I posted this in the engine section and now I am here.
Motor runs perfect. Idles beautiful in park performs great around town and on the freeway. I can shift into reverse and no problem. If I am parked and shift into drive the truck will die. No stutter, RPMs just drop and she dies. If I am driving and slow to a stop, there is a shudder and the RPMs drop but then come up to 600 or 700 and hold fairly steady, but won't die. If I come to a hard stop, she will die. I notice a mild shudder at low speeds with the foot on the break (like cruising through a drive thru), however I have brand new rotors all the way around. New suspension, etc...
I have replaced the IAC.
The EGR and it's related parts (DPFE, Regulator, etc...) are all new
The MAF is new
The TB was cleaned not too long ago
New COPs
The transmission was serviced (flush and new filter) about 25k ago.
Gas mileage is normal
Shifting is totally normal
No CEL
OD works perfect, no flashing light on the stick.
The truck has 160k on her now.
Any ideas?

 

Check for Vacuum leaks
The best way to check it is a bit of propane around vacuum lines

 

I don't think it is a leak as there is no code and has not been one for about 200 miles since the issue came up. I have checked all the lines and elbows including the notorious TB elbow of death. I have NEVER replaced the PCV and I am wondering if that could kill the truck. Any ideas?

 

Here is the scenario:
After the truck has come up to operating temperature, it will die when shifting from Park, Reverse, or Neutral into Drive.......The motor idles as smooth as glass no matter what temp in the park, reverse, and neutral drive ranges. If I come to really hard stop while driving, the motor could die and has. At a normal driving stop the idle may drop a little but will return to the 600/700 range with a little stumble here and there. The vehicle does NOT stumble when I accelerate. In the past year and annoying lag has developed between 2500 and 3000 rpm. This occurs when accelerating at the half and 3/4 throttle angles. There is a consistant pull, the lag and then the pulling resumes (clutches?)At WOT the 1-2 shift is a bit course and definitely takes longer the 2-3 or 3-4. Overdrive works perfectly on the highway and at all operating speeds. I believe I feel a slight shudder when rolling along at low speeds or coming to the stop. My rotors and pads are brand new and true (I have less than 10k on them) so I do not believe that shudder to be suspension (it's a year old), brake, or tire related. When slowing to turn corners the power steering pump will not whine but rather make a rubbing noise and there is intermittent vibration akin to something like a bearing rubbing that is felt in the steering wheel.

To date I have done the following:
NO CODES (CEL OFF)
NO BLINKIG OD LIGHT
Replaced all COPs one week prior to this issue. The truck sat for that week at the airport.
Replaced IAC (the old one still worked but what the hell, 161k, why not?)
Replaced the PCV
All vacuum lines and ports look good. No leaks.
Pulled and cleaned (again) the throttle body and intake
Dropped transmission pan, fluid looked pretty good. There looked to be some superfine particulate matter in the fluid but nothing out of the ordinary. I had the tranny flushed and serviced with a new filter about 35,000 miles ago.
I closed the pan and topped her off with fresh fluid.

I keep thinking it is the transmission........Can some one explain to me or brief me on the workings of the transmission? I am wondering if the accumulator spring may be bad or broken? Can I replace the clutches?

I am posting this into 2 forums BTW. Sorry guys. I will monitor this from the transmission forum unless someone here is familiar with this as an engine related problem.

 

I will post this in the motor section too.
I can't frkn believe this..........I picked up a factory induction system from a junkyard and installed it in the truck a year ago. I had an after market when I bought the truck and chucked the original. That being said, i never paid attention to the fact that there is a plenum that the MAF is attached to in the airbox. Mine from the junkyard was rigged with the MAF being held in place by a rubber coupling that was literally wedged into the end of the airbox......I went back to the yard and got the correct airbox this past weekend. No more lean codes, however I am still dealing with the motor stumbling when I shift to drive. It doesn't act up when the truck is cold, only when I get up to operating temperature. If anyone can explain, I need to understand what is taking place in the transmission when I shift into drive, i.e. clutch pack one is grabbing first gear, the torque converter is doing something, the accumulator springs (1-2) are doing something. If anyone can give me a general idea of what is happening, please share.

 

check the lines going from the intake to the drivers side valve cover and to the IAT one of the lines could have a kink or may have come undone.

 

They are connected. We is good there.
Thanks Tarajerame.

 

What about the tuner - did you get rid of that yet? set it back to stock?

 

Yup, returned her to stock tuning.
It's funny because now I can't tell a whole lot of difference between the stock tune and the canned 93 tune since I replaced the COPs.
I need to ebay the hypertechIII for sure.

 

Well, Idunno- sounds like a communication problem between the PCM and trans. Like TPS information -MAF information maybe - The trans relies on quite a few sensors so it's a tough problem. These trucks have to have some sort of neutral safety switch , but I never had a run in with one yet.

The trans has it's own harness, you might want to check that..

You can try to re-adjust the TRS sensor, maybe it's a little out of alignment.

Clutch pack ? That's in the rear end.

Has the OD switch blinked at all ? If so , that needs to read at the dealership. A simple auto zone scan tool won't pick up a trans fault code.

 

Thanks again for the info and the white papers. It looks like I can access the TRS from the drivers side with out dropping the tranny. I am not sure how I could "Adjust" it hough. Perhaps you could explain?
For the moment this is still just a stopping/parking issue. I'll be as descriptive as I can.
When the motor is cold, it does not display these symptoms. With in 15 minutes of driving the symptoms appear. The stumbling that occurs when slowing to a stop is interesting. Once the vehicle has come to a complete stop it is acting like it is late shifting into neutral or engaging the clutch....The motor will stumble down to about 350 rpm +/- and then very smoothly regain its 650/700rpm idle. The engine will NOT race or over rev by any means.
There is no hesitation when I step on the gas to accelerate fro a stop, the truck immediately goes.
When shifting from reverse to drive, there is a delay before the tranny actually engages. A few seconds I am sure. I do NOT here any "clanking" when shifting into gear so I haven't examined the U Joints.
When the motor is up to temp after driving and I pull to a stop and shift into park, then back to drive a few seconds later, it will die.
Turning the wheel and pressing hard on the brake pedal does not seem to have an effect either when I am shifting into gear, just to check if I have a bad power steering pump. I had an 85 V6 S-10 Blazer that had the pump go bad. The motor would die when I would turn the corner. Funny. Replaced the pump and no problems.
The OD light blinked when I turned over 100,000 miles. I had the transmission flushed and replaced the filter and new fluid. It was like $175. Never had the OD light again.
There is a slight shudder when I am rolling along up to 10 mph. I have new rotors and new pads. The suspension was recently replaced, tires are balanced and alignment is true. The shudder feels akin to a torque converter shudder...........

 

I don't know man, I wonder if that could be torque converter related ? Glad I never went through this problem - wish I could be more help. Have you ever noticed any wetness on the floor board? I'm thinking GEM fuse. That can do some strange things if it's getting wet. You'll have to look that one up in the forums because that's all I know about it.

As far as the TRS line up procedure -

Cable and Bracket Adjustment —4.2L, 4.6L with 4R70W Transmission

First verify that the vehicle will start in PARK or NEUTRAL and backup lamps illuminate in REVERSE. If not, then I'll get the procedure for you.

If I come across anything remotely similar to your problem , I'll post it..

I hope you find out what it is , good luck..

 

The truck starts fine in Park and Neutral and reverse lamps do come one.
I am going to talk to the wifes uncle and see if he will do the rebuild with me. He is a big ford guy, and a big gear head. The dude has a lift in ONE of his garages. I will tell you about the cars another time.
2008 Shelby GT500
1968 Shelby GT500 KR NUMBER 7!
1968 Shelby GT350
1964 1/2 Mustang 289 Factory Original and MINT condition.......

Like I said he has a few

 

WOW!! Those are some nice rides - he would be my favorite relative that's for sure.

Yea, I was trying to think of everything but a needed rebuild - figured that as a last resort. At one time I was looking for a new trans - Mine was slipping from the line tho. I tore apart the bottom end - cleaned up the valve body , installed a shift kit , added Amsoil and that saved it - it's still strong as hell w/233,000 miles on it. But I also have the HD trans - It's easier to work on than those 4R70W's IMO.

Yea , those cars sound killer - all of them.

Best of luck..

 

It sounds like a lock-up torque converter issue to me. Can you watch the tach to see if there is normal lock-up function?