Recently, my businses parter complained that his car kept stalling when stopping, and then take forever to restart.
I have noticed that his idle has also been a bit erratic, so after a quick google, it appeared that after a while, the throttle bodies get caked with crap, causing the engine to stall or/and an erratic idle.
The first step was to check the engine codes, on this car, its located on the left hand side of the glove box under the steering wheel:
After plugging in a code scanner, It read Fuel trim limit too high, and a couple of codes relating to the o2 sensor:
I cleared these and got to work.
Step 1, remove air box:
Step 2, Undo the 4 bolts and the electrical connector around the throttle body. This is what ours looked like before we started:
Step 3, remove the throttle cable and unlcip the electrical connector and Fuel vapour pipe:
Step 4, Thoroughly clean the inside of the throttle body with carb cleaner and no-lint cloths:
This is what ours looked like after cleaning:
Step 5, reattach the the electrical connectors and piping, and bolt it all back, including the air filter etc.
It has been said that throttle body adaptions should be run via Vag-com, but we did not do this. After this procedure was carried out, the idle is much more stable, and there is no more hunting, only time will tell however. If there are still issues, we will delve into vag-com to have a look.
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Thanks for this site you have been of so much help keep up the good work.on the other hand am having a problem with my VW polo.an EPC indication came on and my idle is not stable.at first i thought my throttle pedal was damaged so i swapped it but the problem is still on.with your help i cleaned the throttle body but the idle is still erratic.could the throttle body be faulty? please help
Hi there.
ITs possible, but the light being on means a code has been stored. Have you had a code reader or VAGCom onto the car to see what code/fault its logging?
Hi I have the same issue with my Polo Mk3 1996
it started after one day when I was accelerating a bit too hard I guess. Is it really necessary to remove the entire throttle metal thingy? can’t I just slide it open with some screwdriver and spray?
It is neccesary to remove it really, its a delicate mechanism and opening with a screwdriver is likely to damage it. Its really not too bad to get it off, 20 minutes tops.
Hey, Thank for the quick reply! The bolts around the Throttle body does a Phillips screwdriver works for them or regular screwdriver? How do I open those?
No worries! They are Hex/Allen key bolts, although it was such a while ago I cant rember the size.
Hi is it possible it is related to the spark plugs? If so, How would you check them in your polo to see if some have gone bad / need cleaning? or however it works.
Sorry one more thing I would love to ask.. My airbox does not have the tubing coming out of it to take colder air, How badly do you think this effects the engine performance?