I have the 4.0HO i6 and it think it needs a timing... how should i go about this? Ive done timing before but want to do it right.
I heard/read something that i shouldnt start twisting the distrib cause of the PCM and what not. So kinda scared about that. What should i do to time my engine? I was going to loosen the distrib and twist it a little with a timing let set up to watch the mark... and set it 2* ahead.

 

You can't set engine timing on any of the 4.0 or 2.5 Jeep engines. Its all done electronically by the ECU

You can set the static time if you have removed the dizzy and forgot to set #1 piston on TDC compression stroke and forgot to mark the rotor location on the dizzy housing before removal

On the RENIX models you can get a high altitude CPS that will advance timing by a few degrees.

Also, you can't twist the 4.0 dizzy, it has a mounting tab on it and it wouldn't make any difference any way, the ECU will re compensate for the relocation.

 

Well hell it sounds like i have a miss fire.. running really ruff! What should i do ?

 

plugs, wires, cap, rotor. If it's still doing it check your cam position sensor and crank position sensor, as well as your injectors.

 

Check your plugs, wires, rotor button and distributor cab.

 

What do i exactly do to check these sensors and where are they?

 

lol, the cam position sensor is that plastic plate thing under need the rotor in the distributor, and the crank position sensor is mounted in the back of the engine near the bell housing. I'd honestly start with the tune up and maybe a good throttle body cleaning. Plugs, wires, cap and rotor.

 

I dont know how to check maybe ohm meter but cam sensor under the rotor and crank is mounted on bell housing

 

Do a quick compression check too. If it was overheated a blown head gasket could cause it to run on 4 cylinders. It can blow just between two cylinders and not to a coolant port so you would not have any other evidence of a blown head gasket other than two cylinders not firing.

 

Moved to OEM tech.

 

The headgasket was changed less the 5k miles ago. And had the head inspected