Engine/Transmission (1998.5 - 2002) Engine cuts out on highway

[TBrill]

I have a 99 3500 Dually that runs great from an idle to about 55mph, but at 55-70 the engine will cut out as if you just took your foot off the gas pedal. The strange part to me is it won't do it all the time, I have gone 300 miles without an issue and other times it will cut out over and over in 50 miles. The engine never dies, it still runs just no power. It seems like it might be heat related, because if I pull over for a while it won't do it right away. If I put the truck in neutral when it does it and rev the engine a few times most of the time it will recover. When it does it, it does not throw any engine codes. My lift pump was replaced a couple of years ago, but I suspect it might be my issue.



Please help.



Thank you

 

[FourBarR]

If you do not have a fuel pressure gauge you need to get the pressure checked. One of the most important things you can do for these trucks is tomonitor the fuel pressure. If you loose fuel pressure you will toast the vp-44 injection pump.

 

[TBrill]

Unfortunately I don't have a fuel pressure gauge yet, hopefully I have'nt done any damage to the vp-44. Also the truck has 145,000 on it.

 

[BDahm]

Mine did the EXACT same thing, vp44 went south. Drove it like that for 2 years, couldnt go on the freeway beacause it would do that, progressively got worse. Changed the pump, no problem. You do need to verify the LP pressure,like everyone will tell you if the LP has low pressure the VP44 is most likely bad too.

 

[TBrill]

I thought maybe the VP44 was bad, I was just hoping that it was just the lift pump. I bought a FASS lp and will be putting it on this weekend, we will see.