compression problem

bsc00ter · 06-30-09, 05:02 AM

So I have a 1985 fj60 with a compression problem. when i got the thing it would start sometimes and sometimes it was hard to get going. since then i have rebuilt the carb, put in new plugs, wires, distributor cap, rotor, and coil. also have changed oil, transmission fluid, and radiator fluid. I was told that it basically sat for two or three years. so now i have good spark and gas but the compression is way off. the first cylinder is at 145 and the other five are at 0-15. leak down changed nothing. it has also gone to not starting at all anymore. any suggestions?

roscoFJ73 · 06-30-09, 05:19 AM

It might get some compression with a teaspoon of oil down each spark plug hole.
Or you could try adjusting the valves.
If it starts after a valve adjustment ,you would have to check it again when hot.

But seriously,this sounds like a rebuild.

Engines that ran bad and then were layed up for some time do this. I think any oil or sludge that helped with compression dries up

bsc00ter · 06-30-09, 06:07 PM

so the oil in the spark plug hole didnt change anything.

lehiguy · 06-30-09, 06:14 PM

Quote:

Originally Posted by bsc00ter

so the oil in the spark plug hole didnt change anything.

Have you checked the valve lash? I think it would need to be grossly out of whack to result in what you are describing, but you never know.

bsc00ter · 07-02-09, 05:37 AM

Thanks for the suggestions so far. I'll try some of that this weekend and let yall know.

Gurr · 07-02-09, 01:53 PM

Could put some of that ceramic additive stuff in the motor, called Xado.

This thread talks about it in the end...

http://forum.ih8mud.com/60-series-wa...results-5.html

Heres the website: http://www.autobahnpower.com/product...DO%20Treatment

If you want to go that route

bsc00ter · 07-02-09, 07:40 PM

what does the ceramic stuff do?

bsc00ter · 07-02-09, 07:46 PM

never mind i just looked at the thread

gdtrfb · 07-04-09, 10:21 AM

What happens if you dump fuel down the carb? does it start? my 85 has a simular issue

toomanymachines · 07-04-09, 07:58 PM

If the compression does not come up when you drop oil into the cylinders, then it may either be the head gasket or more likely the valves. Squirt alot of oil into the cylinders that will seal off the rings. if the compression is still low then it has to be one or both of the other things.

bsc00ter · 07-14-09, 06:55 PM

so i was checking the clearance on the valves today and all of them were wrong. so that got fixed except that on two of them the pushrod (i think, it was on the opposite side of the rocker arm from the springs) is up higher than the rest. on those two valves i couldn't loosen it enough to get a gap between the springs and the rocker arm. what does that mean? or mean that i need to fix?

bsc00ter · 07-14-09, 06:56 PM

and putting fuel in the carb doesn't help start it.

lehiguy · 07-15-09, 11:09 AM

Quote:

Originally Posted by bsc00ter

so i was checking the clearance on the valves today and all of them were wrong. so that got fixed except that on two of them the pushrod (i think, it was on the opposite side of the rocker arm from the springs) is up higher than the rest. on those two valves i couldn't loosen it enough to get a gap between the springs and the rocker arm. what does that mean? or mean that i need to fix?

I means that valve is in some stage of it's open cycle. You need to rotate the engine untill those lifters go down. You cannot set lash unless valve is completely closed. The surest way to do that is set one when the companion valve is open and vice-versa.

bsc00ter · 07-15-09, 06:33 PM

when you say companion valve, you mean the exhaust to the intake or is there some kind of relationship between cylinders?

bsc00ter · 07-15-09, 09:20 PM

never mind i figured that out with a little searching.