Ok short boring story . . . When I had my car mapped I had the (forge) recirc valve shut off to get a flutter sound. Ever since the car has driven perfect although I was getting bored of the flutter so thought I would re-connect the Forge recirc. Now I can't remember what it was doing but it wasn't right so I took it off to look at and fitted the standard one back for the time being - functioned fine other than where it is weaker kept sounding off every lift off. So I spoke to Forge who kindly sent me a service kit for my recirc valve, I re-fitted it and seems to be working fine. However, now when I plant it and the boost hits above 1 bar I'm getting a boost stutter (cut whatever you want to call it), with the recirc connected or disconnected. It seems ok if you increase it slowly but not with hard accelerating, and it occurs more often in higher gears, 3rd upwards. Engine is running sweet other than that. Also there are no fault codes come up. Any ideas?? I read one previous post which described a similar issue and was resolved by changing the brake pedal switch. Any help much appreciated.
Does it stutter when you put your foot down from low revs say 2k rpm in fourth gear ? It could be a misfire perhaps.....
Ok I floored it this morning in 5th from about 2500rpm . . . accelerated fine until the boost hit 1.2 bar then it cut (and kept bouncing) like there was a rev (boost) limiter engaged . . . ??? Any help would be appreciated this is very annoying.
Sounds to me like it's getting an over boost signal and cutting it. Strange that there isn't a light on when it happens though
Definetely sounds like an overboost issue. Possibly a stuck wastegate actuator ? blocked/split/loose vacuum line ? Or maybe the map needs adjusting. I would take it to whoever mapped it or at least a specialist and see what they say.
Thanks for help guys . . . Yes indeed sounds like an over boost issue, but it was mapped by RS Tuning so I'm confident the map is spot on. I will investigate the other possibilities, to be honest think its prob a damaged/lose vacuum hose where we fitted the recirc. Is the wastegate actuator the one thats next (to the left) the recirc, I have the Forge uprated one? Closest specialist to me is Engine Dynamics just worried there gonna charge me a fortune investigating it /-:
Any chance I could of mistaken this for a misfire?? Garage reckon it could be this down to plugs/coils . . .
Yeah they are going that now as well . . . hopefully just a split hose or something. Andy what max boost pressure does Paul at RS Tuning normally limit the Meg's to? Mines similar set up to yours; 250 turbo, 630's, decat etc.
Ok so turns out engine had a misfire as well as over-boosting!!! Thankfully Andy @ Engine Dynamics diagnosed and fixed the problems . . . New set of plugs and boost pressure was leaking through the boost gauge, so this has been bypassed till I can plumb a new hose. Also recommended I buy a new set of coils but car is back to normal for now (-:
