lurching in 4th and 5th at WOT

[vxer]

Hi guys,

Got a weird problem with lurching acceleration in 4th and 5th only. Sometimes, when putting my foot down at about 50 or so in 4th, it feels like the second turbo is about to kick in, but then it doesn\'t and the car lurches. It\'ll do this maybe a couple of times in quick succession while i have my foot down.

Doesn\'t happen in 3rd or 2nd though, car pulls fine. Any ideas?  :confused:

Cheers, Paul.

[Fish]

Sounds like a fuel mix issue. Has the car been properly mapped?

Fish

[vxer]

Sounds like a fuel mix issue. Has the car been properly mapped?

Fish

No, its running a stock ECU... The seller said it had a striaght through exhaust on it, but when i took it to jimmys he said (after looking under the car briefly) that he thought it had a cat on it.

Guess i need to find out somehow...

Ta, Paul.

[chrisBoid]

I had this occassionally when I was running stock ECU but with de-cat mid-pipe, bigger back box and cold air induction.
Could have been an intercooler piping collapsing but I couldn\'t find any evidence of this (stress marks on the plastic hosing).  I thought the ECU was struggling to mix the a/f correctly due to my induction mod like Fish is alluding to.
Either way, the problem completely dissapeared when I had a PowerFC installed and mapped.

[vxer]

I had this occassionally when I was running stock ECU but with de-cat mid-pipe, bigger back box and cold air induction.
Could have been an intercooler piping collapsing but I couldn\'t find any evidence of this (stress marks on the plastic hosing).  I thought the ECU was struggling to mix the a/f correctly due to my induction mod like Fish is alluding to.
Either way, the problem completely dissapeared when I had a PowerFC installed and mapped.

Well, i guess thats a pretty good idea and another reason for me to get one!

Ta, Paul.