Golf GTI lumpy idle - Andrew Barnes

My 1989 Golf GTI 8V (digifant injection) has always had a slightly lumpy idle, but recently things have got worse. The lumpiness is felt throughout the car. I have changed the plugs, leads, cap, rotor arm, cleaned out the valve on top of the engine, cleaned the idle screw all to no avail. Does anybody have any ideas, does the whole intake system need a clean? Its all quite black inside.

Thanks

Andrew
Re: Golf GTI lumpy idle - Matt Kelly
That's you, me, Lacey G & Ben Chapman who own or have owned MKII GTIs. Unfortunately I don't know what causing your problems but you seem to have tried most of the likely causes.
Re: Golf GTI lumpy idle - David W
Andrew,

Don't have too much to do with these cars but historically have experienced valves burning out on this engine type to give the fault you describe.

This has been with older Golfs, Jettas and Audi 80s.

Hope some of the GTi boys will find you an easier answer.

David
Re: Golf GTI lumpy idle - David W
Oh yes and one 1.8 VW with a worn out cam (due to head oil feed failure) that did the same.

David
Re: Golf GTI lumpy idle - peter
I suggest a visit to clubgti.com. A very good site with a technical forum with answers from people who generally are experienced with older VWs.

However my 87 GTI mk2 8v K tronic has a very pronounced dead spot at 1600rpm particularly notiecable when hot. Otherwise very good smooth power, pulling evenly from 1000rpm in 5th! (The dead spot is also there in other gears). Any ideas? I most post this at clubgti. as well.
Re: Golf GTI lumpy idle - Adam Going (Tune-Up Ltd)
Andrew,

Suggest you check for air leaks around the petrol injectors where they enter the head - rubber seals here go hard over time and frequently leak, upsetting mixture to individual cylinders. Check by spraying carb cleaner in area of injectors - if engine note/speed changes you have a leak. Could also be an inlet gasket leak, and perhaps worth doing both if this test is positive.

If mixture is excessively rich ECU problems are not uncommon, but due to cost you should have the whole system checked out first.

Regards, Adam
Re: Golf GTI lumpy idle - Andrew Barnes
Adam

Tried this tonight and there was a change in engine note when I sprayed the injectors. I have decided to strip it all down, replace the inlet gaskets/injector seals and clean the whole lot up. Hopefully this should alleviate the problem.

Thanks Chaps
Andrew
Re: Golf GTI lumpy idle - David L
check the two temperature senders on the casting where the top radiator hose goes into the engine one of them is a temperature sender purely for the ecu if this one starts to go haywire it messes uo the mixture giving lumpy idle and also effects the ignition timing also giving poor running also check the timing has been set properly with this sender disconnected
Re: Golf GTI lumpy idle - David m
sorry the last message isnt from dave lacey its from me so dont shout at him if im wrong hes just been using my computer and changed the name on here sorry
 

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