cruiser54

No real need for the ECU to learn what the IAC is doing on a Renix.

Got a multimeter and know how to use it?

Do you have the trans switch in the Comfort mode?

Good idea. They were meant to last for 67,000 miles.

No new igniton wires? Ever refreshed all your grounds or checked your sensor ground circuit with a meter?

Plunger sticking out is closed positon. Do you have tune up issues? IAC will not cause a miss.

REmove and clean the battery connections. Do the same with the other end of the cables. Wiggle the ends and listen to hear any crunching sounds indicationg corrosion down inside the insulation.

No reading out of the 4 prong connector is the smoking gun here. That's the side for the trans. Can't find power at that connector at all? There's the issue. Try this: Cruiser’s Trans Plug Refreshing Over near the trans dipstick tube are 2 rather large connectors. One is black and the other gray. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and trans solenoids. Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in. Revised 3-28-2012

I'd be looking up above first, and VERIFYING the source of the oil leak yourself. Many mechanics, friends, and good old Uncle Bob love to tell you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon just yet. Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons. First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill". Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first. Revised 8-15-2012

yes, that could be the use but also if your piston rings are gone it also causes pressures to go up and will start making gaskets fail. correct me if I am wrong guys... More than likely NOT rings.

I have a photo but can't post it up. Help!!!!

The valve cover. And grommet gets puckered.

It is a disease: Orifice Puckeritis.

Works great.

Yes, they will bolt up 258 to AX-15.

Maintain your CCV system as mentioned, and do this: Cruiser’s Valve Cover Mod Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin. Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.

Have you tried Crown, TeamCherokee or any of those suppliers?

I've removed the rod from my rear prop valve and ziptied the arm in the straight up position. That gives the most braking to the rear. I have no lockup problems. You have a leaky axle seal? You sure both tires are locking up?

Well, you better learn how or you'll have fits getting the replacemant started. It's super easy. With #1 spark plug removed, turn the engine over clockwise using the 3/4" front crankshaft bolt. You will see the degree marks on your front cover. You will see the timing mark on the balancer. Mark them with chalk or white-out. While turning the engine over, put your finger/thumb over #1 spark plug hole. As the mark on the balancer approaches the marks on the front cover, if you are coming up on #1 TDC, pressure in the cylinder will push on your finger. If there's no pressure, you're at #6 TDC and need to crank the engine over til you see the marks coming together and you get pressure. Set the mark on the balancer to the 0 mark on the front cover.

Yes. Both engines at #1 TDC. Know how to be sure of that?

Correct. Now ... if the problem is pinging, and it's a Renix vehicle, the problem could be a broken knock sensor. Absolutley.

Hard to beat a system that gives alot of advance and has a knock sensor to keep the engine from piniging for ya.

Yep. Even on a Renix.

Why do you think you need to adjust the timing?

My thoughts exactly. You guess which ones!! Hey, you stuck with it and got it done. Perhaps you can help someone in the future with your newly acquired knowledge.