OK, I got an OBD1 DOHC ZC from a guy who was going to put it into his EF but he didn't want to put the effort into reverting it to OBD0. The motor looks pretty good overall and it still had the cut harness, hoses, and a flexplate on it which means it came out of an automatic something over in Japan. Anyway, I did an extensive series of compression tests on it before I started thinking about putting it in my car. The compression tests always came up 195, 270, 240, 195. I tested dry, wet and both ways at closed throttle and WOT and the numbers all came up the same. What does this really mean because I have never encountered this before. Is it good or bad?

 

what gauge are you using?

my cheap *** $20 bux gauge pales in comparison to my mechanics $400 bux snap on comp tester.

also crank the engine around 5 times PER CYLINDER, also have someone watch the gauge as you crank it.

 

Its a generic gauge but thats not the problem because I have used it a few times before and it has always been accurate. The engine has plenty of oil in it and I made a test setup by using a spare transmission, starter, and battery so I ran a pretty comprehensive compression test. I did turn each cylinder over at least five times and I watched it every time and they all built compression at the same rate, only the number 2 and 3 cylinders went higher than expected.

 

do a cylinder leak down test and youll know where your problem is

 

Yeah, thats what my next logical step should be. Any ideas who has a leak down tester thats not too expensive?


Modified by MREG2 at 7:58 PM 4/26/2008

 

you could make one you just need somethin to be able to send a 100psi into the cylinder then just listen for the leaks. use the comperssion tester line and take the valve out of it so it can flow air in both ways conect a compressor tip on it and send a 100psi into the cylinder

 

I have a compressor but my compression tester has a funky quick disconnect on it so I'm going to have to make something else work.