Engine/Transmission (1998.5 - 2002) Lag in acceleration

[rabsyeeha]

I have read the numerous posts on sluggish accelertion and related solutions by cleaning the fuel intake, addresing the lift pump, ECM etc... The interesting issue is, I am experiencing this only at 50mph. As the automatic transmission shifts over 50, the issue seems to resolve itself. Prior to 50 it's not really there (or not noticeable).

It seems that as the truck accelerates, getting to that speed there is a slight momentary lag, and the engine sounds almost like it's not getting enough air or fuel, and then kicks it up and goes on fine. If I continue at 50, the issue persists, but goes away with more speed/acceleration. The VP is pretty new, and lift pump a little over a year old. The fuel pressure is in the normal range. Just changed oil and fuel filters. Cleaned the air filter, and checked that no leaks are in any of the hoses. The connection at the pup also seems secure. Is the problem in the transmission? I recall reading that a governor there may be an issue. I had it serviced 2 years ago.



Thank you for the advise.

 

[DCreed]

Are you just feeling TC lock-up?

 

[JLandry]

Hi rabsyeeha,



How about filling in your signature so we can tell what year truck, what options, and accessories you have?



Have you checked to see if there are any stored DTC's (Diagnostic Trouble Codes)?



Have you tried replacing the MAP (Manifold Air Pressure) sensor?



Does the transmission feel like it's shifting at the proper points?



Regards,



John L.

 

[rabsyeeha]

I'll update signature asap. THe truck is a 2001 mostly stock, 234k on it. AFE filter and Edge EZ, with a straight 4" exhaust. I am not sure id it is a TC lock-up, seems to be shifting fine and at the right time. I don't know if I actually felt a TC lock-up before to say that I know what it is. I do need to read the codes, and will try replacing the MAP sensor. Thank you.