I'm working on an 89 F-150 4.9 Litre that sat for two years. I got it started but it was missing and idling really rough, so I ran a compression test with one of those compression testers you hold against the spark plug hole. I got between 140 and 150 on cyl 1 & 3-6. Cyl 2 was around 25. I read somewhere to squirt oil in the clyinder and if the reading comes up it indicates worn rings. I squirted some oil in cylinder and bam 150. As I said the truck has sat for 2 years, so it hasn't run, but when I changed the oil I didn't see any water or that odd butterscotch colour when oil and coolant mix. In addition, I don't seem to be loosing any coolant. Both cylinders on each side are fairly close, so I'm not thinking head gasket. Oh.. the truck doesn't really smoke either.

So some questions:
1) Is the 125 lb increase feasable with just adding oil?
2) If it is feasable, then I'm thinking rings. Would that be a fairly accurate assumption? If that jump isn't feasable, what should I be looking for?
3) I'm not a mechanic, how difficult would replacing the rings be?
4) Is there a "dummys" guide to engine rebuilding? I know all the "technical" steps (remove the head, sorta' thing). What I'm looking for are the practical hints that keep you from screwing up a rebuild.
5) I've been told all the steps you "should" do when rebuilding an engine, is there a reasonably reliable low buck set of steps to follow? This is going to be a camp truck.. to and from camp every other weekend (about 24 miles round trip) with little else asked of it..

Sorry for all the questions, but like I said I'm fairly new at this. I am enjoying messing with the old truck, but everyone else has dubbed her "Christine"...

 

Sounds like you had a stuck ring or more likely a valve that was not closing all the way at first.
Start the engine and warm it up, take the plugs out after it cools down and do the test again.
When you do a compression test you are to brake each plug loose, this dislodges the carbon at the end of the plug. Then run the engine a short time to get rid of the loosen carbon. Then take all the plugs out and with wide open throttle check each one with a compression gauge.

 

Thanks Sub. I just removed all the plugs and did the test cold. I'm borrowing a screw in compression tester from a friend, and I'll re-run the test as you described above.

 

Oh, should I disconnect the fuel pump relay so there isn't any fuel going to the cylinders?

 

Remove the EEC Power relay, that way the fuel pumps will not come on and the injectors will not fire.