i picked up a 99 1500 z71.had it in four low going on flat dirt and it did fine.when i started to climb a hill the rpms drop 500 then jump back up.i was im the 1500-2500 range,nothing hard core either just flat slightly wet dirt road.it has a newly installed performance auto trans with a stage 2 shift kit,4in lift,auburn posi.i just bought the truck and when i test drove it everthing was great.its not my daily driver so its not like i'm out but i stilk want this thing to be able to make some trail runs at some time in the future.love the vortec V8 though!!!! punchy little bastard! thanks.

Are you getting a check engine light? Check tps connector/wiring too...

i picked up a 99 1500 z71.had it in four low going on flat dirt and it did fine.when i started to climb a hill the rpms drop 500 then jump back up.i was im the 1500-2500 range,nothing hard core either just flat slightly wet dirt road.it has a newly installed performance auto trans with a stage 2 shift kit,4in lift,auburn posi.i just bought the truck and when i test drove it everthing was great.its not my daily driver so its not like i'm out but i stilk want this thing to be able to make some trail runs at some time in the future.love the vortec V8 though!!!! punchy little bastard! thanks.So its a new to u truck. I would change the fuel filter at least unless you know it is good. Could be plugged.

it has a service engine light on.it does put out some codes when you scan it.it says theres a air pump malfunction,could be clogged.the guy i bought it off told me about this and i called my mechanic and he said it was an easy fix. twards the rear of the inner front fender right next to the ai cleaner therd a pump i guess.it goes into the shop on monday so i guess we'll see.i will pass tje info on to him.these V8's are alittle out of my leauge, toyotas i can work on but all she smog and computer stuff is kinda out there for me.thanks for your advice

it has a service engine light on.it does put out some codes when you scan it.it says theres a air pump malfunction,could be clogged.the guy i bought it off told me about this and i called my mechanic and he said it was an easy fix. twards the rear of the inner front fender right next to the ai cleaner therd a pump i guess.it goes into the shop on monday so i guess we'll see.i will pass tje info on to him.these V8's are alittle out of my leauge, toyotas i can work on but all she smog and computer stuff is kinda out there for me.thanks for your advice

Post the codes it throws!!!! Might save you some money form the "shop". They are actually pretty easy to work on!

it says port air circuit malfunction.air system bank 2 fault.no change in O2 sensor voltage during air system test.possible causes,air pump elec circuit fault,blocked air system,failed air pump. all that stuff was an a print out i got from the guy i got this thing from.any ideas? thanks.

it says port air circuit malfunction.air system bank 2 fault.no change in O2 sensor voltage during air system test.possible causes,air pump elec circuit fault,blocked air system,failed air pump. all that stuff was an a print out i got from the guy i got this thing from.any ideas? thanks.
It would have been better to post the actual numbers of the faults, shoudl be on the print out.

What motor do you have?