Ok i have a 1997 Chevy Express cut away van with a stock 6.5 turbo engine. When i am going up a long hill or when im passing someone on the highway and hit the gas it takes off then seems to fall on its face. i did get a engine code today that says check boost sensor range. not sure if the wastegate is sticking or something else as the sensor is new . its got 349789 miles on her. the injection pump and pdm with relocation kit last year new lift pump and pdm awhile ago and did the pdm relocation in a new spot because they relocated the pdm under the dash next and bolted it to the heater box.. any ideas ??

 

Lot of blacksmoke? Is it like its running out of fuel or just no sack?

 

no black smoke acts like its hit its rpm limit and will buck and kick once in a while. but only when im passing someone or pulling up hill

 

hmm, sounds like a lift pump or the sock in the tank could be dirty
if there is no black smoke your turbo should be working fine.

changed the fuel filter?
any fuel leaks?
check the fuel pressure
how rotted are the fuel lines?

 

Hello
Ok the lift pump is less than 2 months old i changed the Fuel/Water Separator filter last week when i did an oil change and service. Im getting between 15 to 17 psi on the fuel at idle and all the fuel lines were replaced last year when i replaced the injector pump and while i was doing that i replaced the fuel tank sending unit . there is a number 4 resistor in the Pdm . Have to say van runs great except when i pass someone

 

when i ran a #9 in my truck it ran like crap. i wonder if you try a different PMD

 

tried another pdm without resistor with a number 2 and a number 4 and does the same thing

 

Note the Boost sensor code... That's probably your issue, too much boost so something probably screwed up somewhere. Try another MAP sensor and see if it does anything.

I have been going through the tune on my truck and all the information within the computer. There is a couple second delay from the point that the computer picks up an overboost signal to the point where it cuts fuel but it WILL cut fuel if it senses too much boost. In english: either the wastegate is stuck (easy check, if you grab the wastegate actuator shaft, you should be able to move it fairly easily), boost controller is hosed, or a sensor is bad.

Option 2 is an electrical issue with the lift pump. My truck would run great until you put your foot into it, then it would stumble and buck for a while. New lift pump, new oil pressure sending unit, new relay, and it ran when the truck idled but the pump cut out while driving. There was a constant 12 volts but not enough amps to power the pump.
Jumper the pump to a good power source and see if your issue goes away.

 

truck is OBDII lift pump setup is different, if it throws an overboost code it will throw a check engine light and put truck in safe mode

 

try your oil pressure switch.I just put a new one in my 93 and i got all my power back with in a week,