what is the normal amount of vacum our cars should be pulling ? assuming it is a good running motor with no vac. leaks. im getting about 19 inch. in park and about 16-17 inch. when in drive. this is at normal operating temp. 185-190. im suspecting my lower ic tube is the culprit. as i have gone through all the vac. lines behind the blower and plenum and they all look good. the reason why i think i have a vac. leak is because when i start it when it is cold it revs to about 1800-2000 rpm
vacum ?
- Thread starter tmz93sc
- Start date
I think those are good numbers....better than mine
Have you replaced the IAC lately? Gotten creative with adjusting idle/throttle plate opening?
i figured those were good numbers. iac was replaced last year with a motorcraft unit, it could be sticking? i just dont recall having the motor start up to 2000 rpm when i start it
also i forgot to mention the shop who did my hg,s forgot to put the teflon gasket on the lower ic tube where it meets the return plenumarcherman0531
Registered User
My 90 xr7 did the same thing. I smoked the engine 3 times and it showed no vaccum leaks. I replaced the IAC, problem solved! The plastic accordion inside the IAC was cracked and broken.