Golf vr6 k reg !!missfire no power!!!!

[Vrcus 0]

I have a 1992 vr6 no power when driving and missfire on idle now and then.when stationary if you full throttle it would cut out if you rev slow build it gradually it will rev and sound awesome with no unwanted sounds.it has a old obd1 connection when plugged into a snap on solus ultra diagnostic it says no communication. Fitted new plugs ht leads distributer arm. I was parked outside my friends house just showing him the car next minute the engine must of got too hot and started leaking water out of the overflow on water bottle because it's red hot they was loads of steam I thought engine was ended but it cooled down and drove home and parked up ????????? 

 

Edited August 6, 2017 by Vrcus

[Sam00Cleveland 12]

Sounds like a potential head gasket problem to me, likely between 2 cylinders - have you done a compression test ?

[Vrcus 0]

Compression test full compression new plugs leads refurbished dizzy ignition coil ???

[Wasted73 0]

Throttle position sensor or crank sensor.

[deyres 0]

1st off, im no expert, but my 2p worth

 

see if your radiator is getting hot? If the car overheated then could be that the thermostat is knackered, since the temp sender is around that area that could be misreading and causing the ECU to overfuel and its running rich? So if you can test the emissions see what its running at. You could have an air lock so check the heater in the car, is it getting warm, if not possible air lock. When cold, Open the expansion tank, start the car and let it get up to temp, if you see bubbles in the coolant then you have air in the system. Dont let it get too hot. 

 

If you have access to VagCom then check the throttle position sensor output with the charting function and move the throttle and look for a for a smooth curve, any jumps and its bad. If you have access to VagCom (and assuming it works) then look for Throttle Adaption limit reached indicating a dirty throttle body and if so its time for a clean. Its easy, plenty of DIYs. 

 

MAF sensors could be another cause of woes. You could try a clean with pure alcohol or MAF cleaner. Dont use any old stuff its sensitive.  

 

Also Look up The humble mechanic on you tube, he's in the states but will reply to questions on email via a pod cast.

 

I only have an ODB II so not sure about what you get on the ODB I cars, but hope this helps.

[noggin 29]

I was going to suggest TPS or Lambda Sender. I had a crank position sender go and the car wouldn't even turn over.

[deyres 0]

I had the Crank sender go and it would turn over but not fire. Called AA and he said they can get magnetised so just pull connector and short it out and off I went.

 

Lambda sensor shouldnt give you too much grief, mine has been broken for ages and it still runs reasonably well.  Im told that if the Lambda stops working the ECU ignores it and tries its best to work out filling from its other sensors. May be a bit off, but I dont think it would be that bad.I get pretty good MPG so cant be too bad but then again i drive like an old man as i am one.

 

My first stop would be a Throttle clean, its not a hard job and can even be done with the Throttle on the car. But the overheat is a bit more of an issue. 

[noggin 29]

When my lambda sender went the car was popping and farting but it would make forward progress. I drove from my house to the garage, a trip of a mile and a half. The garage put up the car on the ramp and the catalytic converter was glowing red! We removed the lambda and I ran it without one for years.

Edited October 21, 2017 by noggin