Idle and running problems

[koukoudaman]

Greetings from Athens!

I have a Golf mk3 with the ABU 1.6L engine facing some problems!
I've already uploaded a video in youtube.

Running and idle problems are my daily issues for long time now!
Car stalls and dies at idle at all engine temperatures (cold /hot), hesitates at all rpms and runs bad.

If you watch the video, you can understand better what i'm talking about!


http://www.youtube.com/watch?v=eHO5VJpPloI&feature=plcp&context=C3b39ab5UDOEgsToPDskLHXJvObhGMB3P58Yigt5sF

Things i've checked and changed:

-Spark plugs
-Distributor cap and rotor
-Spark plug wires
-Coil pack
-Coolant temperature sensor
-Lambda sensor
-Changed the whole injection unit wich includes new TPS sensor, injector, fuel pressure regulator, idle control switch, intake air temperature
-Vacuum lines

This problem drives me crazy day to day..

Please people, help me..

[Khare]

Welcome.

Have you tried cleaning/replacing any earths? Mine had an idle problem, VAGCOM pointed towards CTS so I changed it, still no joy. In the end it turned out to be a loose earth (gearbox one). Check all the earths and use sandpaper or a wire brush to clean them and where they connect to.

I don't know much about anything about the SPI engines, but does it have an ECU and fuel pump relay? If so it could be one or the other, or both that may need replacing.

The other thing I'd try (I'd do this first too) is to clean the throttle body with some carburetor/air intake cleaner.

[koukoudaman]

Welcome.

Have you tried cleaning/replacing any earths? Mine had an idle problem, VAGCOM pointed towards CTS so I changed it, still no joy. In the end it turned out to be a loose earth (gearbox one). Check all the earths and use sandpaper or a wire brush to clean them and where they connect to.

I don't know much about anything about the SPI engines, but does it have an ECU and fuel pump relay? If so it could be one or the other, or both that may need replacing.

The other thing I'd try (I'd do this first too) is to clean the throttle body with some carburetor/air intake cleaner.

Thank you Khare.

Yes, i cleaned all the earths (at least i believe so), cleaned the throttle body and made an alignment using the VAG Com.
I also checked the wiring. VAG Com keeps giving the following error all the time:

00670 - Throttle Position Sensor (G127) 03-10 - No Signal - Intermittent

I made a check to the wires coming from the TPS sensor to the ECU according to the AutoData and all seems to make good contact. None of the cables are spliced or something like that.

I have also changed the fuel pump relay. I don't think that my car has an ECU relay.

[Khare]

http://wiki.ross-tech.com/wiki/index.php/00670

Have a look there, although you've done what is listed as a solution. It may be the TPS (back box mounted onto the throttle body) has a fault itself. I think the only thing you've got left to try before you start to really dig deep is try changing the throttle body for one that you know is working. Hopefully that should cure the problem. If even with the working throttle body it still stalls and idles bad then I'd try changing to an ECU that again, you know is working. If that fails too then I think it's a question of checking each individual component separately, until you find a fix.

[camhaz]

I have a 1.8 with the SP injection unit and had similar issues, replaced heaps of parts over a 12 month period without fixing anything, and trying 3 different VW specialists without any luck.

Finally someone suggested the fuel pressure could be low, so I bought a cheap fuel pump off ebay and the car now has heaps more power, and economy is getting close to what I would have expected (~500km per tank).

In hindsight it probably would have been better to take it to a mechanic with the equipment to measure the fuel pressure first. The Bentley manual suggests fuel pressure is the first thing you should test before looking for other faults, because if it is not right to start, then you are wasting your time.

Cheers,

Rob.

[koukoudaman]

I have a 1.8 with the SP injection unit and had similar issues, replaced heaps of parts over a 12 month period without fixing anything, and trying 3 different VW specialists without any luck.

Finally someone suggested the fuel pressure could be low, so I bought a cheap fuel pump off ebay and the car now has heaps more power, and economy is getting close to what I would have expected (~500km per tank).

In hindsight it probably would have been better to take it to a mechanic with the equipment to measure the fuel pressure first. The Bentley manual suggests fuel pressure is the first thing you should test before looking for other faults, because if it is not right to start, then you are wasting your time.

Cheers,

Rob.

I have already replaced the fuel pump and relay and no luck. Car does the same thing for 8 years now, including the time with the old fuel pump.
The fuel pressure is about 0.8-1.2 bar, as expected to be!
I have taken the car to about a dozen of mechanics who always try to find the problem by changing parts all the time! I've spend about €300 with no luck. I won't spend any cent again! Besides that, im a mechanical engineer so i understand how things work.

Do you know if there is any adjustment i have to make to the fuel pressure regulator in the injection unit?

[Stirring Moose]

You say you have checked all earths. Don't know if your car will have it but on my 16v there's an earth stud under the battery tray (you have to remove battery and tray to access it). Have you checked this? It's easily missed - I didn't know about until recently when another Forum member put me onto it.

S.M.

[koukoudaman]

You say you have checked all earths. Don't know if your car will have it but on my 16v there's an earth stud under the battery tray (you have to remove battery and tray to access it). Have you checked this? It's easily missed - I didn't know about until recently when another Forum member put me onto it.

S.M.

Hm.. Do you have any picture of it? I will try it for sure! There is an earth behind the battery and under the coolant reservoir which seems to be ok.

I made several scans today, and took these results from the vagcom:

1st try:  1 Fault Found:

00532 - Supply Voltage B+

        07-00 - Signal too Low

2nd try:  1 Fault Found:

00516 - Closed Throttle (Idle) Position Switch (F60)

        29-00 - Short to Ground

3rd try:  1 Fault Found:

00525 - Oxygen (Lambda) Sensor (G39)

        29-10 - Short to Ground - Intermittent

Something is going wrong in my earths or/and my electricity in general!
When im looking at the ECU wiring diagram, there isn't a common earth between them!