Eagle_SX4

My experience has been that is usually a vapor lock issue. Maybe try insulating the fuel line. DEI has some stuff that is great. I was able to get some at my local auto parts store. https://www.designengineering.com/heat-sheath-aluminized-sleeving-0-5-x-36/

It does not affect vacuum at all. The problem is that the oxygen sensor reads lean because of the extra air being sucked in to the exhaust and causes the computer to add more fuel. Making the engine run richer than needed, it has a hard time burning the extra fuel, causing the stumbling and poor running.

@boxyjeep sells ones. https://boxyjeep.com/products/jeep-cherokee-4-0l-egr-plate-1987-1990

That is the 91-99 manifold. I put one on my truck. It will fit but you will need to also change the down pipe and either delete the EGR or make a custom pipe for it. The good part is they are less likely to crack because of those flexible sections. You may also have to dent the front and rear tubes to clear the Renix intake manifold.

@NickInTimeFilms did a good job with this video.

The more I think about it, the more I am leaning towards cracked exhaust manifold. Pull the air box out and you should be able to see the exhaust manifold and watch it while it is running. Or if you have access to a smoke machine stick it up the tailpipe and check for leaks. A bee smoker can work as well if you have one.

Yeah if your exhaust leak is after the oxygen sensor, it won't make much difference in how the engine runs.

If you are looking to buy one DEXJ sell them. https://www.dexjs.com/products/jeep-4-0-2-5-oil-filter-adapters-all-styles

Installed ZJ tie rods. I had previously installed the 94+ XJ drag link. Now everything is the bigger 22mm threads.

Have you tried swapping the turn signal and hazard flashers yet?

If you have a Renix filter adapter it will have a long tube beyond the threads. Both the ones I have replaced looked like this. The after market H.O. ones I replaced them with don't have the extended tube on them

The most common issue with the blinkers is the front bulb sockets themselves. They get corroded and cause all sorts of strange issues. The only fix is to cut the old ones off and wire new ones in.

If you take the air box out you can get to all the bolts from the top side. It is a little bit of a guessing game on the center 2 on the bottom but you can get them.

Good luck on the hunt for a computer. At my local junkyards the computers are the first thing to be pulled.

I have used that website several times. It is a great tool to have available. Thanks.

Did it come with a computer?

If you are sure you are going to run the 4 liter, I would pull the harness and computer from a 91-95 XJ. The sensors are easier to find than the older Renix stuff (87-90). What year is the 4.0 you have? The engine date code is found on the side of the block as described in this post.

I agree, rotate the adapter. I have looked at some pics of the adapter and it can be clocked in that position or with the filter pointing up with out taking the locating pin out. Just change the o-rings when you pull it off and rotate it. What is the part number of the filter you are currently using?

If the harness you have is installed in the truck, my guess would be it is for the 2.5 that came out of the truck. Look for the fuel injector connectors. If it is a 4.0 harness it will have 6 connectors that look like this. The hardest part of this build will be finding a complete 4.0 harness and computer. (Easiest route is buying a XJ to harvest everything from).

The oil filter adapter can be rotated to any angle you want. There is a location roll pin pressed into the block that can be removed and you can turn it any way you want. If you want to change the oil filter to the newer 3/4 thread the part number for the threaded adapter is 53007563AB. The oring sizes are listed here by Cruiser54

No it is not me, it is @H3ADBANG4L1F3

What year is the truck? Does it have any engine wiring?

Is this what you are looking for?

I pulled some out a 98 XJ in the junkyard oem and still very flexible.

You may have gotten a H.O. fuel pump. The ohms for the Renix and H.O. sending units are backwards from one another. Meaning a full tank with a H.O. sending unit will read empty on a Renix gauge and vise versa. (they are not perfectly opposite ohms)