engine help

ras50gt

Member
Oct 25, 2005
200
2
19
not a mustang but thought someone here could help me out....

A friend of mine has an 86 gmc jimmy, has 350 in it-carbed, all stock, about 120k miles on it. He has had the truck for a month or two. The car use to smoke a little when you first start it. He noticed a little oil on the ground the other day but I don't think anything serious. Then he noticed some coolant leaking, his uncle who works on cars took out the radiator which appeared newer and cleaned it up, welded some spots and that seemed to solved that problem. Anyways, my friend was told by the person that he bought it from that it would need a new choke. My friend never got one as the car seemed to drive perfectly. The last week or so the car has been hard to get started so not sure if that could be the reason. Two days ago his uncle did a compression test, my friend called me up today and said that he didn't have any compression in the 7th. His truck will start(with a little trouble) but if the idle goes down it will die, I guess it happened to him today while driving to work when stopping at a light. He asked me for advice but im not sure what to tell him, any help on this one?
 
perform a wet cylinder test to determine if problem is in head or rings....

If any cylinders are low then a "wet" test can be done. This involves squirting a few ccs of oil into the cylinder and repeating the test. The oil will help seal bad rings and increase the reading but won't affect it if the problem lies in the valves or head gasket...copied from link below click on link below and read...

http://www.pumaracing.co.uk/comp.htm
 
As far as I know, one cylinder is done for. But he can still drive the car? Could that be the problem with it dying when at low idle? I first thought something to do with the valves or a head gasket...