I have a very sick truck, that I’ve trying to fix for the last 3 weeks.The truck runs strong in town.But once on the highway the truck shuts down at 70MPH.Today I removed the 3k governor springs and installed the stock ones.While cruising at at 70MPH the truck started to buck and totally shut down on the highway.It will restart with no problem,but the idle is low.Pressing on the throttle for a couple of mins,the idle gets back to normal.Heading back, the truck started doing it again.I decided to press the pedal to the floor to see if I could see any smoke.Nothing.But as soon as I pressed on the clutch to pull over, the engine revved to 3600 RPM.That’s when I shut the key off.Again it restarted with no problem,but had the low idle.I have replaced the LP pump and fuel lines.The shutoff value is working ok.Now the truck will not start hot,unless you give it slight throttle…Could the injection pump be on its way out???I still have to get a banjo nut to do a fuel pressure test…Thank guys…

 

sounds like a couple of things make sure your govenors are set right then your reving to 3600 sounds like you could have hung the rack open some how but check you timing thats what it sounds like to me if it white smokes and shutters when you rev it up i would re time it

 

Those pumps don't "go" out...

I'm guessing something went wrong with the GSK install...

Have you double checked EVERYTHING?

 

This heart break started, this winter ,pulling a little 6X 12 U-Haul up a steep hill.I took the hill at 60MPH,all was good..EGT was ok and boost was nornal.Since then,I have this problem.I installed the 3K springs about 12 months ago,with no problem.I installed the stock ones to see if this problem would go away...No luck on that one.Could the governor adjustment cause this problem??Thanks for the replys...This problem is driving me crazy.Being that I have to make a 1400 mile trip in 2 weeks...

 

Opps...The timing was set about two years ago to 15 degees..

 

It looks like Tate just got back into town. If you can check your fuel pressure that may help out on the fuel supply side. If the engine reved out, maybe there is some air in the lines? It doesn't miss until its at near 3K right?

 

I'm going to give Tate a call and pickup that fitting.I think he said its a 12MM fitting.Hope thats the size I need.The trucks starts to buck at 70MPH which is around 2500RPM.Yet this weekend,it did shut itself down at 60MPH,about 2200RPM.The fuel heater did have a slight air leak,so I removed it.Also replaced the rubber line between the LP and heater housing.When re-installing the governor springs,my measurements was 3.75MM and 3.54MM.What happens if the springs where set to loose or to tight??I know one guy who removed the nut off the springs and didn't take a measurement.No sure what he did...

 

My 2500 had the exact same problem while still under warranty. DC replaced the injection pump for free.
No more problem. Dealer told me this problem was somewhat common with '94&'95s.

 

Who did the springs Dave? Not taking measurements, not sure if it matters or not but its not uncommon to have different depths for each governor weight.

Bill, don't tell us that!!!

 

I did my own springs....I just remember a member posting once,that he didn't take measurments.. .When I removed the stock springs,I found that both side had different measurements..

 

Bill, does that mean there is a linkage problem internally?

 

The dealer who replaced mine couldn't tell me what exactly was wrong with the pump, just that they replaced a lot of them with my symptoms.
It was really a drag when it would act up, almost always on a hill with no place to pull over. It would go for a month without acting up then start doing it a bunch, then quit again. I wished it would just keep on doing it in order to pinpoint the problem. The dealer first replaced the lift pump but when that didn't help went straight to the IP.
Piers told me he had also heard of this problem but wasn't really sure what caused it.
I've often wondered if most of the bad '94-'95 IPs might have been replaced under warranty but that secondhand owners don't know about it.

 

A friend of mines 96 was doing the same thing when pulling a trailer and it was at the 70mph. The truck would buck like you said yours would do. Over time the problem kept getting worse to the point that 60 mph was all the truck would do and this was without towing. I follwed him and noticed a blue gray smoke. I replaced the fuel filter and this cured the problem. The filter was pretty dirty. This could be the problem or lift pump, overflow spring are all possible places. One more place that can cause fuel starvation is the fuel pre heater screeen.

Good Luck and let us know what you find.

 

I replaced the LP,checked and removed the pre-heater(Had a slight air leak)Going to order a overflow value...now...will see then..Thx

 

I ordered the overflow value.I really don't think this will solve my problem.But not knowing how old it is,I will replace.In the next couple of days I should have my pressure readings.As I searched the forums,I should have about 17 to 22PSI at idle and about 32PSI at 2500 RPM...Could a mis-adjusted governor arm cause this type of problem?