1uz Compression Test help

[Anthonygrud]

okay , so i have my 1uz on my engine stand its a 1992 ls400 1uz , i need to compression test it to see if i should continue this motor or go and get another .. im thinking i could just wire up the starter and get it to crank over just enough for a compression test , could this be done? what should the compression be for each cylinder?

thanks , anthony

 

[cribbj]

Did your engine arrive with a flexplate already mounted to the crankshaft? If not, you'll need one of those before you can spin it. Depending on the year and compression ratio of the engine, you could see from 150 to over 200 psi per hole. What you're interested in, however, is consistency. The compression results shouldn't vary by more than say 5-10 psi.

 

[Anthonygrud]

yes the flexplate is on the motor ... ive taking the headers and spark plugs out and it looks like a good old motor to me ... burns evenly , not alot of carbon build up , spark plugs are in good conidition , so im hoping for a good compression from each cylinder ... the starter wire is the giant black one correct?

Thanks , Anthony

 

[gloverman]

If the motor has been sitting for a while its not unusual to find the compressions all over the place due to carbon drying out and surface rust on some parts. It often helps to give it a good crank over before testing. If you can fire it up first its even better. Cheers

 

[Anthonygrud]

thanks everyone for all the replies ..

I dont have the ECU so firing it up is out of the question , i believe the best thing i could do is use the starter to crank it over. Anyone have any information on that?