Fuel Filter or IAC?

[maverick]

Hey guys, Basically when it rains or sometimes when its cold outside my car has trouble starting. Now SOMETIMES if I give it some gas the car will start and stay on. I called a ford dealership and a mechanic suggested my Idle Air Control Vavle needed to be replaced. I have read some threads here and it sounds like what is going on. An autozone guy suggested though that it could be a fuel filter problem if by giving it gas it will start. The other thing that happens is that I receive a humming sometimes like while idling at a light. He told me the IAC would not hum, but I didnt really believe him after reading many posts on this subject. So i feel the IAC will need to be replaced, but would it be worth trying to replace the fuel filter? thanks so much everyone
-sean

 

[mikeh]

You can put a fuel pressure tester on the shrader valve on your fuel rail to give you the PSI. It should be 30 or more PSI. That will tell you if you are getting gas.

My guess is that it is the 00M12 TSB. Do a search. I fixed mine myself. This fix is related to cold start problems

If you have the problem all the time the other possiblitliy is the IAC. To test the IAC pop your hood and disconnect and connect the wire to the IAC to see if it makes a difference.

mikeh

 

[maverick]

did this every happen to you after it had rained? you are referring to the car having problems starting correct? and not the whining?
thanks
-sean

 

[TPLYNCH]

Whining/moaning at idle is a symptom of the IAC going bad. You can try cleaning it first and see if that makes a difference before replacing it. Fuel filter should be replaced every 15-30K miles. If it hasn't been replaced, then I would do that too just as a general maintenance issue.

 

[maverick]

what can i clean it with? earlier when i had called a ford dealership and they told me about the IAC possiblity, they said it could not be cleaned...i'm assuming though they said that in hopes i would buy one from them. WD40 or something different? Toothbrush?
thanks

 

[TPLYNCH]

Read how here. Use Search and you will find http://www.explorerforum.com/forums/showthread.php?t=84220&highlight=cleaning+IAC

 

[maverick]

thanks TPLYNCH, that thread seems like it will help. Have you had a problem like this before?

 

[TPLYNCH]

My IAC had the HUM. Never had the idle issue with it. Problems with the IAC seem to be fairly common with the '97+ Explorers

 

[maverick]

i cleaned it yesterday with some quick dry electrical cleaner, just sprayed inside of it, let it dry for an hour so, wiped it out. Put it back in, heard a little hum as I was coasting down a hill but maybe it wasnt completely dry. Going to take it out today and see what happens. Did cleaning yours fix the hum or did you end up getting a new one?

 

[TPLYNCH]

MIne was replaced. Had about 100K on it at the time, and decided to just change it while having tunup done

 

[urbanistic]

Read how here. Use Search and you will find http://www.explorerforum.com/forums/showthread.php?t=84220&highlight=cleaning+IAC

You really cant clean an IAC. If you do, fluid (or whatever you use) will be trapped it he rubber spring boot, it wont work properly afterwards. You might as well superglue it closed after cleaning it. The best way to clean carbon or build-up from the intake is to run a motorvac on that guy. Even then, you still may need to replace the IAC afterwards. I suggest a 30$ OBD1 test first.

 

[urbanistic]

I bet your problem is a bad IAT and Purge Solenoid. The purge solenoid controls warm air to the engine on initial start. No warm air = rough start. Also, I bet your fuel filter is getting blocked, test the PSI. 3rd, check the vacuum tubes. If you need a layout, let me know.

 

[maverick]

there wasnt really any dirt anyway in the thing the IAC still works. The sound came on when I started the car just long enough for me to pop the hood and listen. I swear it sounded like was coming fright from the air filter box and NOT the IAC area. I put my ear right to the box and heard it, then it went away. Its raining outside right now, going to go and see if the car will start.

Urban: isnt the code scanners mainly for if the CEL is on? Mine is not
Also, what is the IAT? You are referring to my rain problem correct? I really appreciate all the help guys. How can I test the PSI of the fuel filter...or I guess rather the lines going to the filter? thanks!

 

[urbanistic]

For your first question, if you want to test the PSI coming from the filter, downstream from the filter to the engine, there is a a testing point for that. The flow goes from the pump to he filter, then to the pressure test point, then to the injectors, to the regulator, and then back to the tank. Test the PSI at this point. ll you have to do to test is to plug on the PSI and then turn the key to the on position. The pcm tells the pump to run, and if the starter doesnt fire, it turns off in like 1.5 seconds. Thats all the pressure time you need for a reading, but I suggest turning the key 3 times. It will not make the pressure higher. You should readbetween 35 and 45 psi, which is spec. ou can also hotwire the rightside pin on the connector for the ODB1 tester. with the angles upwards while looking at the connector, short the right side slot to the vehicle ground and your fuel pump will stay running when you turn the key on.


he IAT is the intake air temp resistor sensor. Lets the pcm know how cold the air is. Hearing a better desc from you, I would advise to pull the whole air intake system out. The black tube to the box, then the box, then the vent connected to the box. There is a tube which brings warm air from the engine to the box, and it has a valve control which will keep the vent open from the engine if the IAT is bad. You can ohmmeter the iat to see if its bad... I can explain that later. Check the foil tube from the engine to the lower arm of the intake... it brings air from the grill to the bottom of the filter box. Check for debris. Oil the valve in there LIGHTLY. If you hear noise from the box just when you start, it may be that valve not working. The Purge Solenoid controls the movement of that item and that should be checked too. See if the T on the end of it is clogged with goop. If it is, replace it and the vacuum lines to it. The Purge Solenoid is the only component inbetween the air intake manifold and the engine block, and it is visible from the drivers side of the engine, just below the IAC area.

 

[urbanistic]

If you have a 2000, im sure yours is obdII... sorry about that.

 

[maverick]

thanks for the lengthy response. I have a feeling the fuel filter is a little clogged because as soon as I put in some fuel filter cleaner thanks to this wonderful guy at AAP, I havent had the problem all weekend. This weekend I am going to try to replace the air fuelter anyway because it is a lil past due. The cold start problem may be solved now still hashing out the idle noise. Urban how hard is it to completely take out the air intake system? I dont want to really screw something up...Just removing a few nuts and bolts here and their? The weird thing is that when I start it sounds like its coming from the box...but then there is all this talk about the IAC and honestly its hard to figure out exactly what to do. I appreciate all the help Urban!

 

[TPLYNCH]

there wasnt really any dirt anyway in the thing the IAC still works. The sound came on when I started the car just long enough for me to pop the hood and listen. I swear it sounded like was coming fright from the air filter box and NOT the IAC area. I put my ear right to the box and heard it, then it went away. Its raining outside right now, going to go and see if the car will start.


When the IAC is bad and whining/moaning, it sounds like it's coming from the air intake. If you open the air filter box when it is doing it, the noise will be alot louder. If cleaning the IAC didn't work, you can replace it, or just live with the noise.

 

[BuffaloXplorer]

The sound came on when I started the car just long enough for me to pop the hood and listen. I swear it sounded like was coming fright from the air filter box and NOT the IAC area. I put my ear right to the box and heard it, then it went away. Its raining outside right now, going to go and see if the car will start.

I has a similar noise that has since gone away. Almost like a howling, but from the airbox. Mine would last until i drove 30-50 yards or so. It'll come back on occasion, but not frequently. Not sure what it was/is.

 

[TPLYNCH]

Chris, if it happened when it is hot out, that is the IAC. Doesnt happen as much when temps get cooler.

 

[BuffaloXplorer]

Thanks, Tom, for the info...if i remember correctly (tryin to think when the last even remotely HOT day was in Buffalo), when it last happened it was probably considerably warmer than the current 50deg., and the sound started and occured more frequently during the summer.

Will cleaning it now, even when the temp is not nearly warm, help? I'm assuming that if there is a problem when it's hot then there is likely an "unheard" problem when it's cold, right? I think i'll clean it...

How likely is it that this is a significant contributor to my horrible gas mileage issue?