83' mk1 gti running problem, HELP

[2l_16v]

Hi, my brother just bought a standard mk1 gti, appeared to be running fine then developed a problem when it got hot. Then after this we couldnt get it to idle below about 3k rpm, found out there was no current going to the Auxillary air valve, further investigation and there was no fuse. put a fuse in and replaced the valve as it was buggered. seemed to solve the problem. reset the idle let it run for a while and everything seemed ok.
Took the car for a run and as soon as you go to give it sum, the car stutters vilently, so its fine when its not under load, but as soon as you drive it, its awful. only seems to be a problem once its up to running temperature, its fine when its cold.

The other thing, the coolant temp guage, the red light is flashing all the time, and the needle is always in the red, but the car doesnt over heat, the oil stays cool and the fan cuts in and out as it should.

I hope somebody has some idea what the problem could be, as its driving me and my brother around the bloody bend!!

thanks....

[Downsey]

This happened to me - it was a filthy fuel filter for me - replaced - fine & dandy now!!

[Mk1Mad J - 16v]

Sounds like fuel to me too 

As for the temp guage - that sounds like its grounding out somewhere or the sender is fooked

[2l_16v]

the fuel filter attached to the meetering head assembly? is there also one underneath the car like my mk2 16v?

And why would it only do it when its hot?

[Mk1Mad J - 16v]

Yeah the one on the head, you can take it off a blow into it going against the directon arrow and get the crap out rather than wasting £15 on a new one  (be sure to fit new washers or you could be p!ssing petrol into your engine bay)

How loose is the idle screw, if its adjusting itself the o-ring's probably knackered - you can get a new idle screw for about £10,  unless you can find an o-ring the right size somewhere.

How old are your plugs & leads? old plugs get the hump when they're either really hot or cold & old leads are just sh!te 

[x5pea]

I had a similar problem with a previous car, turned out to be the cold start valve....

If the problem (stutters) only exists when you floor it,i would say that the engine is getting flooded. When you are pushing the accelerator you are forcing more petrol thro the engine to make car burn it quicker and make the car go faster...


Sounds to me that the engine cant handle the fast flow of the petrol, with petrol issues it can be hard to identify a specific fault. Generally i would replace the cheepest things first, someone mentioned a similar problem resolved by replaing a fuel filter. If you have done the cold start valve check its been set up correctly.......

Try tightening up the idle screw half a turn and see how it runs, always do this when the car is warmed up... If it still ticksover OK take it for a spin see if the issue is resolved, if not try another half turn and so on... Should idle between 750 - 1000 rpm depending on your ignition system