Need your help with some troubleshooting
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verified userI've got 93 GTI-R I've been driving year-round for the past 3+ years, mostly stock, except: Walbro 255 fuel pump, 8 (or 9?)mm plug wires, NGK plugs and just recently a custom 3" downpipe/ cat delete to a Jap cat-back with a SS muffler. I recently changed the alternator; the fuel filter, cap and rotor are all under 2 years/ 15000 Kms old. The boost is stock (no 1 bar loop, boost controller etc). In the last two weeks (starting out intermittently and becoming more regular and more severe) whenever I put the pedal down and get into full boost I'm getting some significant backfiring/ hesitation. If I'm 3/4 of the way into the pedal it accelerates fine, this only occurs when I'm into full boost. The backfiring / hesitating gets worse with more load/ higher gears: in 3rd gear, the car will actually stop accelerating, it'll just sit around 4500-5000 rpm backfiring, puffing out smoke and even once flashing flames out of the back of the muffler.
As I mentioned, for the last 3 years I have never had a problem like this, it's just recently come on. It started with just a "hiccup" every once in a while and has worsened to this point. Any ideas? Is this a MAF / TPS problem, or something more significant, like a blown turbo?
Any help would be appreciated. Thanks in advance.
Ty
All go, no show
pull some codes from the ecu, do a datalog, likely maf, wrong plug gap, bad knock sensor or overheated power transistor
Plug gap. Was >1.0 mm, squeezed them down to 0.8mm, no more hesitating or back-firing. Thanks for the info, Nick. Glad it was something I could easily check and fix myself. Cheers.
Ty
All go, no show
interesting....I've been having the same problem, but only when running my aftermarket ecu. It's been a nightmare to figure it out, as both tunes are the same, one just has a daughterboard.