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hey guys
i know this is a hot rod site but im lost on this thing,it a v6 2.4 overhead valve
well it starts then idles high ,then idles real low and most of the time it stalls out . it starts right back up . i changed the throttle pos sensor and the idle air control control valve .
got any ideas ????
i really need some help on this one
thanks
jeff mc
Sounds more like a vacuum leak. Have you had the chance to pull the error codes?
Bill S.
bill
the check engine light is on ,i am getting a egr code for that . the car was running fine even with the check engine light on
this problem just came about in the last week or so
ill check the vac system this week end
thanks for the repones
jeff
a good check is to spray a little starting fluid around the intake area while running. if you have a leak you should see a rpm change
In my experience if you ignore the check engine light and run with error codes the PCM/ECU may restrict outputs based on its program. I would run the codes, see which one(s) make sense, and then at least clear the codes so the computer has a chance to control per design. If/when the check engine light comes back on in normal driving, run the codes as soon as you can, before it stacks up a bunch of other codes which may really be caused by the computer logic and not by your root problem. Like Bill says, you may have a vacuum leak, and it may cause the computer to "see" a problem that is not really there, throw a false code, and maybe even control erratically. Clearing the codes may guide you to the problem.
While not symptomatic to the problems that you describe, that car model year are famous for head gasket problems. Trust me... been there...
a clogged egr passage will cause a running condition. as will a stuck egr valve. heck, with any car, put vacume on the egr valve and see what happens as its idling. it will stall, or come darn close to it.
most common on fords is P0401, insufficient egr flow. test the egr by putting 15in/hg to the egr valve and notice for a change in idle. if there is no change, pull the egr, clear the passage in the intake. reinstall the egr valve and retest. if there is a change in idle test the dpfe sensor. you will need a scan tool to do this. at least ive never tried any other way. if the dpfe is out of voltage, replace it. if i remember right, it should be at around .9v at an idle.
ive only seen a hand full of P0402 which is exesive egr flow. most likely in this case its the egr valve sticking opened. pull the egr and inspect it for high carbon build up. if theres a lot, clean it out and bench test it to see if the diaphram is working. reinstall and test with vacume. listen for an idle change. the dpfe could also cause the excesive egr flow so it should be tested.
annother VERY common problem with the 2.5 v6 motors is the butterflys in the secondary intake runners sticking open. normally this causes surging on the freeway and lack of low end power. but id imagine it could cause an idle concern.
as stated above, check the codes and work off of those.
bob
The problem might be a idle air compensator. A little valve on top of the throttle body that sticks or just fails with age. I had the same problem with my 96 contour, it's common with age. about $ 70. Don't forget to reset the ECM.
My bad I see you replaced the IAC, but did you reset the ECM Disconnect the battery works best for me.
I just thought of another stalling issue that cropped up about five years ago.
The O-Rings on the lower intake started leaking. First I got an engine light, Code rear bank too lean. Then it would not idle right and it started surging.
The dealer wanted $700 to change them, but I did it myself. Got to www.contour .org. They have photos.
http://img.photobucket.com/albums/v2...ushtony025.jpg Sorry..couldn't resist