Engine/Transmission (1998.5 - 2002) Flat spot

[hcpBILL]

My '00 3500 4X2 truck has developed a "flat spot" when accelerating in 1st or 2nd gear (6-speed). When driving away from a stop I can put the pedal way down and it does not accelerate well at all, then it seems to catch and take off. This flat spot is at low RPM only. The truck only has 50,000 miles and otherwise runs very well. One suggestion I heard was that the intake air temperature sensor gets dirty because of the exhaust brake and causes this.

Any suggestions?

Thanks

Bill

 

[C.Solomon]

I would check fuel pressure if you havent done so already. Are you getting the CEL?

Could be a map sensor also.

Are you seeing normal boost #'s?

 

[Sticks]

Sounds like a fuel pressure issue, or the injection pump is on it's way out.



Check your fuel pressure at prime (KOEO) idle, and WOT for 5 seconds. If you do not have gauges in the truck, WOT fuel presure should not drop below 11 psi, under load it will fall lower. Regardless of Cummins and DC, fuel pressure below 10 psi is bad.



If your fuel pressures are OK, sitting in nuetral and snapping the throttle to WOT, the RPMs should climb evenly and smoothly all the way to governed RPM (3300 ish). If not, most likely the injection pump is on the way out.