Compression test info please

[Papabear]

1994 7.3 IDI
2 questions
1) what numbers do i want to see for comp numbers ie. pass/fail
2)should i just disconnect a fuel line so the engine does not catch during testing or just pull all glow plugs so only th ecylinder i am testing gets compression.

i have the haynes diesel techbook and it does not say and online i found a site that say 195psi is good and a local mechanic says anything under 400psi is a fail please advise

 

[FordGuy100]

I think its put power to the FSS (fuel shut of selenoid) to keep fuel from being pumped from the IP to the injectors. Might be take power away...I dont know its late I'm going to bed.

 

[FordGuy100]

195psi isnt enough. Calvin (towcat) has the exact number, but I think the minimum is 350psi,

 

[Papabear]

how do i contact towcat to find out for sure

 

[towcat]

1994 7.3 IDI
2 questions
1) what numbers do i want to see for comp numbers ie. pass/fail
2)should i just disconnect a fuel line so the engine does not catch during testing or just pull all glow plugs so only th ecylinder i am testing gets compression.

i have the haynes diesel techbook and it does not say and online i found a site that say 195psi is good and a local mechanic says anything under 400psi is a fail please advise

here's what I do on compression tests....
1) pull all glow plugs. it's alot easier on the starter pushing on only one cylinder.
2) 300psi is the minimum for a diesel to fire.
3) all pressure readings need to be within 10% of avg or you will have a motor that will idle like a "cammer"
4) one last thing....if you pull the injection pump and the lines, that is the most ideal time to do a compression test.
good luck!

 

[Papabear]

thanks i will report back with the numbers