cruiser54

IIRC, we turned the flywheels on 4.0s at least up through 1992 when I left. I have heard that you can't do it on the LATE 4.0s.

I don't know. Let's see a photo of a valve cover turned upside down.

EGR is a vacuum leak when it's sticking open. Probably should address that first and take it out of the equation.

They fit. So does almost everything else IN the cab.

Here's something you ought do while that valve cover is off. It was an unpublished factory fix for oil in the air cleaner on 87 to 90 4.0s.. 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.

I used to use these guys alot when I was Parts Manager at a Datsun dealer years ago. They had patterns for all sorts of stuff. Might check them out. http://autockms.com/

Absolutely check all your levels as Pete suggests. Eliminate the mechanism like he says too.

Cap and rotor with brass terminals. Clean your throttle body and check your intake manifold bolts for tightness.

Probably be fine. Good job!!

More than likely. That needs attention first and foremost.

The gauge would read Empty, unless the wire that fell off touched bare metal. Then it would read Full.

It's not the cause of your problem. If you've already cleaned it, you're okay. The wire from the sending unit to the gauge is probably grounded somewhere.

That tells me that the sending unit wire is probably grounded out somewhere. Always a good idea to refresh the ground behind the taillight as already suggested.

You mean goes all the way to full and past, then stays there?

NGKs and Napa/Belden wires will be fine. What about the cap and rotor? You don't need fancy wires and you don't need cheapie wires.

The ISA wore out inside. Little gears and such. I know of no service that can be done to one. But, vacuum leaks can drive the eCU crazy trying to keep the ISA in the right spot. Fix the intake leak and check the crappy hoses around the throttle body.

There's a special washer for under the bolt. Look at the other ones and you'll see what you need.

Carena, not an unusual fix. Thanks for your input.

Should not be on 100% or it will freeze up and blow hot air. 38-40 out the vents is as good as it gets. Run it.

Fix the vacuum leaks for sure. A little piece of vacuum hose as a splice will be fine for the small plastic line.

This^^. If it were mine, I would unplug and clean the 10 pin connector anyway, and remove the ground wires from the left inner fender and scrape the area clean and reinstall the wires tightly. It's only a sheet metal screw.

Nothing other than using good quality cap and rotor with brass terminals, Champion copper or NGK plugs, Belden ignition wires from Napa.

On the 2.5, there are a few vacuum lines around the throttle body that tend to rot. You can find vacuum leaks by spraying an oxygen sensor safe carb cleaner around the suspected areas. You'll know when you hit it. The idle will change dramatically. Don't rule out a bad TPS. Also, while you're at it remove the bolt holding the ground strap to the firewall. Scrape the paint off the firewall, clean up the connector and bolt it all back together.

Yep. Either take this advice, or get a used Honda Civic.

The wire to the gauge is grounded out somewhere.