Fuel or boost cut underload problem

[Gzzmos]

Hi guys
been doing a lot of reading and been going over the forums.

My brothers 98 patrol RD28 turbo has had many problems, which i've almost sorted out apart from this fuel/boost cut.
1st & 2nd gear is fine. but after there it hits some sort of a cut. and backs off from 11psi to about 6psi and wont go up a hill.

I just installed a new AFM, fixed a leaking fuel pump, boost leak and reset the ECU.
Also put a new fuel filter in.(coud it be air or water in it?) and new air filter installed too

I can move the EGR when i suck on it and the butterfly is moving in the intercooler. (thou it runs better when i remove it)

So any ideas? as i dont know where to go now...

Thanks

Nic

[threedogs]

Welcome buddy, you'll get a better response if you post your question in the right area,
plenty of info here and a great bunch of people as well, Enjoy



My Bad, jump over to the intros tell us a bit about yourself

[Gzzmos]

where do you suggest i put this?
thanks

[Gzzmos]

Just had another drive of it and noticed it does a slow creep to 12-13psi then drops off like a "soft cut"
Going to nissan tomorrow to plug it into consult and see what is going on

[threedogs]

Are all the vacuum hoses and fuel lines in good nic, and connected correctly

[Gzzmos]

From what i can see they are. i can see at one point the pump has been played with as i had to fix a leak (as someone didn't tighten the feeds up enough)

Also Someone has blocked the EGR valve but hadn't done the throttle part. (which i just did yesterday)

[Gzzmos]

Just an update.
Nissan didnt find any codes on the ECU. but sent me down the road to another place and he wants $300 to diagnose the issue. but he did say it isnt the fuel pump...

I just might take the TPS off and give it a clean. I swe somewhere once that it could be and issue?

[RD28T]

Just an update.
Nissan didnt find any codes on the ECU. but sent me down the road to another place and he wants $300 to diagnose the issue. but he did say it isnt the fuel pump...

I just might take the TPS off and give it a clean. I swe somewhere once that it could be and issue?

hey mate let us know what the issue turns out to be, im having the same issue with my 98 gu 2.8, been told it may be a faulty MAF sensor?

[Gzzmos]

Im trying to book in somewhere now to find out the trouble. Im thinking of trying a fuel cut defender to see if my new AFM is causing the issue.

[Gzzmos]

sorry for digging up my old thread but i just sorted the issue out. turns out the afm was reading too much underload. so i tried the Jaycar fuel cut defender and its seems to of sorted it all out.