Welcome to Justanswer
will try this . no separate switch to rear ac problem seems to occur mostly at highway speeds . is 15 in of vacuum enough have man vacuum on black to switch and diaphram .just doesn,t seem enough ?? Problem started immediately after intake gasket & bolt replacement.
So it was not there until you replaced the intake gasket?
Correct. Replaced those gaskets twice in the last 5 yrs. due to lean codes, but never replace front valve cover.
I suspect there could be a leak I would use brake fluid and see if there is a change in engine idle
brake cleaner no fluid
sorry bit early here
Tried it yesterday. No change in idle. Is it normal at idle that the line to the EGR valve when it's unplugged, flutters in & out like it's pulsing.
With the EGR unhooked it can cause it to do that
My concern is thats right after you replaced the gaskets it started to do this
I'm a ASE master tech myself, retired. My concern is the same. It should have more than 15 inches of vacuum, engine condition excellent. I have vacuum checked most everywhere you've mentioned and find no leaks. All hoses are in excellent shape. There was somthing in the TSB for the lean codes about changing the front valve cover. Back when I looked at it it seemed to me that it passed the criterea for not placing it. I know, lots of questions, but this has been bugging me now for over a year. I've had this apart 3 times in the last 3 months just double checking for vacuum leaks & just can't seem to solve it.
Thats not right. Its like there is a blockage or something somewhere
But the vehicle runs good but does have a skip did this also happen after you replaced the gasket
yesboth appeared after the last gasket relace.
if you bring up idle slightly it smooths out
Let me look into this a bit more
fuel trims were good last time i checked .don,t have access to scanner anymore.
This is the same engine they throw in the Lincolns not a fan they seem to be a problem I have owned two and they always were trouble
bought this car for wife 6 years ago it,s been great. virtualy no problems except lean codes and intake runner fasteners.
Is it possible one of the gaskets could be wrong?
direct from ford . never replaced upper gasket.
no check engine light since lasdt repair 6 months ago . not opposed to doing it again. can do it in my sleep.
I would check the AC control assembly for the skip I suspect something strange is going on. Are you referring to TSB 03-16-1
don,t know don,t have the access to all data, etc. probably can get it online.
Yeah it looks like they reprogram the PCM and throw in a kit
For that valve cover
I really think we may have a problem with the EGR valve on this vehicle is pretty popular with it being clogged up
i,ll try blocking vaccuum to i nterior see what happens .don,t know why i didn,t think of it before.
Yes I was not thinking of it either even though its pointing there
egr positioners were almost as bad as dpfe sensors . next thing i,ll try is cleang egr .buy a valve cover, and get it reprogramed . thanks.