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Discussion Starter · #1 ·
I have a '91 tbi 350 with 70k original miles. When I tested compression I got between 130-135 in each cylinder. I did this by jumping the engine sitting on a stand with jumper cables and a little battery. I supposed it could be higher once it has a good electrical source. Is this good compression?
 

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QuickerPICKerUPer
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It should be enough for it to run but it seems like its a little on the low side. Most new motors run around 180 psi of cranking compression.
 

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tastes like burning
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try pouring some oil in the cylinders and try it again. if it brings up the compression, it needs help. just to be sure, you had all the plugs out and the throttle wide open right??
 

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Discussion Starter · #4 ·
IHEARTCARS said:
try pouring some oil in the cylinders and try it again. if it brings up the compression, it needs help. just to be sure, you had all the plugs out and the throttle wide open right??
I tried the oil, it didnt bring the compression up. I did have the throttle wide open, but I only pulled the plugs one at a time. Im going to try it again tomorrow with all the plugs out and a good battery
 

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tastes like burning
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yeah, you won't get the correct reading if you only pull one at a time. also, if the starter is not up to par, you will get incorrect readings.
 
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