NC Tom

Great info. Thanks!

Minuit, would a damaged pin really cause the voltage to read incorrectly? The probe is pushed down in. Doesn't seem like it would be an issue.

Okay. When you say "everywhere" where is that? I've never looked for these parts before.

Yeah, I guess NAPA's Proformer at $47 is my best bet.

I don't know if it's a secret. I just can't find anything listed as "OEM".

I can't find OEM. Where did you see them?

Okay. Just being thorough here. Per @cruiser54 's Renix tips, I plugged in my meter, set to ACV, turned engine over and got .259. That means replace CPS correct?

Okay, safe to assume it could be causing no-spark symptoms? Thank you.

Starting to trouble-shoot my no-start issues and upon unplugging the CPS, I found this. Looks off to me. However, it's a Renix, so I don't know what the French were thinking.

Yes, I have checked them. Haven't used them yet.

I ordered a simple digital meter today from Napa. I guess I'll get out Sat and start taking readings.

Jeeess! All I wanted to do was to change my fuel injectors and it's turned into a project of biblical proportions. The truck ran well before I started this thing. It would occasionally stall at a stoplight, but would start back up. I noticed an injector leaking, decided to change it and Blamo! Dead. I can't wrap my brain around why all these electronic things are popping up. I touched nothing but stuff around the rail. I'll start checking the things that you suggested. If I can figure out how to use my old analog multimeter.

Yes, I have the valve. I've never had a big spray of fuel, but now, it just leaks out when pressed. I thought the fuel pump built pressure and that's why I changed it. I've tried starting fluid in the TB without success.

Nope. Definitely no not have that. So, I have installed the new tank, pump, sending unit, lines, etc. and still no start. I am certainly lost on this one. I guess I should order a new fuel pressure regulator.

I'm going to try and work this pump in the tank. However, there is no hole in any corner of the basin.

Yeah, I realized that after I sent the question. Senior moment, I guess. Would you happen to know where I can find detailed instructions on placing this dang fuel sending unit into the tank? I can't figure out the proper orientation of the filter and the float. I've watched a few videos, but that info is not covered.

Thanks for the epic reply! While I wasn't asking for help, you did provide some good info. I too, am reusing the rollover valves. I did get the Cherokee filler hoses, a new tank, and an MTS pump. Why fuel injection hose?

Good morning all, Just a tale, not asking for advice. My MJ has been on jack stands for several weeks now undergoing many tests and parts changes. My latest adventure was dropping the gas tank to check/replace the fuel pump. Like many of you, I have watched several videos on the processes of removing/installing the parts I need. What I have decided is that the people who make these these videos rarely, if ever, show you what really happens when you start wrenching on these trucks for the first time. For example, the guys who have the vids on dropping a gas tank must drop their tanks several times a year just for fun. If you watch these vids, keep that in-mind so when your journey is not so smooth, you don't loose your $#!&e like I do! Now, to be fair, what they show is mostly helpful. However, they never seem to encounter the obstacles that I do. Pics attached for your viewing pleasure. Strap nuts that broke off. Vacuum hoses crushed and pinched under the straps. J-bolts seized and while trying to UN-seize it, it popped out and the tank fell right on my stomach! OOF!! Glad I had emptied it. Odd vent hose clamps so rusted I had to cut the lines to get the tank out. None of the vids I watched had clamps on the vent hoses? Worm Clamps so rusted and seized, I had to cut the hose. This was my point-of-no-return moment. Having done all this I have found small holes in my tank. So, along with all the parts and pieces I needed to put the tank back, I am now replacing the whole tank! Sincerely, NC Tom

For anyone who may be interested, the MTS part number for a fuel pump and sending unit is: JPSU-6P4.0 (COMANCHE MJ 1987-1990) MTS charges $166 plus shipping. I found the same part at justgastanks.com for $143.57 plus shipping.

Thank you, sir. However, my gut, and the reviews suggest that it's a piece of . . . well, it may not be good quality.

Okay, this situation may be more difficult than I first thought. I can't find a fuel pump assembly for an 88 MJ Renix. I have contacted MTS, but haven't heard back yet. Anyone know where to get one that doesn't require modification to fit? I really want to go the plug-and-play route.

I'm just gonna whole-enchilada and drop the tank and replace everything! Fuel pump, hoses, rusted clamps and bolts, gas tank bearings and fuses, refrigerator magnets, fuel pump linkage, grease mounts, fuel filter backwash and encabulator valves! If she doesn't run then, don't know what I'll do.

The filter is new. Do you mean disconnecting the filter > key on > look for gas squirting out at disconnected line?

Pete and anyone else who may be able to assist. Because I was curious, I cleaned and refurbished my stock injectors, reinstalled them and nothing happened. Still no start. However, there was fuel in the rail even though there was basically no pressure. I also tried spraying starter fluid into the TB while the wife cranked, but no start. Just turns over. Before I start throwing more parts at this thing, I figured I would post my latest attempts and see if anyone has any other ideas. If I have fuel in rail, but no pressure, is that the pressure regulator or the pump?

So, I do have fuel coming out of the rail pressure valve, but it's not under pressure. Just trickles out. Earlier today I got a turn, turn, turn, clunk, turn, turn, turn, clunk, turn, turn, turn, clunk. Mean anything to you? I had to stop because I have run the battery down. Hooked up a charger.