Page 1 of 1

Air Compession Test - Help ! East Sussex

Posted: 11 Aug 2009, 09:23
by woodys
Hi People,

Before i throw anymore money down the drain , is there anyone on here that could lend me a hand and do a compression test on my 1970cc Aircooled 1981 t25

I broke down the other day, got towed home by the AA and the chap seemed to have little knowledge on the breakdown

To break it down, bought the vehicle and seemed to run fine maybe a little sluggish , had a 50 mile journey home no problems

a couple of days later i noticed a missfire

changed the spark plugs and seemed a little better

drove 20 miles to a local vw show with no problems

drove back home, lost power up a hill, dropped from 50 mph to 30 rapidly , then bad missfire , lost power all together

AA tested spark to all plugs and seemed ok apart from one lead that he changed, drove away and engine cut out all together

He said i need a new set of ht leads??? surely the vehicle would run on 3 cylinders but really lumpy ? he said because its a large vehicle the engine wouldnt cope and would cut out , well, im not convinced


Im from Peacehaven in East sussex and im prepared to pay someone to come round, have a look, do a compression test ( i havent got one ) and hopefully get me back on the road before summers out

I would be very very grateful to anyone that can help me - im desperate and cant afford to waste money

Thanks for your help and answers in advance

Re: Air Compession Test - Help ! East Sussex

Posted: 11 Aug 2009, 10:11
by gsmoke
You get good and bad aa men. This one seems to have fallen into the latter category.
Doing a compression test is not much harder than changing the plugs. You can buy a compression tester from most motor factors for under 20 quid. A good guide to doing the test is here.
https://club8090.co.uk/forum/viewtopic.p ... t#p7386202" onclick="window.open(this.href);return false;
Hpoefully, the compression test will prove ok, then I would go back to basics.
Check that the fuel filter is not gunked up under the van and that petrol is getting through the carbs. (the plugs should be a bit wet after cranking the engine over.
If fuel is going in ok, then the problem will be ignition, start at the plugs, then leads, distributor cap, rotor arm, coil and work back until you find the fault.
The problem could well be ignition based, but I would discount the fuel system first.
Good luck.