Try starting in 2nd gear and see if it starts exactly the same as in drive. It may be the modulator on the trans. It controls the downshift to 1st gear. I have found mine needing adjusting from time to time. Some are adjustable and some need replacing. Anyone on the board familiar with trannys could tell you. Just my 2 cents.

 

I agree, it sounds torque converter related, or possibly never gets into first. As was just suggested, try starting out in 2nd, see if the behavior is the same.

 

JMC:

I just found this post in some of my older posts. To clear this issue up, sometimes when you have the machine in gear, and you're at a standstill, you won't move if you let off the brake. Sometimes it will. It almost seems like that if it's warmed up, the chances are that it won't move when you let off the brake. If it is cold, more than likely it'll move right away. Sorry to be diggin' up such old posts. Thanks

 

Blue_Farmer,

From a stand still start off with your foot to the floor. Have a friend with you to see what speed in MPH that it upshifts to the next gear. Try it in your friends truck and compaire the MPH

JMC

 

Sounds like it could be a clogged fuel filter.

 

it's not the fuel filter, i just replaced that about 10k miles ago, and it didn't help when i did that. Thanks

 

Blue-Farmer- I am a little late getting into this but it sounds like to me you have a transmission problem. First gear is definately giving you trouble from your description. It really sounds like a slipage problem to me. Try a fiuid and filter change with the addition of transmedic or such for slippage. This may help. If not it may be time for rebuild. Have you tried reposting this thread to "Factory Tech" 's attention and under the transmission FORUM. I hear he is a tranny GOD.

 

You might try checking the TPS voltage at closed throttle.
This link shows how to do it but it's on a lightning.
https://www.f150online.com/forums/sh...rottle+voltage

 

how about the modulator idea? how do i go about adjusting it? I can't imagine that the fluid that I put in there like 10k miles ago is bad, besides, it was the exact same before and after the new fluid and filter. I think I used a decent atf, i used pennzoil synthetic blend mercon V. Done a complete fluid change, including the TC drain. Thanks guys. Oh yeah, I've got an extended warranty that covers basically everything. So I'd like to get this cleared up before that expires. Thanks again

 

Blue_Farmer, I think I know what you're trying to explain. Back in 97 My friend and I bought our trucks new at about the same time.

I got the 4.6 and he had the 4.2, the first time I drove his truck it seemed to have more instantaneous throttle response than my 4.6. I just tapped the gas pedal and it was rolling like right now whereas mine seemed to spool up a little more while it started rolling. I always though it was because we had different combinations of torque converter stall speeds and rear end ratios?

I know you have similar trucks but do you know if you both have the same rear gear? Is it possible that maybe your TQ has a higher stall speed? Maybe the different computer programs?

I'm sorry that I cant give you an answer but I do know what you're describing and it's a very noticeable difference.

BTW, I did a gear swap on my truck & another member had an identical truck with the same gear and both responded and drove differently despite being same year, engine/trans combo etc. So it seems that even trucks that are nearly the same still drive differently.

Good luck.

 

Blue,
You got a K&N filter. Maybe try cleaning your MAF sensor and resetting your computer. If it's dirty the truck will run like a dog off the line.