I have a 1994 Golf 16V ABF and am getting an interesting hesitation. Is there something in the Digifant control system that changes between 2500 and 2800 rpm? ie. A switch from open loop to closed loop or a change in advance? Any time my engine accelerates between this rev range it sort of hesitates and bucks a little bit. Anything over or under this rev range works without issue. Thanks
I would start by checking the harness to throttle body round the back of the inlet, if its not been looked at by now it'll all be cracked up and shorting out most likely. make sure isv buzzes ignition on, one of the above wires shares the ignition live to isv so that pops fuse 15 for isv when that happens. the vacuum line to inlet or brake servo hose is worth a look, needs to be a meter long and if its braided hard to check condition of the hose underneath. https://www.clubgti.com/forums/inde...-0-16v-abf-throttle-close-microswitch.289567/ at this age the idle switches start to fail as well, mine started floating open and closed throttle off randomly which cause some interesting driving faults
I've noticed on bike there is a difference around 2500rpm, I believe it may be due to emissions related fuel mapping. Couple that with E5/E10 fuel and you could end up in lean misfire territory. My GTO Twin Turbo is the same at 2500 rpm, adding fuel in cured that completely.
I have rock solid idle when hot or cold. Throttle switches all test fine as well. ISV appears to be working normally but I will try to double check this weekend. As for the Vacuum line, I will take a look as well. It is definitely original so may just be time to swap. Any chance you know the I.D.?
Thanks for the suggestion. I only run 91+ that is ethanol free. (Canada) I am nearly positive that I cannot adjust the mapping on the stock ECU.
No I had an injector controller on the GTO (Emanage Ultimate). For the bikes, some you can put in "Race Map" via diagnostics. The others either put up with it or fit a Power Commander (modifies injector opening via programmable maps).
