2.8 rodeo flat spot

[magicdeo]

Gday. I have a 97 2.8 rodeo and it seems over the last 2000kms or so i have developed a flat spot between 1500 and 2000 rpm. It was never there before and I can accelerate hard through this range without noticing it, only really when I drive through this range moderately. I am almost positive its not the injectors or injector pump. Anyone had a similar problem?

[magicdeo]

Surely someone has an idea? IP rebuilt about 5000kms ago? Injectors only 40 000kms old

[jellis]

Got a boost gauge?

[magicdeo]

Nah mate but i can hear the turbo always spooling

[stardog]

Had same kind of problem when I swapped engines in my MU and it was gutless turned the fuel delivery screw up a touch I have a boost gauge on mine could hear it spool up also but only 5psi boost until I done the fuel delivery screw now it its about 14psi.
1 more thing have you done a fuel filter change lately you could have some air in the fuel system or a bad filter just a thought.
Was the IP static timed properly with a dial gauge when it was installed as well.
Only other thing I could think of is fuel bug or slightly blocked fuel pick up filter in fuel tank.

[magicdeo]

Yeah I have changed the filter. If there was air in the system (providing there is no leak) wouldnt it be gone once the motor ran for a while or can it get trapped somewhere? It was timed with a dial in the back of the pump is that what you're asking? I am going to blow compressed air backwards down the inlet hose to the water trap to ensure the pick up is not blocked but if it was wouldnt it be starving for fuel all the time?

[stardog]

if you have done all of that I would think maybe there is a problem with your IP who rebuilt it for you .

[magicdeo]

It was built by a local diesel shop with a very good reputation. Its a strange problem, sometimes you will be driving along doing 100kph and the engine sort of hesitates, not exactly misses, a bit like hitting a gust of wind. Its a hard one too because problem is a bit intermittent which would suggest maybe injectors and pump are ok wouldnt it? Also it didn't happen until about 4000kms after the rebuild. I have a 296 CAV filter on it I dont know if anyone has had problems with them? I have tried another one exactly the same and the problem is still there

[geeves]

air leak in the fuel system could cause it

[magicdeo]

Hmmm might have to bring out the clear hose...