Engine/Transmission (1998.5 - 2002) Intermittent power loss problem

[rbagley]

I'm writing this for my uncle who is in Northwestern Florida. He has a '99 3500 Ram with 24V CTD w/automatic transmission.



He has been experiencing intermittent power loss lately. The truck will fade out and then come back in. He thought it was the fuel filter, changed that, same problem. He took it to a local dealer, they said lift/transfer pump. It is still under warranty so he let them do it.



We got back from a West Texas Mule deer hunt and he got home last friday. He says he still has the problem, but only when the truck is cold now.



You folks are awesome at diagnosis so I thought I would give TDR a shot at helping out.



Any help would be appreciated,



Thanks,



Roy

 

[Sticks]

Check for codes. The MIL light does not have to be on to have them. If his LP was bad, the VP44 may have taken some damage and is on its way out. Could also be the APPS/TPS.

 

[rbagley]

Thanks. I'll pass that on. To check for codes, you turn the ignition switch through the full cycle three times, leaving it in the "on" position the third time?

 

[Sticks]

I don't think that works on the '99s. I read something somewhere about maybe holding in the trip meter reset when you turn it on to get codes on older models (with digital odometers) but I can not confirm that. Try the key thing, otherwise go to Auto Zone and have them check the codes.

 

[rbagley]

Update



I spoke with my Uncle this morning and it is not just a "cold" only thing now. He said he barely made it over a bridge going to the dealer yesterday afternoon.



APPS stands for what? I'm pretty sure TPS is throttle position sensor, but I can't figure out APPS.



Thanks.

 

[DavidC]

APPS=Accelerator Pedal Position Sensor

 

[rbagley]

The dealer has now stated that the MAP sensor is bad. I haven't heard if they replaced it yet.



Could the MAP sensor cause lack of power?

 

[rbagley]

Last update:



Dealer installed MAP sensor and so far this has corrected the power loss problem.



The dealer did say that he needed the lift pump anyway as it was putting out low pressure. Less than 15 PSI