Need suggestions

[grefra]

I have a 1998 Explorer Sport, 4.0 SOHC.
I am stumped. The truck was ideling bad and running rough. I took it to the local Ford dealer and they suggested a tune up. They replaced the spark plugs and the fuel filter and said the fuel filter had restricted flow.
Thought all was well, but no.
Ran bad still, returned to the dealer and now, the IAC needs to be replaced, OK, did it. I am in to this $400 so far and it still runs bad, when in drive, stopped, foot on the brake, the truck dies.
I am thinking the dealer is a parts changer, and at my expense.
What else could the problem be??
Thanks

[99f350sd]

1st off I would have them put the old IAC back on and see if it runs any different. They really need to stop changing parts and diagnois the darn thing.
It must have run ok if they gave it back to you the first time??? So the problem is not happening all the time?

[grefra]

It does happen all the time. It happened as soon as I got the truck back, which was last week.
The old IAC which I kept is either really carboned up, or actually looks rusty inside.
I guess I will take it back, for god knows how much more it will cost to either put it on a scope or diagnose the problem and get it fixed, The truck only has 58,000 miles.
My neighbor has a little, big dollar diagnostic machine(hand held), I will see if he can check it and find out the codes.
Thanks

[99f350sd]

When you first brought it in they are supposed to diag the car..They did they said it needed a tune up WRONG wasn't the prob. They then should have diag the car again...said it needed an IAC Wrong Diag again...get your money back or take it to a diff dealer..I never pay for wrong diagnosis ,they are the dealer!!!!!!!!You bring it there cause they are the pro's ...You could of had your neighbor change parts...

[grefra]

Originally Posted by 99f350sd

When you first brought it in they are supposed to diag the car..They did they said it needed a tune up WRONG wasn't the prob. They then should have diag the car again...said it needed an IAC Wrong Diag again...get your money back or take it to a diff dealer..I never pay for wrong diagnosis ,they are the dealer!!!!!!!!You bring it there cause they are the pro's ...You could of had your neighbor change parts...

They have never diagnosed the truck. I am sure if I take it back and tell them I want it diagnosed since the $400 already spent didnt do it, they will charge me for the diagnosis.
Problem is the next closest dealer is 50 miles away/

[99f350sd]

I guess you are on your own...Give more info and we'll try to help if we can..

What does it do? how often? how long does it last? Everything...

[marragtop]

Check for vacuum leaks and get the codes pulled. There could be codes stored even if the CEL is out.

[Bear River]

The tune up was wrong, thogh it was probably not a bad thing. They said the flow was restricted? I suspect there may be water in the fuel. Water in the fuel and clogged fuel filters often go hand in hand. Was the truck run out of gas or run lower than usual lately?

Pull the codes as a starting point, and then approach the problems that can cause a misfire. The IAC will never cause a misfire, though it can cause a rough idle. I would suspect the MAF sensor may be the problem, clean it. Next suspect would be the O2 sensor, remove and inspect. If it is light grey or tan, all is well, but if it is black or has any kind of deposits on it, replace it. Vacuum leaks will cause a misfire since they confuse the computer.

[grefra]

Originally Posted by Bear River

The tune up was wrong, thogh it was probably not a bad thing. They said the flow was restricted? I suspect there may be water in the fuel. Water in the fuel and clogged fuel filters often go hand in hand. Was the truck run out of gas or run lower than usual lately?

Pull the codes as a starting point, and then approach the problems that can cause a misfire. The IAC will never cause a misfire, though it can cause a rough idle. I would suspect the MAF sensor may be the problem, clean it. Next suspect would be the O2 sensor, remove and inspect. If it is light grey or tan, all is well, but if it is black or has any kind of deposits on it, replace it. Vacuum leaks will cause a misfire since they confuse the computer.

We are going to get the codes tomorrow and I will post back. I already removed and cleaned,(looked spotless) the MAF/ What and where is the O2?
I have not ran out or low on gas ever since new. The check engine light came on last winter, I removed the negative battery terminal and reconnected, hope the codes are still there. Will a code show if it just dies without the check engine light coming on?
On the road the truck runs great, smooth and 20mpg at 65 mph without a/c.
Wow so many hoses and lines, I will try to figure out vacuum lines and if any look bad.

[grefra]

Originally Posted by Bear River

The tune up was wrong, thogh it was probably not a bad thing. They said the flow was restricted? I suspect there may be water in the fuel. Water in the fuel and clogged fuel filters often go hand in hand. Was the truck run out of gas or run lower than usual lately?

Pull the codes as a starting point, and then approach the problems that can cause a misfire. The IAC will never cause a misfire, though it can cause a rough idle. I would suspect the MAF sensor may be the problem, clean it. Next suspect would be the O2 sensor, remove and inspect. If it is light grey or tan, all is well, but if it is black or has any kind of deposits on it, replace it. Vacuum leaks will cause a misfire since they confuse the computer.

Would you drain the fuel tank and just try a gas drier??

[Bear River]

No, just add a gas dryer, no need to drain the tank.

The O2 sensors will be either in the exhaust manifolds, or on the headpipes behind the manifolds.