Engine/Transmission (1998.5 - 2002) truck shuts off, need help

[tragicwagon]

Recently i've noticed that my truck stops pulling at 85 mph like i'm letting off the accelerator and starts pulling again when it drops below 85. it seems to be speed related because it doesn't happen at any certain rpm and the pyro is not reaching the 1300 deg. mark, indicating that the banks otto mind is not defueling. the fuel pressure is not dropping below 8 lbs and there are no codes set. i've double checked all the connections to the otto mind and they are fine... . Does Anyone have an idea of what might be going on here?

 

[csevers]

Could the pyro sender be off? Making it defuel early?



Craig

 

[ntillm01]

Is this a new thing, or is it a built-in speed cut-off built into the ECM/PCM? Most modern vehicles have a speed cutoff built into the software (based on the speed rating of the tires) from the factory. I believe truck tires are rated at 85 mph, so that may be it. Yet I read about folks taking their CTD past 100mph, so I could be way off base. Anyone know?

 

[tragicwagon]

I dont think its the pyro because it will hit 1200 deg without defueling in 4th gear, and when it shuts off at 85 mph the pyro can be between 800 to 1200 deg depending on conditions, ( uphill, downhill,etc). as far as speed limiter the truck has been to 115 mph multiple times without problem. From what Ive heard the DSS only controls the ABS, so it dosent make sence for the problem to be speed related but it sure acts like it. Im sure someone on here has had this problem before and has the anwser,so come on guys I need speed.

 

[Sticks]

Give it a coupe of days

 

[tragicwagon]

TTT