Volkswagen Automobiles Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
87 Posts
i just put in a new engine into my mk3, before i removed the old engine it had the same problem, it sat at 2000rpm at idle, i was hopeing that it might be something to do with the headgasget being gone, but the new engine idles at 2000rmp aswell, i seen the engine that i bought running so im happy that its some sensor or something? not directly attached to the engine bcause i got the complete engine bar the throttle body, could it be the lambda sensor on the exhaust? any help is appriciated!!
 

·
'Black Balled' member
Joined
·
5,500 Posts
the throttle body, once 'disturbed or removed' or even if it has been cleaned with carb cleaner/brake cleaner needs to be 'set back up' to the ecu via vag.com.

Throttle bodies on these later AEX 1.4s are very sensitive; they are ' a sealed unit' of sorts (tho the TPS etc can be removed, they just wont work if bits are swopped from one throttle body to another) - its best up to look for a second hand one and try that- Id say that was the problem originally... they give an erratic idle

Its a bit of pot luck if you get one 2nd hand that it will 'work properley' after being set up to the ECU; I had 2 of them 'spare' when I had one of these cars; I later broke the car, and a member on here was looking for a replacement trottle body; i gave him the two for the price of one; only 1 worked as it should he later told me; these were both scrapyard buys...
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #7 ·
Thank-you Blzeedub, have a update on this, today i flushed out the coolent system and swapped the Engine temprature sender with another one i had from another engine, filled the system up again with new coolent and now it idles at 1200rpm
its a start but still high, so i dont really know my golfs but when i went to the breakers yard to pick up the engine i noticed a weird looking valve on the drivers side strut tower, the "Bosch purge valve" it stuck out so much because i know i didnt have one on my car, but looking at the car today there is a plug and a hanger that it would sit on if it was there. so the vac line that this valve is on goes from the charcole canister behind the front bumper to the throttle body, and if i disconnected the line from the throttle body the cars revs starts to climb, do you think my high idle could be caused by the missing purge valve? suppose its a start before getting someone to set up the throttle body on vagcom?
 

·
Registered
Joined
·
87 Posts
Discussion Starter · #8 ·
just playing around today with the vac line from the charcoal canister to the throttle body, i got a small G-clamp and lightly squeezed the Vac line to restrict the air flow and sure enough the revs dropped to 700-800rpm
, should i get the purge valve and fit it and see if it makes any diffrence? would it cause a little restriction in the line that might drop the revs, and dose anyone know why would this have been removed??
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top