Hi guys, Im posting on here on behalf of a friend who is pulling his hair out!
He has a very early turbo (93 I believe) which has just developed a strange fault.
The car is mechanically standard bar the air intake and exhaust and had been running ok for some time until its service last month.
When it came back it had developed almost a misfire when gunning it in all gears, at around 4500rpm the revs would disappear completely for a second then kick straight back in again. The ecu was changed for an sti version which although it pulled further up the rev range the problem was still there. The fuel pump was switched before the problem was finally diagnosed as a faulty FPR.
Having changed the FPR all is well in all gears except 1st. When accelerating gently its ok but on full throttle at 4500rpm again it loses all revs then kicks back in again. From 2 onwards is pulls really well and smoothly to 7000.
The ecu light hasnt come on at any stage and a code reader has been used on it just in case.
My friend suggested the plugs may be at fault but given that this problem is very specific as to when it occurs Id put money on the plugs being ok.
Apologies for such a long winded (and first) post, Im just hoping I can save the car from being sold (or torched!)
Any ideas?

Cheers
Andy

 

Your best bet is to pull out the coil packs, tug off the little rubber boot on them and look for any cracks. I was having the exact same thing going on for me and my coil packs were the culprit. Apparently the classic coil packs(especially the early ones) are notorious for cracking and sometimes breaking with old age. It's not to difficult a fix, it's just hard tracking down new coil packs sometimes. From the dealership they're quite pricey, but I got a second hand set that were only a year old for only 100 quid.

Also, does this happen in the rain or all the time?

 

Ah ok, not sure whether they've investigated that yet.
He did say it was a little jumpy this morning which was damp, but was drier and warmer when I saw it and the car had been running a while yet the problem still persisted.

 

I would go for coil packs as my first guess, hopefully he knows where they are and how to get to them, if not, I'm sure you'll be back and you'll get some help XD