I was wondering if some one could help me with my wifes truck?It is a 99 explorer 4.0 sohc automatic. She said it was hesitating so I new the air filter was due to change so I changed the air filter and replaced the plugs at the same time,the next morning she calls me on her way to work and says its no better!So on the week-end I changed the fuel filter, still running poorly!
Thought it was in the transmission so we took it to a shop,he called that afternoon saying there was nothing wrong with the transmission. Stopped at auto-parts to see about diagnostic check but he wouldnt hook machine up since check engine light wasnt on! Refered me to another shop but also said if it was a fuel problem diagnostic check might not show nothing. So today I put some b-12 in the tank and fuel and went to the high-way to blow it out!!!
No better truck idles at 1300-1500rpm
in nuetral 1800-2100rpm Truck hesitates at 45mph
Truck is running alot hotter than normal
Any ideas??? Thank-you for your time Marty

 

Could be a number of things....have you changed the thermostat? Check all of your fluids. How many miles are on it?

 

89000 miles, all fluids ok ,havent checked thermostat yetMarty

 

Well, most of the time, when they're running hot, the thermostat seems to be the problem. When you replace it, make sure you get a new o-ring for it...these don't have gaskets like most.

If that doesn't take care of it, then you're looking at either a fuel system problem or an engine control problem.

 

You're idle is WAY too high. My 99 X idles at 650 in drive and 700 in Park/Neutral. I would consider looking into a possible intake manifold leak. There is a TSB out on the manifolds for this engine. I had a rough idle problem that never generated a CEL. There was a code for a lean mixture in Bank 1 and 2. So it is apparently possible to have a stored trouble code and not have a CEL come on. Anyway, my manfold O-rings were replaced and solved my problem at 35,000 miles. Your's may be more advanced given your higher mileage. I hope this helps.

 

Yes I Know the idles too high,the more I think about test driving it friday ,it was fine until it warmed up,so friday nite I stopped at the auto parts store for a thermostat like Jonm 61 said,got home tore truck down and learned the boy gave me the wrong thermostat!!! So now I have to wait for my wife to bring my truck home so I can return the thermostat!

 

Well its been over a month now and my wifes truck still isnt right.
Took to ford dealer they ran diagnostic check,and said the only thing
that was wrong was 2- cracked plugs,I had just replaced them,and in all
my years of shade tree mechanics dont remember cracking a plug much less
2, worker said they probably were dropped at the store.
So remembering the time it took to change the passenger side plugs I let them
do it.After work was done they re-ran d-check and said truck was ready!
started fine that afternoon at the shop,the next morning my wife calls saying
shes at the house truck wont stay running.so I get home take it back to the shop they keep it 3-4 working days including week-end,so I call monday they say its ready ,they stopped and started it twice a day while they had it!
Foreman reset computer and kam (no charge).
Tuesday morning my wife calls me truck wont start!!!!
So she calls and chews them out now they want me to be there to show me it starts for them! But I cant get truck to stay running may need to tow it to shop$$ Basicllytruck wont idle,have to use gas pedal to start but dies when released. heard popping sucking noise by air cleaner area also I do not here fuel pump like I used too.Could the morning moisture be getting to something?
The spark-plugs did fix the high-way speed
But truck wont start and idle at times mostly mornings
My wife asked them at the shop about the fuel pump,and they said every thing is electronic or computerized and that the diagnostic check would pick up any problem. When it gets back to the shop im sure they will run another d-check I asked for a print out last time but they didnt have one.can errors not show up or be hidden ?
ANY IDEAS???
mARTY

 

If it's mostly hard to start in the morning, drop it off the night before & then show THEM that it won't start in the morning.

As for the diagnostic, if they clear the codes & they don't immediately show back up, then it will look like it's ok.

 

Hey thanks for replying Theyve had the truck with no pressure over 3 days and they tell me they started it in the mornings and evenings every day they had no problem!!! The service advisor brought it around the building for us to take monday night. Tuesday morning it wont stay running!
The main problem now is:
Truck will not stay running with-out applying gas pedal(including starting)
I ease off gas pedal and truck dies

The second time it didnt start I revved it up like you would a carb-motor to clean it out ,and it got me to the shop with a good idle with out using gas pedal and truck never died.
Marty

 

Have they checked the vacuum system?

I had a similar idle problem with my '94. Turned out to be the computer, as it monitors and adjusts idle speeds.

 

Also check this.

https://www.ford-trucks.com/forums/s...d.php?t=166103

 

It does sound like a vacuum leak. I had that problem, but I caused it, so I was able to fix it quickly & easily, once I realized that I hadn't tightened one of the intake manifold bolts all the way. Also, maybe a fuel injection induction service would help.

 

Thursday morning I was calling on prices for towing truck to the shop,because I didnt want to drive it using gas pedal and brake and get to the shop and the thing starts up and idles because I cleaned it out driving it.
I kept thinking about Backin72 response and link he had posted,so I went out removed the plastic cover over intake,used the ratchet to tap on the iac valve and the darn thing started and idle fine!Removed the iac valve cleaned it up for now and vehicle is back on the road!!!

Auto-zones web site shows $39.00 for the iac valve

I was upset I paid a $110.00 for a diagnostic check that they assured me that if there was a problem it would show,now granted if I wouldve took it in they may have found the problem(third times a charm)and wouldve paid there price and labor.
Im deciding if I should call them and let them know that a non certified mechanic fixed the problem,because then they will want to know what I did and Im not sure if I want to tell them!!!
Or im thinking about asking them for a application
Any-way thanks again Backin72
Marty

 

Ahhh, it's a beautiful thing when it works out! I'm glad that I was able to point you in the right direction, but ya really gotta thank this site and all the great people that contribute to it through their experiences and knowledge.

I've read a lot of stuff here and your problem sounded familiar, so I had a hunch of what was going on. You should familiarize youself with the stickies on the top of this board, tons of useful info!

As for the dealership, tell them you got it fixed for FREE on the internet!