Cleaning 94 Escort 1.9 Idle Air Control Valve?

solvent/cleaner

Got the same problem on my wife's '98 fiesta,took the IAC off ,but I don't know what I am looking at.Do these thing wear out,stick or what.

John

My F-250 stalls whem cold starting unless I keep my foot on the gas, and it sometimes stalls when coming to a stop. I had it put on the dealer's computer & it identified this part (the air bypass valve AKA IAC). They can be found online for under $50., but I wish I had tried to clean mine first. Try the carb cleaner & scrub with a toothbrush. Let us know...I think it will fix it. In the meantime, can anyone tell me where this part is located?

To answer John's question, they get stuck in the closed position & the engine is air-starved (yet fuel starved would have the same effect).

On my Escort its' contained in a small housing that looks like a thermostat housing just above the throttle plate pulley on the throttle body. Has an electrical solenoid/winding on one end, held onto throttle body by two small bolts.

Ifs function is to regulate the air supply to the throttle body with the main throttle plate closed, hence the term Idle Air Control Valve.

Going to work on it this AM - will let you know how I make out.

Chris Bowne Stonington, CT

94 Escort 1.9 LX 5 Speed, 133K 98 Volvo V70XC AWD Cross Country 117K 97 Taurus GL Wagon 133K with sick Vulcan 3.0-otherwise good conditon- for sale cheap!

What's the best way to clean it?Would putting 12volts thru it help, to make it move back and forth or whatever it does? As I said,I had a look at it,but I'm unsure how it works.Is it controlled by the ECU?

John

Well, a simple IACV cleaning made some improvement, and definitely changed things. Its generally holding normal idle better , seems to be slower than before responding to shutting the main throttle from speed. It still will occassionally stumble into a stall after extended low RPM idling at about

750 RPM, but a big improvement from what it was doing recently. At one point after the cleaning, it hung up at 3K RPM with the main throttle shut after an upshift. Didn't ever do that before. All I did was give a uick soaking spray in both ports with some WD-40 and some starting ether spray (couldn't find any carb cleaner in the garage, and there was a warning sticker on the IAC with the caution that it should NOT be cleaned due to a special finish on the internal throttle pate and stem assemby). It didnt look that coked up, but there was a definite coating of carbon on the stem and disc inside the body. May try giving it an extended soak in some carb cleaner (being careful to keep it from seeping into the solenoid stem) got nothing to lose by doing so - if that doesn't work I'll need to spring 60 bucks at AutoZone for a replacment.

Also replaced the PCV and associated vacuum hose bits, and put hose clamps on all associated joints - didn't make much difference though.

Chris Bowne Stonington, CT

84 Escort 1.9 5 Speed LX 133K 98 Volvo V70XC AWD Cross Country 117K 97 Taurus GL Wagon 133K with sick Vulcan 3.0-otherwise good conditon- for sale cheap!

Try here:

may bring it up to AutoZone's price; I didn't check that. I cleaned the one on my Escape a while back and it has worked OK so far (knock on wood). I used WD-40 and an old toothbrush, and rinsed it well ( with WD-40) before putting it back on. You can move the plunger back and forth fairly easily when clean. Don't use alcohol- it dries the rubber parts, causing to crack. Good luck!

SC Tom

yep, rockauto is where I got mine (about $50., including shipping). The part will be a generic; Airtex is the brand. I'd check ebay before ordering. There is one on there right now that would have fit my engine (grrrr!)

Good luck to all...this is a great forum!

Don't use carb cleaner. Use stuff espically made to clean IAC's that won't hurt it. They have this at the auto parts stores.

Removed the valve to have another look.The plunger moves ok. Must be the solenoid thats not working properly,but seeing as you can't dismantle it,how do I check this?

Check for voltage at the lead going TO the IAC valve connector. If there's no voltage detected, it's probably a bad TPS (throttle position sensor). If voltage IS detected, replace the IAC valve for maybe $50; cheap, if you really want to keep the car.

Since I removed the valve earlier today and moved the plunger up and down,the car has been ok.Went for a 10 mile drive with no problems.Maybe it was slightly sticking.

John

Well, the IAC is back to its old tricks, gotten steadily more "sticky" since I tried cleaning it with WD-40 last weekend. Will try a more thogough cleaning this weekend. Based on the (temporary) improvement right afterward, I'm encouraged that I'm working on the root cause of the problem, and its not something else like the TPS or EGR.

Chris Bowne Stonington, CT

84 Escort 1.9 5 Speed LX 133K 98 Volvo V70XC AWD Cross Country 117K 97 Taurus GL Wagon 133K with sick Vulcan 3.0-otherwise good conditon- for sale cheap!

I'd give it up and spend the ~$50 and buy a new one. From what I've read, if the problem reappears after cleaning, it's time to pitch the old one.

SC Tom

Yeah- you are probably right...won't cost much more than a full tank of gas to buy a new IAC!