My truck has recently started to stall between 30 and 40 mph and then started dying going down the road i can stop it and fire it right back up and it runs fine any suggestions on what it might be?
When it dies the fuel gauge stays were it wasand the check gages light comes on. Will a vaccum leak cause some of the stalling and it black smokes alot
Sorry, I meant a fuel PRESSURE gauge. If you suddenly loose pressure then it dies, you can chase the low pressure side of the system like plugging tank sock, etc.
Sounds electrical, Have you removed and cleaned all the grounds in the engine compartment? Especially the ones where the transmission dipstick mounts. Start with that because if you haven't done it yet you need to and at worst can cost $2 in new connector ends.
Do you have a spare pmd? If not you need one just as bad as a spare tire- it's just part of the 6.5 world. There is no way to test one other than putting in a known good one, and a defective one can cause all kinds of different problems including your current description.
Start with the basics. Check your oil, check your coolant level,
jumper your lift pump and run about 3/4 gallon out the T valve, Note how long it takes to pump 1/2 gallon.
Check your air filter.
On a 95 and older, do the dual lift pump relay upgrade or buy Leroys at leroydiesel.com
If your lift pump runs jumpered, check to see if it's running when the engine is running. Or jumper it and see if you have the same problem with the lift pump jumpered.
If you determine you have a bad OPS, check for voltage at the lift pump with the truck running. If you have voltage there it will be enough to trigger a relay. I just do the dual lift pump relay upgrade and skip the Oil Pressure Switch/OPS.
Vacuum leak can cause black smoke due to turbo inability to build pressure.
Vacuum leak WILL NOT cause any stalling.
Unless the truck have an EGR which may cause stalling if the intake is completely plugged dirty with exhaust soot.
That is more cause by the clogged than a leaky vacuum lines.
On a 95 or older, do the dual lift pump relay upgrade for sure. Either make your own with Buddy's schematic or order from leroydiesel.com. His is very nice plug and play. You might want to look at his and wire it the same if you make your own.
I definitely agree on the Relay set up from Leroy, but I would chase down the problem first. Adding or changing components can muddy the problems while trouble shooting.
What is happening with any of the gauges you have when it does it? Do you have any dtc's?
Let me clarify something- When I said sounds electrical, I am thinking along the lines of you are not getting fuel due to an electrical signal (or lack there of) telling the ip to send fuel to the injectors. Or a lift pump notable to keep up with demand and with a worn ip, it wont create enough suction to pull the fuel as well as it used to.
You could also have a fuel line or filter clogging.
As far as a dual relay option, it can be done with one. For customers that want prime in WTS I can add that to the single relay easily.
PeeWee sounds like classic sysmtoms of a failing PMD to me. If you get to the point you need another I have brand new Flight Systems on sale a $125 while they last.
I've never had to shut my vehicles off with failing PMD's. They did the shutting down just fine all on their own. Actually I never had much for symptoms other than dying like the key was turned off or run away. But they do have a wide variety of symptoms
It sounds like a fuel delivery issue to me. In that he runs down the road til it doesn't want to go. He shuts it off and restarts to good running again. Like when a fuel filter or sock sucks the gunk up and when you shut the truck off the crud falls away til you restart and it eventually sucks the crud back up again.
Maybe I misunderstood.
As we know, with these trucks it can be anything, just have to start the diagnostic process and go through step by step.