You may have read my previous threads about my MPi and it's constant poor running?
I recently changed the head gasket having identified an oil leak (with the help of John Guess) as coming from the corner of the head. This indeed turned out to be the case (back right hand side corner) and also into No.3 cylinder (from n/s end) which was a bit wet/oily/sooty (although the plugs never really indicated that) I also took the opportunity to change the Lambda sensor having had the car to Icklemini for plugging into his reader and identifying it as a possible problem (readings at tickover jumped about between 1 and 4 mV and on a run dropped an maintained 0mV, we also ran it disconnected which seemed to make the engine run better?).
Well after all this along with new plugs and leads (new set of iridium BKR7EIX's and today BPR6E's), new Air Temperature sensor and Camshaft sensor it still has the spluttering under steady acceleration!!! When I say "steady", it runs okay if very light and very heavy throttle used but anything in between casues it to hesitate/splutter as if it's getting starved of fuel?
It becomes worse once the engine is up to running temperature but ticks over no problem at around 850/900 rpm, saying that when ever you rev the engine it drops to around 1500 for about 2 or 3 seconds before it returns to normal 850/900.
Within the last 1500 miles (most of which was before I had it) it's had a new coil pack, wiring from ECU to coil pack, ECU removed and checked over, direct feed from battery through extra relay fitted to fuel pump (due to low volts identified [11.2v]) and injectors cleaned and new o rings.
Looking at a previous service (Dyno-Tune) report sypmtom is as follows..............."As engine warmns up, fueling leans off until hesitation occurs at all engine speeds, emmission measurements variable" The previous owner then spent over £850 on having it fixed from which the only change that improved things was the fuel pump direct feed through relay!!!
I am fast running out of money to replace anything else........HEEEELLLLLPPPP
PS - Southam Mini & Metro Centre had a quick look at it on their diagnostics machine and thought it was a fuel/air problem and to check for leaks - been all over it to no avail. They also suggested fitting a variable fuel regulator thinking it may be fuel pressure related? (is it 2 bar they run at?)
PPS - It has a Race Icon Chip fitted but have tried it with this linked out (thanks to Icklemini) and it made no difference at all?
Edited by nicksuth, 22 November 2008 - 11:14 PM.