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snapontech
snapontech, Auto Mechanic
Category: Ford
Satisfied Customers: 3803
Experience:  2 Year Automotive Degree 2 years hands on technical training and 7 Years hands on learned from the best.
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Ford Windstar 2000 windstar 3.8 a.c. vents switch to defrost

Resolved Question:

2000 windstar 3.8 a.c. vents switch to defrost on acceleration . new intake gaskets .check valve is working engine vacum is about 15 in. small engine skip at idle .no codes runs good on road 21mpg.
Submitted: 5 years ago.
Category: Ford
Expert:  snapontech replied 5 years ago.

snapontech :

Welcome to Justanswer

snapontech :











Inspect the vacuum lines under the hood feeding through the firewall to provide a signal to the Heating-Ventilation Air Conditioning (HVAC) control assembly and the vacuum tank located in the inner fender apron. If the vacuum lines look to be ok, pull the Heating-Ventilation Air Conditioning (HVAC) control assembly forward and check the vacuum supply on the black vacuum line. This circuit should indicate full manifold vacuum when the engine is running and the line should hold vacuum when the engine is shut off.If the black vacuum line holds vacuum, connect hand-held vacuum pump to the red and green vacuum lines which control the panel door and verify that a vacuum signal can be pulled on the actuator vacuum lines so that the panel door will move properly. Service the vacuum lines, vacuum motor, or panel door assembly as needed.If the vehicle is equipped with a switch for rear auxiliary A/C, disconnect and plug the black vacuum line connecting to the rear switch assembly and recheck for function of the front panel airflow.
Connect a vacuum pump to the white vacuum line feeding the rear controls and check for a possible excessive leak down issue of the line running to the rear. Service as needed.If the front panel airflow works properly with the vacuum line to the rear control switch of the main controls plugged and the line running to the rear is ok, replace the auxiliary control switch at the main control panel. This may be part of the entire front assembly.



Heating Ventilation Air Conditioning (HVAC) Controller

Customer:

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.

snapontech :

So it was not there until you replaced the intake gasket?

Customer:

Correct. Replaced those gaskets twice in the last 5 yrs. due to lean codes, but never replace front valve cover.

snapontech :

I suspect there could be a leak I would use brake fluid and see if there is a change in engine idle

snapontech :

brake cleaner no fluid

snapontech :

sorry bit early here

Customer:

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.

snapontech :

With the EGR unhooked it can cause it to do that

snapontech :

My concern is thats right after you replaced the gaskets it started to do this

Customer:

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.

snapontech :

Thats not right. Its like there is a blockage or something somewhere

snapontech :

But the vehicle runs good but does have a skip did this also happen after you replaced the gasket

Customer:

my brain.

Customer:

yesboth appeared after the last gasket relace.

Customer:

if you bring up idle slightly it smooths out

snapontech :

Let me look into this a bit more

Customer:

fuel trims were good last time i checked .don,t have access to scanner anymore.

snapontech :

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

Customer:

bought this car for wife 6 years ago it,s been great. virtualy no problems except lean codes and intake runner fasteners.

snapontech :

Is it possible one of the gaskets could be wrong?

Customer:

direct from ford . never replaced upper gasket.

Customer:

no check engine light since lasdt repair 6 months ago . not opposed to doing it again. can do it in my sleep.

snapontech :

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

Customer:

don,t know don,t have the access to all data, etc. probably can get it online.

snapontech :

Yeah it looks like they reprogram the PCM and throw in a kit

snapontech :

For that valve cover

snapontech :

I really think we may have a problem with the EGR valve on this vehicle is pretty popular with it being clogged up

Customer:

i,ll try blocking vaccuum to i nterior see what happens .don,t know why i didn,t think of it before.

snapontech :

Yes I was not thinking of it either even though its pointing there

Customer:

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.

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