Acceleration problem (hesitation)

[micklongley]

Hey all, I have a problem when getting up to speed when cold. I start good in 1st and it goes well and shifts into 2nd (hard shift). When going around 50mph I have it floored and it doesnt seem to accelerate any more. Then when I let off the throttle sometimes I lose speed and thats that, and sometimes it feels like a burst of power and it flies until it shifts at about 60mph or so. Could this be a problem with the Accelerator Pedal Position Sensor Module (APP) or maybe some other sensor. Could it be some kind of vacuum problem. This really sucks when trying to leave my driveway that is connected to a very busy highway. Ive also heard the transmission governor may be suspect. I really need help! Thanks guys

Mick

[nathan71]

The exact same thing happened to me this morning with my '87 6.2. I figured that I was in a hurry, and should of just let it warm up a little more (or some).

[More Power]

The mechanical DB2 fuel injection pump can act a little screwy when the HPCA is activated AND the fuel filter needs to be replaced or the fuel lift pump is not generating fuel pressure.

While the HPCA is activated (up to 95 degrees engine coolant temp), the housing fuel pressure is low, which advances the timing when cold.

So, you may need a new fuel filter and/or need to test the operation of the lift pump.

MP