Misfiring At Low Revs?

[jeffworld2]

hi, my rb25 was hesitating/sometimes missing around load point 13-14 at 2.5, then again at about 3 and again at 3.5 (approx).

I changed spark plugs taking out a set of 2-3 k km old bcpr6e and putting in some bkr6's, and the problem was still there. i already have splitfires, so i thought it must be the tune on the powerfc. After installing the stock ecu back in, it was initially almost fine, ie not revving smooth but not missing completely, so i put this down to the stock ecu not being close enough for my optimal tune. it has since developed the same miss on the stock ecu too. makes it very hard to drive and will hesitate or miss even on low load. light load is fine, backing off is fine. have tried lots of combinations of the two plug types and the ecu's, but none fix the issue.

car is stock turbo, full exhaust, front mount..etc.

Edited June 17, 2007 by jeffworld2

[NYTSKY]

If it s only been happening after your adventures with the plenum,i would say leaking inlet manifold?

[sicrb25]

Yeah could be your plenum leaking or a dodgy vacume lead, AAC?

Edited June 11, 2007 by sicrb25

[jeffworld2]

it was the catalyst for pulling everything apart anyway, and is continuing since. i think i will try a new fuel filter, as the pump takes a full 10 seconds longer to prime the lines before starting, this is suggesting i have a flow problem?

pump is a bosch 040

[jeffworld2]

problem found.. fuel hose between pump and the bracket had disintegrated, replacing with new, all should be good. thats why i wasnt getting any fuel despite pump running. just chasing a new fuel resistant efi hose and that should be that