Club 80-90 Forums

Ok, so a little after having my bus terra cleaned/de coked, and new exhaust. it started running hi when idling, in a kind of random pattern. i cleaned out idle stabilizer. cleaned throttle housing checked for air leaks, now its a little better, but now a little ruff when starting and wants to conk out until some revs are given and when warm it occasionally, randomly drops or raises revs. i then changed the idle stabilizer and its made no difference . im now quizzing over the mas air flow unit. dose anyone have any idea what the screw adjustment should be on this. or any ideas at all on my problem. cheers in advance. Gradge.

there is an idle mixture screw on the afm................................but turn it at your peril.... try earths and connections and temp2 first. I found this when I was contemplating the same (see link below) and quickly talked myself out of it, but I did dismantle it from the air filter box and give it a good blast with contact cleaner, do you know anyone you could borrow a known good one from

http://www.thesamba.com/vw/forum/viewtopic.php?t=356377" onclick="window.open(this.href);return false;

mark

Thanks for the reply. Yes forgot, i did changed the temp sender too. lol. i think i will go round all the earths ect next to give them a good clean. i dont know of a known working afm although if this last attempt dosnt work i guess i will have to begrudgingly fork out the 100-160 quid for a second hand one.
maybe a slight problem..... i did bugger about a little with the afm screw, it seemed to make a difference to things !........ ok so smacked hands for that one and lessons learnt, Thats why,i was kind of looking for the correct ,you know, the old 8 turns out from fully closed kind of thing so at least i knew that was set correctly.
aw well on wards and upwards. cheers dude much appreciated.

gradge wrote:Ok, so a little after having my bus terra cleaned/de coked, and new exhaust. it started running hi when idling, in a kind of random pattern. i cleaned out idle stabilizer. cleaned throttle housing checked for air leaks, now its a little better, but now a little ruff when starting and wants to conk out until some revs are given and when warm it occasionally, randomly drops or raises revs. i then changed the idle stabilizer and its made no difference . im now quizzing over the mas air flow unit. dose anyone have any idea what the screw adjustment should be on this. or any ideas at all on my problem. cheers in advance. Gradge.

mine is a digijet system though, and yours is probably digifant is it? (so dont take the following as science)

Is it possible in that cleaning out the throttle body its allowed more air through? If the throttle switch is closed (telling the ecu youre at idle) and the revs are deemed 'too high', then the fuel is switched off momentarily, which creates a drop in revs (idle hunting). you can 'relatively' safely adjust the idle speed screw on the TB to turn it inwards to clamp down the air supply a bit. mine required one complete turn inwards to lower my revs enough to stop the ecu from tripping the injectors as above. easier if you have a rev gauge! (i dont, but have a multimeter with enough accuracy to do this job))

also make sure no extra air is getting into the throttle body thats not going through the afm intake. air leaks can cause some chaos, but sounds like youve chased any down already. some gaffer tape around the big jubilee clip sealing the afm to the tb boot made mine run a LOT smoother!

but as said, altering the AFM screw (little allen key) is another game, and really needs a rolling road and a sniffer thing to set properly, and i think only once the engine is warmed up... as youve seen, lots of afm info on the samba.

Im not an expert by a long shot, so someone else do step in if any of the above is not right, but just going from my experiences with it...