Engine Vacuum

[koldcustoms]

How much vacuum would a healthy stock '87 2.9L pull? I can't find a spec for it in my manuals. The engine has a 58mm throttle body, so I'd assume it'll pull less then an '88 and up 2.9L.

Thanks

 

[Otto]

My 4.0 gets about 26

 

[koldcustoms]

Great!!!?

 

[holyford86]

I get about 15-16 in hg at idle with the IAC plugged in, unplugged its about 20 or so.

 

[AllanD]

a properly running engine will typically pull 20in/Hg at idle

the throttle body size doesn't matter because idle is related to
manifold absolute pressure...

at Wide Open Throttle manifold vacuum will typically be -0-
unless your air filter is packed with mud.

AD

 

[Dany77]

Where is the best spot on a 4.0L to tap into the vacuum line to test ??

 

[holyford86]

an unused vacuum port.