72 mph out of a 92 with a g360

[Crb12_89]

My stock 92 has 160,xxx 4x4 no muffler fuel pump turned up 1.5 turns will only go 72mph on a good day down a hill pedal on the floor does anybody know why????

[dazedandconfused]

Could be gearing but i bet your sucking the lift pump dry and starving it for fuel.

[Crb12_89]

How can I fix that w/o buyin a new one. Or is there no way to fix it

[Crb12_89]

It only turns about 18-2000 rpm when I've got iT floored and the turbo won't spool

[dazedandconfused]

Upgrade lift pumps. Which pump will determine use and power output of truck. Welcome by the way snd post up some pics of your truck.

[Crb12_89]

Thanks I'm trying but I'm new to this forum

[dazedandconfused]

Well have you checked the turbo? Does it blow black smoke heavy and never clear up? Could be a boost leak or junk turbo if its not spooling but my bet is going to be lift pimp. How does it run going threw the gears? Do you hit a spot and it noses over or is it a dog all the time?

[dazedandconfused]

Link in my sig shows how to post pics.

[RCCUMMINS89]

If turbo won't spool, might have a boost leak. do you have gauges?
At 2000rpms, you might not be getting full throttle travel.... also stock gov. spring only allows 2500. Do you have a tach to actually know your rpms?

[Crb12_89]

It runs good and stout it smokes but cleans up quick thanks again

[dazedandconfused]

Does it nose off hard when it stops pulling?

[ellis93]

My ol'truck wouldn't do 84 before the 3200 gov spring,that's with the 4.10's. Your running out of fuel plain and simple.

[Crb12_89]

No I don't have any gauges or a tach that's just a guess a guy that's a well known diesel mech. Around here also said. It might have a gov on it

[Crb12_89]

How bad is a bigger spring to put in and where can I find one. The truck is supposed to have 3.55s

[dazedandconfused]

My bet is your lift pump is toast. My truck with a weak lift pump, 27" tires and 3.55 gears will pull to 90 before hitting the governor wall on my stock pump. After about 80 it pulls real slow due to lack of lift pump pressure.