motormayhem
Member
- 627
- 18
- 18
- Location
- Tucson, AZ
Just got the tranny rebuilt and some stuff done to the truck (new axles with 4.10 gears) and recently it seems like it is low on power. If I remember correctly when I would punch it from a stoplight before it would take off and you could feel yourself pushed back in the seat a little. Now when you floor it it bogs till about 20-25 and then takes off and bogs a little in the bottom of 2nd and 3rd as well. Also seems to run a little rough at idle and has a little black smoke at idle when it is under load (smokes when stopped in drive but not when in neutral or park). When I hit that gas it gives a decent haze of black smoke out of the pipes. I just changed the fuel filter with no change as well as removed the air filter which didn't help either. The IP is 1 year old with about 5,000 miles on it as well as the lift pump. It seems like the engine runs better when cooler 180 and worse around 190 (which is the hottest I can get it to and what it stays at in stop and go traffic). It starts fine. I also followed the test in the TM to test the lift pump which generated 9psi after 15sec of cranking (tm said 5-6.5) and 1 pint for 15 sec on cranking (tm said 1/2 min). What could be the problem? This is kind frustrating after all the stuff I have done to it recently. 
