Lately I seem to have developed a problem with my 99 Exp w/5.4. It starts fine when cold but a couple weeks ago I noticed that when the engine is warm I have too crank it over much longer than when cold 5-10 sec, it does start but I'm trying to be proactive. Truck has about 130K on it and plugs were replaced a few months ago.

Thanks for the help.

 

Most of my issues on my 2000 stem from when it's cold out, so I'm not sure these would apply. Personally I would start with the IAC and clean it out. I used some PB Blaster, and a nylon brush while avoiding the rubber o-ring internally. Possibly the MAF sensor may need to be cleaned as well. Only time I have hard starts when it's warm is during high humidity, and of course a truck that can't get out of it's own way under those conditions. Something would be expanding with heat that could cause this, as opposed to contracting in the winter where my issues spring up<-No pun. After that I would check EGR and Fuel pressure. Since it's a 99' and has 10K less miles than mine, when was the last time the fuel filter was changed? Also when starting the truck, have someone listen for a tick coming from the engine after it starts. It could be the sign of a clogged injector or a stuck lifter. Lastly I would say the starter, but it seems unlikely. Also when putting the truck into accessory from letting it sit, you'll hear the fuel pump engage momentarily before starting, like a slight hydraulic sound. Listen for that next time as well.

Going back to my expansion comment, and the IAC that rubber o-ring or it my be Teflon, could be expanding when it's warm. So the plunger that controls air flow needs to create friction in those few seconds. I would deff start with the IAC and clean it out. You can hit it with WD-40, Seafoam Deep Creep or Mineral Spirits, and let it soak for a bit. When I did mine I let it sit and whatever I sprayed in, came out of the IAC damn near jet black. That's how dirty it was. I hit it again, and without soaking just brushed out what I could avoiding the o-ring. The difference in pushing the plunger down, was night n day by hand. I clean it out every summer now.

 

Thanks for the tips, doubtful it's the starter as cranking is not a problem. However where do I locate the IAC sensor, is that the one behind the air filter? And the Fuel filter has about 15K on it, will be changing that tonite after work.

Also the only code it's showing is P1000 which is odd because I've driven over 500 miles city/highway since the Bat was last disconnected.

 

That code from what I found is "OBD-II Monitor Testing Incomplete" you would need to clear the code, and then drive the truck for about 30 minutes, no stopping and turning the engine off, of course you can stop though. Pulling the Neg on the battery for about 5 minutes to make sure the code clears. I say this since I found out it takes 1 min to disable the Air Bag system after a battery is disconnected, so it led me to believe everything else follows after. If the code comes back, that's where I'd say have a Ford Dealer run a scan.

Your IAC is here http://mattstruck.com/iac54.jpg

On the 5.4L it's a pain to get to but can be done. I have a 4.6L which made life easier. But it's only 2 bolts. I believe they're between 10-14mm, but don't quote me, I forget exactly. In your case a ratchet ended wrench vs. an actual ratchet may help here. And like I said if you do plan to brush it out a bit, avoid the o-ring.

 

You could try replacing the coolant temperature sensor. If it's faulty as I suspect then the ECM is not sending the correct air/fuel mixture to the engine. A bad CTS will also cause a code 1000 because some tests will not complete if the engine doesn't fully warm up. Even though the engine is fully warming up, a bad CTS is making the ECM think otherwise.

 

Alloro there you are. Was hoping you would give some advice. I always learn something when you comment.

 

Thanks for the input, I just changed the fuel filter. Wish more things were as easy to do. I'll run over and get a CTS and install that too.

 

Can't find the CTS were is it located on a 99 5.4, it's not on the front of the intake behind the alternator?

 

Mine being a 4.6L is located on the rad almost. It's coming off a metal cooling line on the left hand side of the rad at the top. Right next to the washer fluid.

 

Well think I found it, not even close to where the Chilton's says it is on the front of the intake. Nope under the intake drivers side, maybe I can get it if I pull the alternator otherwise the intake has to come off to get to it.

 

I think the CTS is in the center of the intake manifold, directly below the throttle body air intake.

 

 

sorry svchareta not even close, not sure which year/engine that pic is from but it looks nothing like mine.

 

My apologies. I looked up the part on Autozones web site, and that was the picture they had in the auto repair section for the 1999 expedition Coolant Temperature Sensor. I did not verify the picture against my 1999 expedition.

 

No biggie, that's were my Chilton says it is too, NOT.