Hey folks. Just to give a little backstory. I have a 1970 Jeep CJ-6 that I transplanted a 305 TPI motor from a 1992 Camero into. This is backed by a NV4500 5 speed. When doing this transplant I used a Painless Wiring conversion harness and had a new chip flashed for the computer by Howell. The new chip was just to eliminate some of the emissions equipment.

I have been driving the Jeep for about 5 years now but since it is a trail Jeep I only put about 1000 miles on it a year.

It has really seemed to me that my gas mileage and power in general has been lacking since the transplant. I actually have several friends that run versions of this motor in their Jeeps as well and they used a modified factory harness. They had a lot more trouble getting their projects running and making them reliable but they get better gas mileage and have more power than I have and do not run rich.

I know for sure that my Jeep is running rich. I can smell raw fuel often and it back fires on deceleration. Some times at high way speeds in overdrive it will actually start popping as well.

My check engine light does not come on and I really don't even know where to begin. I thought about trying to change my spark plug gap. I am running Split Fire spark plugs and wires that were set to the "factory" gap out of the box.

The engine starts and idles great. It smokes a little on start up but it is from the oil that leaks past the valves which apparently is common with this year.

Any suggestions? Thanks in advance for the help!

 

woh, there are a bunch of things it could be. 02 sensors, dirty or bad map, sticky injectors, high fuel pressure, tune gone bad. can u scan it? if so what if anything did u find?

 

I can scan it but the check engine light has never come on. I guess I will try to hook a scanner to it and see what I find.