Two-fold question - I am by no means a pro on these trucks.But one thing I have noticed with mine.The TQ will not lock until the engine reaches a certain ...

I am by no means a pro on these trucks.But one thing I have noticed with mine.The TQ will not lock until the engine reaches a certain temp.I have noticed this since cold weather started.When I go to the next town,from a cold start,I go about 5-6 miles before the convertor locks.Never did it before.Of course,if you get all the way off the throttle,it unlocks.Once it is warmed up the first time of the day,it seems to be fine the rest of the day.My trans temp really does not come up much,till many miles down the road,then only to 160-175 or so.With my 18 ft enclosed trailer,the other day we ran 250 miles with 4 snowmobiles in it,and the trans temp hit 200.
During the summer,the trans temp has been 250 a couple times.And it comes up quicker.
I guess my point is,could this be a temp sensing issue,that keeps your TQ from locking?Or a bad throttle position sensor,or something related?
Good Luck Bob

I've thought of that, especially since I'm running AMSOIL in the transmission (which I've noticed keeps the temps lower). But it will lock up at slower speeds, just not higher ones. It may be a TPS issue, but I don't want to start throwing $$$ at it until I know exactly what's wrong with it.

Does anyone know if you can replace the TPS without replacing the whole throttle body? I called O'Reilly, and they said no.

I did some digging today, and here's what I found: I had the plow installed on Nov. 11. I only did city driving after that, until Nov. 15., when I went on a long trip with the truck. That's the first time it started acting weird. I hope the two events aren't connected... having to deal with that plow shop again is something I never want to do.

That is another reason I will never put a plow on my daily driver. A buddy of mine does plowing on a large scale and they have plows on a few trucks and they get about 3 to 4 years before having major issues ranging from front suspension to Trans and Diffs. It dont matter what brand they use, its just hard on them. They have had the best luck with the Ford Super Duty's because of the straight axle but they still end up having to get replacements.

I use to use an old bronco with a blade on it at a place I worked, The weight of the plow had the front end sagging so bad it would ride on the bump stops. Got the job done but thats the only thing that old bronco was used for.

starspangled6.0 wrote:I've thought of that, especially since I'm running AMSOIL in the transmission (which I've noticed keeps the temps lower). But it will lock up at slower speeds, just not higher ones. It may be a TPS issue, but I don't want to start throwing $$$ at it until I know exactly what's wrong with it.

Does anyone know if you can replace the TPS without replacing the whole throttle body? I called O'Reilly, and they said no.

not sure if you have the same/similar throttle body as me but on mine its easy, t15? (or t25) torx bit taped to a 1/4inch wrench or socket and ratchet will do the trick.

Do you have a link to a store that sells one? I looked at O'Reilly and Rock Auto, and they don't sell it.

Jon, 2003 must of been a year that they changed the throttle body. I can find the TPS for all years up to 2002 but nothing for 2003.

I had to replace one on my 99 S10 ZR2 years back and it was a fairly straight forward quick and easy job. The symptoms you have stated were not the ones that I had, I had issues with a high idle and it not getting enough gas. Also it threw a code so we knew exactly what it was from the start.

Just got off the phone with the trans shop. They said there is a misfire on #6, and whenever it detects the misfire, it unlocks the TQ. Unfortunately, they still haven't found what's causing the misfire. The saga continues... At least my tranny isn't what's causing the issue!

Bad news: They tested the coils, plugs, wires, and injectors on #6 and #1, and didn't find anything. They can't feel the misfire, but supposedly it's really bad at 2800 RPM, so they're guessing there's an internal problem . I'm going to start a new thread vortec-6-0l-v8/misfire-on-6-and-1-t9861.html, since it's definitely an engine issue now.

red16 wrote:I am by no means a pro on these trucks.But one thing I have noticed with mine.The TQ will not lock until the engine reaches a certain temp.I have noticed this since cold weather started.When I go to the next town,from a cold start,I go about 5-6 miles before the convertor locks.Never did it before.Of course,if you get all the way off the throttle,it unlocks.Once it is warmed up the first time of the day,it seems to be fine the rest of the day.

i was about to start another post in regard to this same subject, but is it normal then for these to not lock for a few miles down the road on a cold day? that is the same issue mine is having, but other than that, it seems to work as advertised, shifts fine and everything. and this symptom wouldn't have anything to do with affecting mileage, would it? because mine has gotten considerably worse recently, even tho a tune-up was done not so long ago and it was doing great then. only other issue i have with my trans is the ol' front seal leak, but it has almost 135k on it. i'm just trying to figure out if i need to have all this fixed really soon, or take it to the shop and diagnosed for the crappy mileage... only other note i can add is that around 70mph, running just under 2000rpm, sometimes, not always, it seems to run rough, so wonder if it may be related in some manner? a lot of questions, i know...

-keith