NewBeetle.org Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
My trusted VW mechanic has replaced the throttle body on my '01 2.0 four times now . The last was an aftermarket Bosch, but prior to that we tried used. The first replacement lasted a year before EPC light. Since then, less and less time between failures. Inconsistent and random performance from no power, no throttle response, to high revving. Becoming obvious the throttle body is not the culprit. What else could it be? 160k/miles and other wise runs great, just returned from a 1500/mile road trip, in Idaho and Montana the speed limit is 75mph and I still averaged 29.5 mpg with A.C. running most of the time!
 

·
Registered
Joined
·
120 Posts
for starters you say trusted vw mechanic. does this mean they have access to vcds. what code is the vehicle throwing. when the throttle body is being replaced is the throttle body then adapted with a proper scan tool such as vcds. when my throttle body acted up i simply cleaned it with electronic cleaner and carb cleaner. ran adaption and i was good to go. but if your mechanic isn't adapting the throttle body properly replacing the part endlessly will not fix the issue. if you have done all these steps i would look into the harness that plugs into the throttle body
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
He uses a cable that plugs in under the dash and connects to laptop. I havnt noticed if he plugs anything into the throttle body itself. The code are throttle related, though Im not looking at them now, same codes read at Autozone.
 

·
Registered
Joined
·
13,431 Posts
Please post any and all trouble codes, that you are getting. Do you have access to a scan tool and live data? Being able to read trouble codes and seeing the fuel trim levels, would really be helpful.

Fuel Trim Info - Ross-Tech Wiki

As noted above; you would definitely, want your throttle body to be aligned to start with.

https://www.youtube.com/watch?v=2zrmhDw_v7Y

video describing; vcds testing to diagnose your throttle body and typical problems with the vw throttle bodies:

https://www.youtube.com/watch?v=fdLA5pXUkk4

For performance and drivability related issues; I would also, test the fuel pressure and see if it is in spec.

service manual procedures; for testing (be sure to click "next" for more info):

Volkswagen Workshop Manuals > New Beetle GLS L4-2.0L (AVH) (2001) > Maintenance > Tune-up and Engine Performance Checks > Fuel Pressure > System Information > Specifications > Pressure, Vacuum and Temperature Specifications

Post up those codes and we will go from there.
 

·
member
Joined
·
431 Posts
Another thing to consider is the wiring harness. I have had a similar problem, but after cleaning it, the problem came right back after a few days. I soon discovered that by fiddling with the wires that go in to the throttle body it will work fine for several days, and when it starts again, I just do the same thing. Been doing that for over two years. One day I hope to change out the wires and throttle body, but this gets me by.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
codes from autozone today...
P0221 AND P0638

EPC light not on and no performance issues as of yesterday morning. Less than 1700 miles on new throttle body. As punchbug 77 mentioned, I do wonder about the harness/connection. This car runs perfect "most of the time". The exception being when EPC light turns on, and that is so random.

I have browsed the links provided by billymade... Thanks!! I will be making the VCDS investment soon.

I gotta believe that my mechanic is finishing the install with the alignment procedure, my guess is that it wouldnt run right AT ALL if not.

A huge thanks to all for interest and input!!
 
1 - 7 of 7 Posts
Top