yabbadoo4

iTrader: (8)

had my car remapped last year from andy f. made good power and very happy but my 02 sensor threads got ruined removing it to refit to my ported headers which were fitted on mapping day. no problem as andy can map without it as he uses his own sensor up the exhaust. before the car was mapped i had a coolant leak and had to remove the inlet manifold and loads of pipes etc to get to the pipe that was leaking but i noticed my mechanic had not piped all the vac hoses up correctly as my defi boost gauge was not working so i had a play around and managed to trace which pipe the boost gauge was teed off from. anyway fast forward a bit and ive replaced the 02 sensor and did a few logging runs and noticed the fuel trim readings were a bit off. it seems it thinks its running lean and adding fuel. the long term trims are at least +10 or 12. after doing some reading and googling around its suggested to idle and then raise the revs to 2k or 3k and see what happens with the long term trims. so i did so and sure enough the LT trims drop to zero. im led to believe that this would suggest there is a vacuum leak? would that be correct? the car does smell like its overfuelling and looking under the bonnet i have seen a pipe thats not connected anywhere but as yet cant find where it connects to. any thoughts would be helpful thanks.

yabbadoo4

iTrader: (8)

uppity......

bludgod

iTrader: (3)

what are your a/f correction values (should have a/f correctoin A/B/C/D in the logger). Normally I'd check them after around 50 miles mixed cruising/driving around to build up some nice averages.

if the car was mapped with a vac leak (sorry, I can't entirely follow you above as to when it was mapped and when you had/found/repaired leaks) then it will need adjusted again now the leak is fixed. The ECU will make some corrections off boost to try and wind things up nice, but on boost you could be very far out depending on what level of correctoin was made to the initial map.

yabbadoo4

iTrader: (8)

hi sorry for late reply. yes the car was mapped with the vac hose off. so i will still need to find where to plumb up the offending vac hose. i,ll contact andy f when its done. so im guessing the fuel trims will still read high as it was mapped with the vac leak even when i sort the plumbing out?

bludgod

iTrader: (3)

with the hose popped off you'll be sucking in extra air when the manifold is in vacuume but also losing air when the manifold is under pressure (when your on boost). The result is the maf scale on the car will be a little bit off from what it should be and you'll be a little leaner under boost and a little richer on cruise most likely. Once repaired I would try and drive the car off boost until the a/f's can be checked and adjusted.

That's worst case scenario though it depends how big of a leak it really was as to how much of an impact it's going to have on the fuelling.