The Ford Barn - View Single Post - Compression test and Vacuum test readings need help

old31 · 12-08-2019, 03:02 PM

Can you help decipher what the numbers are saying, and what would you do?

I have a 6.1 head, bcarb, intake bored.

I forgot to put oil in the cylinders after each cylinder test, throttle is wide open, engine is warmed up.

Compression test. 1:100 2: 90 3: 70 4: 70

Vacuum test: Idle 20. At idle the needle bounces quickly between 20 and 22.
High RPM 18

Needle is always steady throughout the test, except at idle

When I let increase throttle quickly it drops to 0 then goes to 25, then back to 20.

12-08-2019, 03:02 PM	#1
old31 Senior Member Join Date: Jan 2016 Posts: 2,103	Compression test and Vacuum test readings need help Can you help decipher what the numbers are saying, and what would you do? I have a 6.1 head, bcarb, intake bored. I forgot to put oil in the cylinders after each cylinder test, throttle is wide open, engine is warmed up. Compression test. 1:100 2: 90 3: 70 4: 70 Vacuum test: Idle 20. At idle the needle bounces quickly between 20 and 22. High RPM 18 Needle is always steady throughout the test, except at idle When I let increase throttle quickly it drops to 0 then goes to 25, then back to 20. Last edited by old31; 12-08-2019 at 05:12 PM.