Running Issues

[bigmoose]

Hi all.  Just got a GTi 8v and was after a little info and assistance.

When the car is warm, the car idles as it should, however the oil light comes on briefly when you back of the throttle and the idle settles.  Also when I turn things on like lights, heater etc the revs drop and then the idle is all over the place and hunts between 800 rpm and 1500 rpm and the oil light flashes at the lowest point of the erratic idle.  I have done an alternator test and all is good.

Now I have been told and oil change and a VW filter might help the oil light, and is there a gasket for the oil filter housing as there  is a lot of oil around where it joins the block.

Any advice greatly received

Cheers

Alex

[Conker]

Is it an 8v K-Jet or digi?

My 16v had exactley the same symptoms as yours and a VW oil filter, oil change and re-set of the idle setting etc. etc. sorted it out. Don't sweat about the idle issue - its prob one of the most infuriating/common problems with the Mk2 but with a little patience you'll have it sorted no problem.

[bigmoose]

It is a Digi, and the idle is doing my head in as I don't have the equipment to set it up properly.

[rubberdubber]

sorry to steal the thread slightly but what is meant by k-jet and digi?

[Khare]

sorry to steal the thread slightly but what is meant by k-jet and digi?

k-jet is a mechanical injection system used in 8v before (87?) and all mk2 16v. After (87?) the 8v got a new injection system called digifant, which is a electronic injection. i think im right in saying they are more economical, and give better performance.

[rubberdubber]

ok thanks  mine is H reg. 1990 so must be digi then! cheers

[rubjonny]

idle switch can cuase this, just check it clicks with throttle shut and the wires to the throttle body havent snapped.  No special equipment required to check the base idle either, follow the rev over 3k 3 times procedure and fiddle with idle screw till its about 900rpm, job done

make sure you have no vac leaks, look over all your vac lines not forgettign the blanked off one to the rear of the throttle body.

[bigmoose]

Right then, oil changed and the oil pressure light stays off.  Excellent.  I now need to have another play at the base idle, but the car still hunts when some of the electrics like the heating fan and lights.  The idle switch clicks once when you turn the ignition on.  I assume that is what you are talking about.

This is driving me mad.  Please help. 

I don't suppose that there is someone in east sussex/west kent to assist.

Cheers

Alex

[Conker]

Assuming the digi is similar to the 16v...  In terms of the idle switch, jonny means that when you open the throttle body lever and close it again you can hear a plasticy "click" noise coming from the tiny switch that sits on the throttle stop that is pressed when the throttle closes. This tells the idle sytem to, errr,  start to idle.

If your motor idles fine with no electrics on, and then hunts when theres an electrical load, it prob just needs a re-tune as the current setting is to close to "the edge" if you know what I mean. For example, I think I read somewhere that you can re-tune the engine with the head lights on to avoid this problem.

Heres the [excellent] guide:  http://www.golfgtiforum.co.uk/index.php?topic=33253.0


PS... If your engine is hunting badly you can get a flashing oil pressure light due to the revs dropping too low (like a stall).

[bigmoose]

After much driving and adjusting, I have seemed to have found a happy medium and I have managed to get the car idling pretty smoothly with electrics on or not.  Now I have a hole in my exhaust.  Oh well I will have to get something different.

Cheers for your help guys.  All I need to do is find someone locally to set the car up properly.