Very Weird Compression Problem

[4g67rst]

I have a 90 Laser FWD with a turbo 4g67. I couldnt get it to start by cranking it, but it will run all day if I bump start it. I am getting fuel and spark but my compression is horrible. I ran a compression test and this is what I got back. 0-25-40-110. What is going on with my car? I know these results are horrible and way too low for a car to run off of. I really need help with this. By the way, the car actually drives but is really under power but that was before I reset the timing (it was off 1 tooth). I havent drove since the compression test.

 

[eclipsegsx1736]

Try doing a wet compression test, and see if the results change. Post the results here.

Add one capful (1-2 tablespoons) of oil to the cylinder with low compression.

Let it sit for a minute to allow the oil to flow down and coat the sides of the cylinder and piston. If there are any gaps in the rings, the oil will seal them for the next few minutes.

If the reading improved significantly (more than 30 psi), your rings are probably worn.

If there is little or no improvement, take it to a garage that can perform a leak-down test to determine where the compression is escaping (intake, exhaust, crankcase, gasket, etc.).

 

[Old Mitsu Tech]

If you had horrible smoking then likely it's rings. If it didn't smoke, probably valves.

If you have no history with this car well, the oil in the cylinders will give you a good idea.
Timing belt being off a tooth shouldn't have bent valves. 3 or more will. Either way, the head needs to come off. Have the head machine shop tested and have them provide you with an estimate of repairs. However, as old as the engine is and as many miles as it likely has, if you can re-ring at the same time, it's a good idea. Rarely does it happen, I've seen about 2 or 3 in my life, but when you re-do a head once in a while the bottom end can't handle the renewed top end. The up side? None of them were Mitsubishi.

If the ridge in your cylinders is almost non-existent I probably would leave it as it is.

That's a decision only you can make given you can see it.

Good Luck

 

[4g67rst]

I'm 100% sure its not the rings. I had to put in a piston because a rocker broke and sent a valve through the #2 piston. But the bottom end is brand new and I have a ported and polished head with around 70,000 miles on it. the block doesn't even have 50 miles on it yet. I'll try the wet test but I still can't see why it runs with the compression that low. I was thinking about using some seafoam if nothing else works because I did have a whole lot of carbon buildup in the throttle body and intake manifold. i really appreciate the advice though, keep it coming if there's any more ideas. thanks

 

[ChicksDigBoost]

I would do a leak down test, it will tell you whats going on. Your valves may not be seating properly after your port/polish and valve job.

 

[titogs95]

I would do a leak down test, it will tell you whats going on. Your valves may not be seating properly after your port/polish and valve job.

Agree. Leakdown should be perform to confirm the condition of the valves....
Good Luck