Late 16v's are supposed to be reliable!

[RobGTI]

I?ve got an intermittent running problem with the car. Its been driving me up the wall lately, I feel like Basil Faulty (i.e. beating the thing with a branch). Anyway what happens is that I get a misfire / kangaroo petrol effect only between 2500 ? 3500 rpm accompanied by a very slight rough idle (it never stalls and always starts and is fine below and above that stated rev range). The problem can last anything between 30 seconds and 30 minutes then goes back to normal. This happens probably about five times a week.

Otherwise the car runs fine most of the time with the exception of a pop from the exhaust under heavy (red line) acceleration.

So far I have checked and or changed the following:
Timing
Dizzy cap and rotor arm
Plugs and leads
Fuel & air filters
Vacuum hoses
Cleaned throttle body
Tried ?bucket? loads of injector cleaner
No fault codes on the ECU when read

Coming to my wits end here?.. Anyone got any suggestions??

[Len]

ECU or Fuel Pump relays mate.

See all the other threads of this nature, there's loads of us that have had the same probs.

Either check em as desribed elsewhere or just go change em both. Cost ya about ?30.

Do that asap if it dont cure it i'll eat a flat cap.

[Overseer]

mine went through a phase of doing this shortly before i switched to optimax full time. also changed the coil (coz it died) and the starter (coz that died next day) around the same time though.

[surreylad1980]

ecu relay for sure, mine done this too p reg gti 16v,

[surreylad1980]

part number 165906381 relay location 3

[Len]

Was trying to find my original posted query, but its too far back, or i keep missing it.

The symptoms described are exactly how mine went, but mine went on longer and got worse.

Mine is also a P reg so it seems very common when the car gets to that age.

Look in the Garage section and a couple of threads are about miss fire.
To check relays - warm up the engine (short drive) switch off and remove relays, if warm to touch (cheek) then o.k. if cold then change, even if cold one side.

[Len]

http://www.golfgtiforum.co.uk/index.php?topic=9093.0


If the above link works it will take ya back to my original thread when i first joined.

I found it! 

[RobGTI]

Yep Len your link still works. The things mentioned all look promising. I'll go and check the relays now if I can find them. By the way the other thing is I forgot to mention sometimes I can hear a relay clicking away under the dash when driving. I don't if that means that the ecu relay is faulty some of the time? I'll post a reply  in 3 weeks to let you know what happened (when I get back off my hols, going tommorow, yipee!) as won't have time to get parts until then.

Thanks for all the responces guys!!

[RobGTI]

Just checked the no. 3 relay and it was warm (all sides). But as it's an intermittent fault surely it works some of the time and gets warm??

[Len]

Well it could be the Fuel pump relay then. Think thats the one next to it, cant remember without checking the manual.