder starts and some smoke at start up. I changed to a new filter and bled the air from the fuel system (sounds like you did). That started about 6 weeks of weird symptoms from interstate acceleration bursts (slight increases in speed for very short durations) to hard starts to eventually no starts. I bought a used black standyne (spelling?) off of ebay and as soon as it was on everything was good. No more problems at . So I bought the 6 foot extension and a new PMD and relocated it this past weekend. All is well with the truck now and I carry two spare black PMDs in the truck if I need to swap out on the roadside. Check all your grounds - do a search for the ground connection points on a 6.5 that should be revisted and cleaned up and retightened.

Do you have a friend that you can borrow their PMD from to see if that fixes your problems? In my research I found that even brand new or just a few month old PMDs can go bad.

Good luck and stick with the forum they willl help you out!

~GOD BLESS~

john

 

ya im startin to think that too, when a pmd is bad, can it also randomly start acclereating your motor?

 

the intake mount location is the worst possible place to put a PMD NO MATTER WHAT SS DIESEL SAYS!

remote mount a NEW PMD outside the engine bay,behind/under the frt bumper or behind the grill on a rad support.

Many people and parts stores sell PMD's so you don't need to deal with SS for warranty that they will give you a hard time about.

Also if the IP harness ground was moved to the PMD heatsink to allow the harness to reach the intake mount location-put it back on top of the IP where it belongs.

 

I had issues with the motor surging while on the interstate and at speeds above 30 mph. I found in my research that it is not typically mentioned with a PMD going bad but a few did mention it. I do know that once I replaced the PMD it fixed the surging and the hard to no start problems.

Do you have any way to get ahold of a good used PMD to swap out and see?

~GOD BLESS~

john

 

ya i work at an auto wreckers and we have a 6.5 in the yard with the pmd relocated, so i grabbed the located one and it was even plugged it, the truck was still runnin on the one on the injection pump, so i tried that one and thats the one that would randomly accerlerate, so im guessin that one was shot too haha, but they both do 2 different things when i plug them in so thats why im pretty sure its the pmd, i just had it bolted to the upper intake so thats why im guessin she over heated

 

on a FSD heat sink and on the drivers side of the intake. It got cooked in only about 6 months based on when the seller told me it was replaced last. I moved it down to the front bumper with a 6' extension. Since you have tried two different PMDs and both exhibit issues I would go with trying to get another used black stayndne (spelling?) off of ebay. You can usually get one for under $70 with a 2 month warranty. That would be a great test for your truck before droppingg the $$ on a new PMD.

Some have reported that simply relocating the PMD out of the hot engine compartment can 'fix' some of the PMDs that exhibit problems. So you may want to research that.

~GOD BLESS~

john

 

A damaged PMD can NOT be healed with relocation.

When chasing drivability issues,I would not get a used PMD for diagnosis-they need to be proven reliable with a properly running engine first since most used PMD's are junk as well.
Used TESTED PMD's are a myth,they may work on an IP machine but not in the real world-the ONLY test for a PMD is to have it work on a real truck driving down the road.

If a vehicle already has running issues with starting,stalling ect. a NEW PMD is the only way to go for proving or disproving the PMD is at fault-it is much cheaper than an IP and what you have already found out is you will always need a reliable spare even if it doesn't solve your immediate problem.

 

A used PMD could just as easily be another bad PMD. A dmamged PMD most likely is damaged and gone - but I had read that a 'few' had luck with relocating ones that worked after out of the heat - I only had read that not experienced it myself.

I was just suggesting buying a used unit as a low cost option if he did not want to buy a new one. Too bad that the one used one he could try did not solve the problem.

~GOD BLESS~

john

 

Some used PMD's work just fine,but you have to have a good running truck beforehand to put one through it's paces and prove it good.

In my experience it takes 3 used PMD's to get a good 1,after the return shipping 2 times and the initial cost,it ends up being very few dollars between getting a good used PMD and a new 1.

If you shop around new PMD's can be found between $160-250 bucks and it is advertised that for about $360 Autozone offers a limited lifetime warranty PMD-should be the last PMD you ever have to pay for.

Do a search at Autozone for: FUEL PUMP DRIVER MODULE