porchlite

Hello,

I've been battling P0301, P0306, P0300 codes. I have done all the basics and more (new spark plugs, new oem sensors, new sensor connectors, new injectors, new coil rail). It runs better than it has in a long time until it doesn't. After much googling I think my symptoms match this service bulletin 09-003-03

http://wjjeeps.com/tsb/tsb_wj_0900303.pdf

So i ordered the valve spring compressor to perform the valve rotation called out in the bulletin. MD-998772A. No instructions on how to use the actual tool. Generally these things are pretty self explanatory but its completely possible I'm wrong about how its supposed to work.

From what I can tell when you take the valve cover and the rocker arms off the tool is supposed to thread the rocker arm bolt holes. The problem is the tool has metric threads. The holes are standard. The tool has two different size adapter studs and the other size would be about the right size for the valve cover bolt holes but the same metric on the tool, standard on the valve cover problem is here too.

In looking more into the tool there are other adapter studs for certain models that have different size threads on one side for what gets threaded to the car. I can't seem to find what is supposed to be used for my cherokee. The ones for other cars don't have thread sizes on them just part numbers so I can't tell if they would work without having them right here. The adapter stud I would like would have 5/16 - 18 threads on one side and M8 1.25 on the other. 1/4-20 with M6 1.00 would work too. Can't find anything online to make that work.

Has anyone done this procedure and tell me what I'm doing wrong or what special adapter bolt is needed?

Pictures of the tool are attached

Basslicks

I would return that one and get one like this:



Then, go and get an "air valve holder" tool like this:



One end threads into the spark plug hole on the head, the other end threads to an air compressor quick connect fitting for your air compressor.

Without the air valve holder, you can compress your valve springs all day long and your valves are just going to open down into the chamber and not give up the keepers. You have to have something underneath to hold the valves up to be able to do what you need to do.

CobraMarty

He doesn't need the air valve holder. He just needs to relieve the spring pressure and rotate the exhaust valve 90*.

Before I did all that, I would do a good chemical clean.
-Spray SeaFoam into the TB while running
-pour 1/2 can SeaFoam into engine oil and other 1/2 can to full gas tank and drive.
-pour 1 bottle Chevron Techron into next full gas tank and drive until empty.
-pour quart of water very slowly into TB while running at 2500rpm
-pour small bottle of Marvel Mystery Oil to full tank of gas
-change the oil and filter, use Rotella T6(high detergent) x 2 oil changes then Mobil 1 5-30.
-New spark plugs gapped to 0.035"

I have done this to all my over 150k 4.0 engines and has cured rough running, poor mileage, misfires, lifter tick, overheating.

I can't say enough about maintenance. I pulled a valve cover once and there was at least 1" of crud/sludge on everything. It was almost a mold of the inside of the valve cover.

cruiser54

A buddy of mine went through almost the same scenario. What finally worked was the old water trick.

Basslicks

I'd be interested in seeing how you do that. When I did the valve guide seals on mine, I could relieve the spring pressure all day long, but the valve drooped down with the springs when I would compress them. How would you rotate the valves in that scenario?

CobraMarty

Use that claw finger tool, compress spring slightly, rotate wrist turning tool, spring and valve all together.

Basslicks

Ah I gotcha. Yeah I guess that WOULD work fine if all you're doing is rotating them.

5-Speed

Marty - Why would you rotate the valve 90°? They spin on their own when the engine is running. Seems kind of pointless to me.

porchlite

That's the point of the service bulliten. Carbon build up won't let the valves spin. Closes slower and causes the misfire code. Manually spinning it before using the cleaner is what is reccommended.

5-Speed

Guess I should have read the first post a bit closer... I would still pass on rotating them and do the water method first. Its free and easy to do.