Help! fresh ideas needed...

[1781cc]

hi peeps,

Having an issue with the running of my car that I cant seen to solve and its really doing my head in... car seems to idle fine when starting up but as soon as its warm after a quick drive the idle moves between 700rpm and 1300rpm all by itself, at a continual, regular cycle.

So, I thought it was my throttle body, I cleaned it and did a throttle adjustment using VCDS, made no difference, checked for air leaks, couldnt find any... checked for a boost leak, couldn't find any... disconnected the MAF, makes no difference to the idle.

Needless to say when its running, its not making full power and feels sluggish.

I replaced the throttle body, and the hose that runs from the top of the dump valve to the inlet as it was looking scruffy and there could have been a hole in it, no difference...

I am guessing the hunting is down to an air leak, but I just can't find it!

ORIGINAL ERRORS AND LOG BEFORE CHANGING THROTTLE BODY

Saturday, 13 October 2012, 09:02:58:4907
VCDS-Lite Version: Release 1.1
Control Module Part Number: 8D0 907 557 T
Component and/or Version: 1.8L R4/5VT MOTR HS D06
Software Coding: 04001
Work Shop Code: WSC 00000
VCID: 41F5D52C5887

4 Faults Found:

18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-00 - -

01165 - Throttle Body Control Module (J338)
17-10 - Control Difference - Intermittent

00670 - Throttle Position Sensor (G127)
06-10 - Signal too High - Intermittent

17953 - Throttle Valve Controller: Malfunction
P1545 - 35-10 - - - Intermittent

---------------------------------------------------------------------------

ERRORS AND LOG AFTER CHANGING THROTTLE BODY

Monday, 15 October 2012, 10:14:40:4907
VCDS-Lite Version: Release 1.1
Control Module Part Number: 8D0 907 557 T
Component and/or Version: 1.8L R4/5VT MOTR HS D06
Software Coding: 04001
Work Shop Code: WSC 00000
VCID: 41F5D52C5887

2 Faults Found:

01165 - Throttle Body Control Module (J338)
17-10 - Control Difference - Intermittent

17953 - Throttle Valve Controller: Malfunction
P1545 - 35-10 - - - Intermittent
---------------------------------------------------------------------------

[benntenn67]

An inlet manifold gasket leak or maybe the ISV ??

[1781cc]

hi mate,

My car apparently doesnt have an ISV? I checked all the gaskets - looks fine to me... any other ideas? lol

http://www.passatworld.com/forums/42-volkswagen-passat-b5-discussion/316676-does-my-car-have-idle-stabilization-valve.html

[benntenn67]

Another thing to try is all the vacuum lines, esp the braided rubber type ones - these tend to fail at the ends ??

[1781cc]

will try all those again - its really annoying, the braided one that runs from the dump valve has been done, it was a mess, but still got the problem, might try and replace all the vacum hoses throughout with silicon ones. I have a pile in the garage from my prelude days.

bloody car!

[chiefmechanic]

Kamei

Hi lee, sent you a pm about the kamei rear spoiler. Brian

[Pirvu Eugen]

Check the voltage at the throttle motor....i think is the voltage problem...ignition switch or main fuse relay panel plugs...(poor connection somewhere)
Hope this helps!

[Greg_S]

Either a voltage issue or idle stabilser valve i reckon

[1781cc]

thanks for the voltage pointers guys - will look into that today!

[1781cc]

working away at the moment so progress has stalled, but that said, I am having issues still with the idle and running of the car.

http://www.youtube.com/watch?v=J5sCViQVr9I

so far I have replaced:

- throttle body
- several air hoses
- lambda sensor
- coolant temperature sensor
- diverter valve
- replaced several breather system components
- throttle gasket

I still have the following errors on VCDS:

01165 - Throttle Body Control Module (J338)
17-10 - Control Difference - Intermittent

00670 - Throttle Position Sensor (G127)
06-10 - Signal too High - Intermittent

17953 - Throttle Valve Controller: Malfunction
P1545 - 35-10 - - - Intermittent

Voltage at the throttle body is apparently fine, and this AEB engine doesn't have an ISV - oh, and adaptations don't fix the problem...

Any ideas?

[bikerjim]

I would try a known working MAF if I were you. Failing that try another throttle body.

[will20v]

its quite often a split breather hose under the inlet or a broken hidden one way valve. ive seen people scrap there cars because they cant solve it lol

[1781cc]

I have 2 working MAFs and neither solve the problem, so much so when you disconnect the MAF it has no effect on it, its not a boost leak.

I will have to spend a day on it and just unscrew and screw everything on it. Might get a new PCV valve to start with though...

[Jenks]

May be wrong but that might just mean you've got two knackered MAFs there. Have you tried either or both of them on a different car?

[1781cc]

May be wrong but that might just mean you've got two knackered MAFs there. Have you tried either or both of them on a different car?

I dont have another car or know someone to test it out on, but they were new in boxes?