'01 2500 2wd auto 5.9

Truck has had this problem for a bit but it is getting worse, so...symptoms:

On start-up...put truck in drive and take off. You will get about 100' and then it just stalls...doesn't want to shift...feels like it has a governor. After a few seconds it will shift and then drive normally for the rest of the day. UNTIL you shut it off...then, on start-up, when you take off it will do it again. Every time. This only happens after you have shut the truck off...next time you start off.

The last few days it has gotten more reluctant to get through that "wall" and shift. May have to drive a mile on and off the accelerator pedal to get it to shift and go on. The only exception to this has been the other day when I was hooked to a load...it started up and drove off without incident.

What the heck is the matter with this thing? For what it's worth, a couple of weeks ago I replaced both batteries and cleaned all grounds down to bare metal.

Truck has a little over 300,000 miles, has hardly ever towed anything really... no mods, original injector pump...

Reading the codes off the oddometer I have:
P PCU
P 0720- Low output speed sensor-rpm above 15 mph
P 1693- ??.....could not find this one

 

1693 is simply a companion code - it means there are other codes present, which you got.

Original tranny? What does the fluid look/smell like?

 

Yes, original transmission. Fluid looks and smells fine.

It should...there is a pretty good leak & I regularly add fluid

 

Don't know where it's leaking or how much and might be a far fetched thought but here's my idea:

Problem is probably tranny related. The leaking between starts is decreasing pressure somewhere - upon initial start-up and circulation of tranny fluid - the transmission has to "re-up" the pressure where it has been lost - the time to re-up the pressure is how long before the truck drives correctly.

If this is right - your initial symptoms said the problem has gotten worse lately. Has your leak increased lately?

 

Thank you for your comments...and you may be right. Seems to me though that it almost has to be an electrical issue. It doesn't matter how long the truck is shut off...a few seconds or a day. It will always have that "stall" next time you start it and take off.

I think I am going to try and get it to a tranny guy today.

 

If your tranny has never had the solenoids replaced they are a likely culprit. Not super expensive but the pan has to be dropped. Your tranny guy can figure it out.

 

Your 0720 transmission output Speedo sensor fault. Means the tranny output and input rpm parameters don't agree. Pull out the connector and have a look for bad or burned terminals, or weak pins/slides. If that's not an issue, pull the sensor and clean it. It will be on the lower left of the od housing.

See if this works, report back.

Carry on