Hey guys,

Here's the history in short. Bought used in '04 with 97K miles. Currently 228K miles. This truck was not started and garaged from November of '09 until June of this year. I had trouble with it draining the battery dead (battery light would flicker). Did LOF and routine maintenance check prior to starting again this past June. When truck was started, it run rough and missed some until computer reset itself. A/C clutch had to be pulled and cleaned up to regain proper air gap to engage compressor. Removed the remote starter system and battery drain issue resolved. Prior to being garaged this truck seemed to lag in shifting out of OD at lower RPM's while pulling my trailer.

Fast forward - rings must have set up a bit while not driven. Puffing a bit of smoke at startup and using a bit of oil. Previously didn't use any between 3k mile changes. Truck is now getting close to 6k miles since being driven again (3rd oil change since being brought back out). Can still feel light missing, intermittently, while driving. I have cleaned throttle body and added Seafoam to tank and sniffed it through vacuum line.

Just recently began to idle fast - at start up drops to about 800. While driving down the road now, if you shift into neutral - idle is between 1300-1700 RPM's. Stays there until you come to a complete stop, then drops back to about 900. Also while cruising/coasting (no acceleration or deceleration) at 40-45 mph if you begin to accelerate, trans acts like it doesn't know which gear to engage. It may downshift or may not. No codes at all with my MemoScan device.

Plugs and boots changed 40k ago. Plan to pull plugs, drop 2-4 oz. of Seafoam down each hole and let soak for a few days, then install new plugs and boots again. Hoping this will free up any stuck rings and miss issue.

Not sure at all about this fast idle and/or trans issue! That is where I need your input guys. Feel feel to give advice on any of the issues I have listed here and I apologize for the long-windedness!

Thanks...

 

....First this is not meant to be a lecture but the truck does have a large amount of mileage drive time.
....I would not put a lot of faith in Seafoam to clear age related issues.
....If the truck had the use of modern oils and changed often enough, there should not be any stuck ring issue like years ago.
....Next the throttle control is electronic and not the usual IAC control of the earlier trucks. So you need to be awhere of trying to correct idle on that system.
....Next, the TPS/throttle angle 'function' has a large effect on transmission shifting.
....Next, I would believe you might have at least one faulty ignition coil causing some drivability issues in OD at light throttle cruise and may not show up as a code to ID the cylinder.
....Bottom line is mutiple issues you have to work out.
....The electronic throttle control is not an area you should get to involved in unless you are familuar with how it works.
....Electronic throttle is a subsysterm of the PCM.
....It has it's own micro processor and takes instruction from the PCM as well as sends your throttle request to the PCM via a seperate communications bus.
....There is fail safe programming involved so throttle faults can't run away with you and have no control except to shift into neutral and turn the igntion off
....Aside from the possible coil issue, look for codes with a scanner capable of reading the 'CAN' version of OBDII, not the 03 and earlier version.
....If you see an issue with the electronic throttle it's dealer time.
....IAC and TPS issues you might be able to service them with care about the relationship to the electronic throttle operation.

....Normal cold start is to raise idle speed depending on how cold the motor is then come down to about 750 +/- and be stable at that point.
....Accelleration hesitation is a normal thing with these early systems.
....I would not call it a malfunction but it does not work quite like we would like it to.
....There are software fixes but don't know if a dealer can help you without going aftermarket using a tuner/ program.
.
Good luck.

 

Thanks Bluegrass,

I get the impression you feel Seafoam or any other agent is a waste of time when I change the plugs? I figured changing the plugs and running a compression test would help me to find which cylinder(s) are problematic. A starting place so to speak. This truck did not use or burn any oil prior to being garaged so I felt stuck oil scrapers resulted from the long sit time and didn't figure it could hurt to try this approach.

I have a client who within the last 6 months purchased a new "state of the art" scanner. He is on board to use such on this truck. I have not talked to him since this idle issue came up. Do ya'll feel a scan is the first thing in order or after the plug change?

Thanks again...

 

I agree with bluegrass, i suggest when you change the plugs look for hair line cracks on the tops of the cops as well as the boots and the springs inside also. not sure if you removed the tps when you cleaned the throttle body as the cleaner will damage the tps

 

TPS, nor any other emission sensors have not been removed...yet. I will begin with the basics here and go from there.

 

After hooking this truck to a better scanner at Autozone, they were able to pull a P1506 - IAC overspeed code. Prior to this I pulled the IAC valve off and cleaned with deep creep.

Well...an $11.62 Motorcraft PCV valve fixed the "vacuum leak" indicative of what the recent symptoms were indicating. Truck comes back to idle as normal now...pulled the battery cable overnight to let the computer clear and re-establish itself this morning.

After combing the vacuum lines externally for a failure, I got to thinking about where internally it could be leaking. I am not a parts changer to fix things but the PCV valve was long overdue as it did not get changed when I purchased this truck w/ 97k on it years ago. The old one was free but very dirty. After checking my records I had purchased one from Carquest when I purchased this truck years back but didn't install it. After perusing this site, I learned nothing but the Ford replacement was recommended. I am thinking this change will also help to retifying, if not resolve, the smoking/oil comsumption issue. This truck had not used any oil prior to being garage.

Thanks guys...I appreciate your help in getting my mind around this problem!

 

Good you arrived at a solution.
The over speed code is not unexpected.
The idle speed table has limits just like any of the other tables and will set a code if the idle is too slow or too fast.
The Crank sensor is the RPM tach telling the PCM what the motor is doing.
The PCM then adjusts the IAC opening on a continious basis to match the normal idle table range to within +/- about 50 rpm for hot idle.
On cold starts, the table is not used 'for that value' but has to account for fast idle and return as the engine temperature increases.
It's all pretty complex and absolute computer control.
Anything that upsets the data feedback will result in an issue and a code.
This is a point where the computer is never wrong in a fixed system design unless it's altered from outside or sensor and other hardware malfunction.
Good luck.