99 TJ Bucking at 2000 rpm

[Gsmith]

Hello

I have traded for a 99 tj with a 2.5 which was recently rebuilt. The problem is it starts bucking when under load around 2000 rpm. Researched this problem all over the web but there is no certain fix. I do have a snapon code and data reader but everything reads within range, and no codes.

These are sensors i have changed so far

Upper o2 sensor
Tps
Cps
New distributor, and pickup plate
New cap rotor plugs and wires

Still bucks and jerks.
I do know the checkvalve in the regulator leaks down from putting pressure tester on, but does hold 50 lbs ideling and revved up. Also have done a compression check and everything is within spec.

I am so frustrated and dont wont to spend more and more money changing parts without some sort of direction.

PLEASE HELP

 

[wwch99tj]

It took me 3 TPS sensors before I got one that worked without bucking...
And I've replaced everything on your list as well.

Sent from my Samsung Galaxy S3 using Jeepz

 

[Gsmith]

It took me 3 TPS sensors before I got one that worked without bucking...
And I've replaced everything on your list as well.

Sent from my Samsung Galaxy S3 using Jeepz

Did you buy them at the dealer or local auto parts stores like autozone ?

 

[69jeepcj]

Sounds like the timing is off under load. If this was a carbed engine I would be checking the advance mechanism in the distributor, but I don't know how the timing is controlled on a computer controlled engine. you said it was rebuilt so they had to set the timing, maybe its wrong.

 

[wwch99tj]

Did you buy them at the dealer or local auto parts stores like autozone ?

Autozone, if the last one didn't work I was going to the dealer, so far so good

Sent from my Samsung Galaxy S3 using Jeepz