5.4 engine, 75K, I had some random non-starts in the past couple of weeks (it would start like a champ but drop idle and shutdown after only a couple secs), but once it finally held idle after 4-6 cranks of the ignition and by me putting a load on the pedal it ran like a smooth machine. So last week I took it into the shop, they said the FI's needed cleaning and that would clear it up, after 1 week of having the FI's cleaned I have the same results again. Right now these guys don't have a handle on it (I took it back up there last night and they said it starts and runs fine, no re-occurances of the problem or any error codes in the log). Any suggestions? The vehicle runs great but I don't trust it starting everytime like it always has......plus it also has a small 'roughness' to the idle since they cleaned the FI's, that roughness wasn't there before.....??? I dunno, anyone got anything before I take it into the dealer....

Thanks,

 

Usually, this problem is symptomatic of a bad/carboned-up IAC (Idle Air Control) valve. Search this forum for "IAC valve replacement" for more info.

 

I have exactly the same problem, only occurs at times. I thought at first it may be in the linkage to the throttle body.

When I start up in the AM and it doesn't hold idle, I hold the gas down to about 700rpm's and drive for a few miles and it corrects itself.

If you find out the problem please inform me, I thought once that it may be the gas cap I replaced ( a locking one ) if you push the cap in when you replace, a vacuume is generated in the gas tank... don't think this is the problem.

I have a band-aid you may want to try until resolved..push the gas pedal completely to the floor before starting each morning then release. (On start up the 5.4L tacs about 1200rpm's then drops down to around 700 automaticaly and holds.) One day it was acting up I kicked it into passing gear on the expressway and it seemed to fix it for a few day's then came back...

Let me know if you find the culprit OK?

cobrah

 

Replace the IAC. Common problem on the Ex. Use the search feature on the site and type in IAC valve or IAC solenoid. It should give you all the infor your looking for.

 

All,

Thanks for the advice, The IAC will be replaced today. I'm curious, I have asked for the shop to save the IAC that is coming off of the engine, does anyone know what I might expect to see as far as buildup inside of the part? (color,density, characteristic's)...

thanks,

 

Carbon - black soot, possibly some encrustation.

 

i got on this forum today to find out the answer to this exact problem, my ex hasn't done this for a while. It was happening to me quite frequently until i had the fuel injectors cleaned out, but it did it tonight and i was frustrated.. i'll get a new one. hope it's not to hard to put on.

 

All,

I had the IAC replaced and then took it on a 1200 mile r/t to FLA from ATL over the weekend, I did not have one reoccurance of the problem until I was about 300 miles from coming back to ATL yesterday (about 900 miles into the trip), then when I pulled off of I-75 to get fuel, the engine just cut off right as I was pulling into the gas station (I coasted in). I filled the tank up and the engine restarted without any hesitation...I'm just wondering what might have caused this to happen ???, any ideas? needless to say I was waiting for it to happen the rest of the trip home....not a good way to drive.....

 

how much gas did you have left? Sounds to me like you ran out of gas or possible vapor lock. Some of the gas gauges on these things don't read like they should.

 

I still had about a little less than 1/4 of the tank left, so that shouldn't have been it...but the vapor lock interest me...how would that have occured?.

Here is what happened:
I stop at just about every rest stop (black lab with a leaky kidney travels with me) on the interstate, so I figure I had just driven about 50-70 miles before I pulled off at the exit ramp, I had the AC on low and had a little less than a 1/4 of 87 octane in the tank. I stopped at the stop sign, turned right and went about 50 feet then it cut off, I coasted into the station the rest of the 50 or so feet left, I dunno what happened, it just cut off on me...I'd like to know more about the vapor lock scenario?, my neighbor says I should look seriously at replacing the fuel filter and fuel cap?, what do yah think ?

So far I have had the throttle body cleaned and the IAC valve replaced and the failure to idle at startup has vanished, but this cutoff thing is something different.

Oh yeah..the Check Engine Light did come on when this happened......

thanks,

 

I am having what sounds like the same problem, infact I just posted yesterday about the problem, under "problems starting-strange" Have any of you noticed anything in particular about when it does it, like right after it rains or after you wash it.? I swear, mine has done this like 4 times in the past 3 weeks and twice was the morning after I washed it, ( washed it and put it in the garage). then the next morning it does not want to start, it will try and just stall out, but once you get it going it seems fine. The other 2 times was right after it rains samething,. We were just at the beach for a week and the first 2 days or so it rained and it did it just about everytime I started it up and when the sun finally came out and dried everything up it ran fine the rest of the week, not one single occurance after that until I got home and thought I would experiment, so I got the hose out and soaked the whole thing down for like 15 20 minutes, started right up, put it in the garage, and the next morning, guess what, same problem, did not want to start. I really want to make an appointment at the dealer to get this fixed, but I know it will be one of those things that it won't do it for them, very frustrating, other than that I love this thing. Let me know if anyone finds out whats up. Thanks Brian

 

Brian, your problem sounds like the classic GEM module getting wet. These things are notorious for leaking water through a drain hole in the firewall right onto the gem module. I'd check there first. Sounds about right to me. I have seen people silicone the hole with great results. Good luck and let me know how you make out.

Blacjack.... I would start with your fuel filter. If your cap was bad it would throw the check engine light. Is your light still on? If so take it to Auto Zone and have the codes pulled. This will let you know what is going on. If you do change the filter then you will need a Ford filter removal tool. It is available at Advance, NAPA, and auto Zone for about $5. Pretty simple to change. It is located on the inside of the drivers frame rail right under the doors. It is round and about 3" in diameter. Let me know how you make out also.

 

the4by4freek, thanks for the reply. Hate to sound totally stupid but what is the GEM module and where is it and if the drain hole is siliconed closed will that create someother problem cause it is plugged shut? Hope I can find this hole, I would really like to fix this problem myself without taking it to a dealer. Again, thanks for the help . Brian

 

I'm not seeing how that can help. Opening the throttle body does absolutely nothing with EFI. No choke to engage, no carb to squirt gas into the manifold. It's all electronic......

Yeah! What's a GEM? I think he must mean EEC or ECU..........

 

The ECU is inside the passenger compartment under the passenger side kick panel. This is not what I'm talking about. If the ECU were getting wet so would your carpets! The GEM is an electronic module that controls all kinds of different electronic items in the truck, almost like the ECM controls the engine. There was a thread on this site that covered this problem. It had pictures and all! It went into detail on what the truck was doing and it was always after it rained. The hole is somewhere in the cowl over the firewall. As far as I know there was no reason for the hole and it was short circuiting the GEM. I don't have this problem personally but there were a bunch of people that did. The only water problem I had was that Ford sealed the drain tube for my sunroof shut. It was right where the tube exited the floor board. It was full of foam sealant that they used to sound proof the truck. I had to replace the entire tube from the sunroof to the floor! This is another fine quality Ford screw up! Your hole is about the same way. Good luck.... use the search on this site for GEM Module. This should give you the answers you need.