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Help please

UPDATE UPDATE . I got the new PMD today installed it and the truck no longer surges or sounds like it has a cam but it still high revs to exactly 2400 RPM. I can unplug the optical sensor and it idles down to 1000 RPM but anytime I press the accelerator and the rpms go up it still seems to struggle and choke
 
I'm afraid that I need to prepare $$$ for a new IP, because this main valve-dispenser lost its tightness. I had such a problem when I was 3 miles from home. I managed to get the pump to run smoothly by screwing in the solenoid ~1/4 turn. every thousand miles I twisted it. So I drove 3000 miles to home and then changed the pump.

I know that many will say that the solenoid cannot be turned. but when the pump is with one foot in a better world - then you can.
 
Will L. said:
Begin with OS/ CPS TEST recommend above.

Having a spare pmd for this type of diagnostics is a requirement for this rig. Like having a spare tire- you just need one. Some people just throw it in the glove box, imo a mistake.
Have the pmd on a heatsink mounted front bumper. Mount the spare on a second heat sink next to the one in use. Only buy a lifetime warranty pmd. Drive on it and use an old known good as the spare. Buy the premade or diy a plug with silicone to plug into the spare in order to keep the contacts clean.

NEVER hook one up without a heatsink. A second or two can burn a good new one up!

Why have it mounted ready to go? Because cold winter stormy night on the freeway is not when you want to have to mess with those 4 tiny screws. Swapping the plugs takes 5 seconds. Then you are on your way.

When the lifetime warranty one dies, swap to the other one. Then when you can, you send the warranty one in for replacement. Then put the new replacement back into use asap and keep the spare as the spare. Obviously if both are lifetime warranty- doesn’t matter which is in use and spare.

ANYTIME electrical is acting oddball, swap the connectors and you know instantly if it’s the pmd.

Removing and cleaning all the engine grounds needs to be a regular service task for these -really any GM rigs. I am a chevy guy, but GM electrical systems suck, and we have the worst grounding of any manufacturer. How often depends on your environment. I am in Vegas, 1930’s cars with original paint parked outside their whole life have no rust here. People in the rust belt should make it an annual task. A weak ground will send the whole system bonkers
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After one night that I wasn't dressed appropriately, & I had to swap plugs in the bumper holes. And I got yelled at by my wife for getting dirty, I bought an extra Made in the USA extension harness.

I run both harnesses up to the plug. Its much easier and faster to change there. The harnesses aren't all that expensive. 2 PMDs and 2 harnesses is the only way I will roll anymore.

The last time we had an issue we were getting a nice little bit of ice, sleet and snow. Not a time I want to be crawling on the ground.
 
denata said:
I'm afraid that I need to prepare $$$ for a new IP, because this main valve-dispenser lost its tightness. I had such a problem when I was 3 miles from home. I managed to get the pump to run smoothly by screwing in the solenoid ~1/4 turn. every thousand miles I twisted it. So I drove 3000 miles to home and then changed the pump.

I know that many will say that the solenoid cannot be turned. but when the pump is with one foot in a better world - then you can.
Click to expand...
can you not rebuild them ?
 
this will be an interesting thing to be able to rebuild our own IP's the last time I was at the junkyard there was a couple of gutted (intake's removed) 6.5's I found. looking at the engines they weren't worth pulling to rebuild. one had the intake ports on the head full of water :( both still had the IP's and lines intact and one still had the turbo. I would be willing to run out there sometime to attempt puling the IP's for a rebuild and have a spare ready.
 
$150 I guarantee is just a seal kit. Thats like putting on oilpan, timing cover and valve cover gaskets and saying you rebuilt the engine.

Even if you install all the new parts you can get - which the two most important is the head and rotor and they are nla- not running it on a bench for set up means you would be lucky to tet the engine running, let alone running good. Working at the dealership, they sent a couple of us to Stanandyne’s training class for them. Building a pump is like building an engine- some guys throw the parts together and make it work- but some are really good at what they do and understand the fine details make the difference in something that works and something that works really well. I rebuilt a few ds4, enough to know not to waste my time. I did a couple db2 and they were less headache but I still sent out my stuff to be done by someone way better at it than me.

Sure anyone can do it- but like building an engine or anything else that is very detailed- don’t do it yourself learning and expect great results the first time or two. In fact. if you diy- you better do a make shift bench tester to try setting up on- It can damage the engine if it goes really wrong.
 
I'm thinking there is an issue with the OS or the circuit for it. I know the truck is designed to run with one or the other in an emergency situation like limp mode. I've started mine before with the OS unplugged and it idled a little rough but good enough to drive a short distance. that was back when I found the noise filter was the issue. you might want to inspect the wiring around the IP real good for any shorts or breaks. even back to the FFM (fuel filter manager) the FFM wires are notorious for shorting out. there is also a ground wire that should be attached to one of the small screws on the top of the IP that is grounding for the IP harness and for the PMD. if anything in there is oil soaked. try cleaning with some brake cleaner spray. you can access that area better by removing the upper intake piece that connects to the turbo for inspection.

don't crank it up with the spray in the area though. you can run it without the upper intake but keep everything clear so not to get anything sucked into the engine.

post some pics of the engine in that area. maybe we can identify something to help. plus we all love some 6.5 porn lol
 
Any type of a fuel source , aerosol, natural gas, or even gasoline fumes can become a fuel source for a diesel engine, that makes for a great possibility to have a run away condition. Turning off the ignition key will do no good if that happens. The only way to shut it down is to suffocate the engine. A piece of board large enough to cover the intake is the only way to accomplish a shut down.
Do NOT use any portion of Your body to attempt shutting off the air supply. You will wind up with more than a damaged engine. As in a physically damaged body.
 
A Detroit instructor, giving our shop a class on the 8.3 Detroit V8 diesel.
He explained about the run away condition, the engine hemorrhaging out its internal components because it is revving so many RPMs.
He told of a mechanic that backed up to a run away engines intake system. Blocked the air supply with his buttocks.
He did not go into detail of what that must have done to that person, he just said that it did kill him.
Be very careful when working with these engines.
The fuel is coming out of that injection pump with enough force to blow diesel fuel through the skin. Do a google search on that condition. That might be enough to cause a NORMAL person to want to 🤮
 
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