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Compression needed for the engine to run?

(2003 Dodge Dakota)
in Glasgow, MT on January 27, 2013
Working on a 1995 mitsibushi diamante 3.0.
Like a rookie I went for the fuel pump with a no start. I have 60psi at the pump. Injectors are firing and I believe the relays are working properly. Some carbon by rear tail pipe. Compresion tested the front three cylinders. I have 70 psi 50 psi and 100psi. The car attemps to fire when cranked but will not start. I need to do a wet test on the cylinders. I am thinking the compression is the issue.
The car was also low on oil, none showing on the dip stick. I put two quarts in and it is ok now. The intake nees to be pulled to check the rear cylinders. If they are as low as the front then I have some major engine wear I recon.
Have you ever gotten an engine to run with compression this low?
Displaying 2 answers & 0 comments
Popular Answer
No, the compression is to low to run, you are right compression is the issue. But finding the problem is the answer on how to fix it. Do your wet test if the compression comes up a lot the rings are worn or broken. If not you have a problem in the valves or head gaskets. After looking at the pressures you posted again it is very possible that you have leaking head gasket(s) 70, 50, 100 shows the leak to be between the two low cylinders and moving towards the high one.
on January 27, 2013
no, you need at least 140psi compression all around
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