tetrad

I filled it up with about 2 gallons of gas I had sitting in a tank, and no leaks. Idled it for a few minutes, and no leak. Took it into the smog station and it failed the pressure test and then started leaking again :( I went to a salvage yard where they just got in an 88 MJ, and pulled the sending unit. It looks in much better shape. Not sure which pump I'm going to use. I'll probably be back in the next couple days to pick over it more (it was nearly closing time). It had a 3-piece slider that I'd love to get my hands on :)

Well I used JB weld, so here's hoping :) I wasn't able to verify exactly what was leaking, so I did all three fixes (new main o-ring, new wire o-ring and pushnut, slather with JB weld). I got everything put back together and reinstalled. The assembly is missing one of the tangs on the mating surface (rusted off) so it's not sitting entirely straight. I think the lock ring is pressing it into the o-ring tight enough that it won't leak, but it's probably only a matter of time before road vibes wiggle it loose again.

I pulled the sender and pump assembly. I'm gonna clean it up and go pick up my new o-rings, lock ring, and push nuts. When I put the new o-rings in, do I lube them up with petroleum jelly or just set them in dry?

Awesome, thanks guys. Sounds like a new push-nut + o-ring on the plug and/or epoxy on those hard lines will fix the problem. I now feel confident enough to tear into it and see what the damage is :) 88whitemanche, the link you put at the bottom of the other thread (http://comancheclub.com/topic/38976-gas-tank-leak/?do=findComment&comment=393159) was very helpful as well. I just had CA smog fail due to the gas tank not holding pressure (they pinch the two lines at the charcoal canister and then pressurize it through the filler tube). I think this leak is the source of the problem, but I want to cover my bases to minimize retests. I'm considering also dropping the tank to make sure the ventilation line(s) on top are in good shape, but I'm worried about being able to reuse the straps and nuts.

Does that help at all? I initially thought that it was leaking out of the circle about 1.5" out from the center of the pump, but maybe it was just pooling there to drip. Are you suggesting it could be those metal lines coming out of the pump face that are leaking? If so, a new pump and the same tank ought to fix the problem, right?

I've been wondering what to tie that to. Thank you! :)

Ah, I got thrown by your username :) Ouch!

No I don't have a lot of experience welding aluminum. The tank is the one from mac's radiator that people talk about around here. It's a very nicely made piece even if it's a bit on the expensive side. Cool, thanks! Good luck with the build. What are your plans for the bed?

I suggest posting a thread over on the MJ Tech forum for the no-start. Here is a link to Cruiser's Renix tips if you don't have them handy: http://comancheclub.com/topic/36382-cruisers-renix-tips/ It sounds like you've already cleaned up your grounds and coil contacts. If you haven't touched your C101 bulkhead connector, you might want to give Tip #2 a shot. Shouldn't take too long, and a lot of important signals route through it. Did you get a voltage reading with the new CPS?

Awesome, thanks for the info and advice :)

I'm curious what you wired the killswitch up to. I'm guessing as "killswitch" implies, this is an emergency engine shutoff, right? I just read through the entire build thread. This is a great looking truck! :)

That coolant tank looks slick. Did you fab it yourself?

88 4.0L short bed. My gas tank apparently has a decent leak when it's filled over a certain point (had it out on the road for the first time today since I got it, so it's the first fillup). It looks like it's coming out of the pump assembly mating surface, but the pump face and a big swath underneath it are pretty well rusted. I'm guessing it's not something that pulling the pump and throwing in a new gasket would fix. Does anyone have recommendations for a replacement tank (new, salvage, etc)? What else is it a good idea to replace while I'm doing it? Will the tank out of a 2.5L fit and work, or do they have any differences in the pump, sender, etc?

SHE LIVES! :thumbsup: I did the C101 delete (and sensor ground fix), still nothing. So I pulled apart the C100 and cleaned it out, still nothing. I pulled my ignition switch off the column and tested it - I was getting +12V at the starter line in start. I pulled off the starter relay coil wires and the terminals were very corroded. Cleaned em up and she started right up :) My dipstick ground is pretty messed up at the moment, which probably took out just enough current to not engage the starter relay with the corrosion. I've got a new full set of cables coming from Jon Kelley (http://www.kelleyswip.com/electric.html), so that shouldn't be an issue for much longer either. Cruiser, thanks to your mantra "RCBRC" I got the jeep running for the cost of some heat-shrink wrap. And I was all excited to go drop a chunk of change on a new ignition switch or starter relay. :yes: I guess I did end up getting an ignition coil and ICM somewhere along the process, but for $20 I'm glad I did it now instead of later.

You're supposed to drill the hole on the bracket attached to the CPS, not the hole on the bellhousing, right? I took a file to the bracket hole and expanded it enough to get the CPS closer, and now have 0.5 to 0.7 VAC while cranking -- still no start. [i'm guessing you meant your Tip#7 not Tip#8]. I'm now looking at my ignition coil and module. My coil has a secondary resistance of 2.198 kOhms, and a primary resistance of 0.4 to 0.5 ohms. The secondary seems low. I'm not sure that my ICM is getting a good timing input from the ECU (based on my guess of what a multimeter should show for a square wave). I'll throw an oscilloscope on it within a couple days to verify.