need help air idle control valve

[Bruce A]

My daughter, who is a few hundred miles from here @ college had trouble starting the 2002 4WD Trac (100,000 miles) yesterday. Twenty degree weather, Trac has new battery. She mentioned that the truck's gauges read ok, but that it took about 4 tries to start the truck.



No problem at the dealer. He scoped it, nothing showing, kept it overnite to see if they would encounter the problem today.



This afternoon it took the dealer about four tries to start the engine, and he diagnosed it as needing the air idle control valve replaced.



I about dropped when she told me about $600 for the work if she has it performed, asked for breakdown:

$168 for air idle control valve

$42 labor

$65 diagnose

$68 reset computer

$44 fuel filter and labor (I had this done yesterday)

$200 injector and inductor cleaning (This is the one that I really question)



I had her ask about this last item and he replied something to the effect that sometimes the system gets carboned up when the idle control valve goes out, but that the cleaning could be done later.



I would appreciate anyone's 2 cents about :

-The diagnosis. Is the air idle control valve something that normally goes out at about 100k miles, and is hard starting a symptom when they do go out? Does a scope positively point this out?

-The carbon/ cleaning issue

Can't imagine $200, but I'll listen. Is this something that Regane or Seafoam can clean up?



The Trac has overall been a good truck, and has received great care & maintenance. I may sell it soon.



Thanks all.

 

[Christopher Comeaux]

the last one i think can be done with seafoam

 

[EddieS'04]

The injector cleaning was BS. The IAC was 3 times to much, even for fords parts. Motorcraft fuel filter $8 to $12 dollars at any auto-parts. The diagnose and reset cost should have been removed from total bill, since they did the work. My dealer does.



Since it was a woman they ripped her, bad. I would raise He%%.



The IAC is not checked with a scope. The circuit and the IAC is checked with a simple VOM.Most likely it was only dirty.



If you suspect the IAC. Just hold the throttle down on starting. If it starts it is the IAC. I would have suspected a weak fuel pump. That year had problems with bleed back. Bad check valve. Loss of line pressure after sitting. If she has to get a pump next. You know she got ripped.

 

[Brad Schultz 2]

Is there not a base idle screw on the throttle body that can be used temporarily to raise idle speed?

 

[EddieS'04]

Is there not a base idle screw on the throttle body that can be used temporarily to raise idle speed?

Yes but that is not its purpose. The design of the TB is. The screw is set at a specific measured throttle plate gap. The feed back loop of the RPMS and TPS to the ECU, controls idle with the IAC.



You can adjust the screw, but. You need to measure the TPS voltage. Make sure it stays below 1vdc at closed throttle. Actualy you have a very small window of throttle increase with the screw. The ECU is programed to idle @ 750rpm. The ECU will try to keep that @ 750 with the IAC.



I increased my idle to 800rpm. It had to done with my xcal 3, computer flasher. I had Torrie write it into my performance programs.

 

[scott degroot]

The proper way to check IAC operation is with a labscope. That is the only way you can see what is actually going on with it, problem is the dealership I'm sure is calling the scan tool a scope. This isn't really a bad thing as the Ford IDS scan tool has info on there that shows the amp draw of the IAC but it still does not show you what the actual circuit is doing.



I have a question. Does the truck ever have an idling issue at any time?

 

[Dreman]

As for the question of how often they go out...



I had mine replaced under the 36/36 warranty at 35,750 miles! Then no one has touched it until a few weeks ago, when I took it off and cleaned it just because, at about 250,000 miles. Untouched for over 200,000 miles without an issue.

 

[Ed Fenwick]

Gee, I haven't looked at my truck, but on a seville some time ago, I just took it apart and cleaned it. Electrics you know go funky in the humidity. Seafoam does do wonders for the fuel syatem also. Good luck Ed

 

[Bruce A]

Thanks for the responses!



She reports that Thurs. it took 3 times to start, and that was unusual.

Friday it took 3 tries. She reports that after the 3rd try it started and the tach was jumping & the 'check engine' was on. She turned it off, restarted it after a couple of tries and it worked fine.



My concern is really twofold. First off, I want to be certain that the dealer has made a bonafide diagnosis and is pretty certain that it is the air idle control valve. I know a fuel pump will be pricey, if that's what it is, and this was my immediate concern when she described the problem. I'm trying to avoid two expensive fixes if only one is necessary.



The second concern was stated in the original post, that is, the cost of the work quoted. When I heard the cleaning and diagnose/reset charges I got pretty hopped up and thought I smelled a ripoff. Thanks for detailing the crime, I have a few more talking points.



My priority is to get the right fix, reasonable price is the next objective. Is it pretty simple to positively diagnose a bad fuel pump if that is the issue? I wouldn't want the truck going down on a long trip.



Thanks all!

 

[scott degroot]

The next time she goes to start it when it's cold have her turn the key on for 5 seconds(don't start it) and shut it off for 5 seconds. Repeat this 2 additional times and then try to start it and see how it starts. If it fires up normally then there is a good chance that the fuel pump is bleeding off pressure while the vehicle sits. The procedure above will repressurize the system. As Eddie stated above pushing slightly on the gas pedal will help to determine if the IAC is suspect or not just make sure not to give it any more than 1/4 throttle..



The fuel pump is very easy to diagnose even if it seems to functioning properly but it is amazing that probably 95% of the techs out there don't have a clue how to do it.

 

[Todd Z]

We called this the sport trac gremlin..... IT seems to happen to almost every ST 1 or so times in its life...



We have found cleaning or replacing the IAC has fixed 99% of the trucks that this happened to...



Just too common here not to say that... i know others have seen different and its not "allways" the case but like i said on this board is the IAC



Todd Z

 

[Bruce A]

 

[Bruce A]

Thank you for the tips! I'll have Daughter perform the tests with the gas pedal and key.



I really appreciate your help, what a great bunch you are!