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Compression numbers. 1uzfe gurus please step in.

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Old 02-06-11, 11:11 AM
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sebasc300
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Unhappy Compression numbers. 1uzfe gurus please step in.

I recently did a compression check on my sc400.

The right side bank read 120 psi all the way across.

The left side bank read 180 psi all the way across.

the car still will not start. I have spark and fuel.

Should my car at least run with these compression numbers?
Old 02-06-11, 04:21 PM
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FatBrian81
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It would run, but not extremely well. Did they test each cylinder individually or each bank as a whole. Ideally you would do it individually to pinpoint a specific cylinder that might have a problem. I would recheck the right bank to try to find the problem.
Old 02-06-11, 04:37 PM
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sebasc300
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I tested each bank as a whole, One by one of course.

The plugs were fouled out pretty badly, so I replaced them with ngks and she started up for about 5 seconds.

I'm getting codes 21,24,28,31, and 78 for the fuel pump bypass.
Old 02-06-11, 05:36 PM
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FatBrian81
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I'm not sure about the codes you're getting, you might have to search for them. Its very odd your whole right bank would be 60 psi lower than the left, something is wrong here.
Old 02-06-11, 05:41 PM
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LiCelsior
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21 - Main oxygen sensor signal (on left bank)
24 - Intake air temp. sensor signal
28 - Main oxygen sensor signal (on right bank)
31 - Air flow meter signal

and there is no 78.
Old 02-06-11, 05:58 PM
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MidloSC
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If you did the compression test on a cold engine it won't be accurate. On the cylinders that tested low, put a tablespoon of oil in them then retest them and see if the compression increases. Ultimately you should do a leak down test.

Last edited by MidloSC; 02-07-11 at 02:57 AM.
Old 02-13-11, 07:01 PM
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willhickey
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listen to midlo sc!!!!
Old 02-13-11, 07:18 PM
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sebasc300
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Thanks for all the help guys.

I have decided to Yank the 1uz in favor of a 2jzgte vvti.

New engine is on the way.
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