RyanL

First off very nice truck! Second, I would try replacing the track bar first. I had the same problem on my Jeep and after replacing nearly every component it turned out to be the track bar.

Good job with the tank! The shackle was a great idea! Be sure on your first fill up that it does not leak! If so it will need to be filled with scrap plastic (plastic welder kit). As for the no start problem remove the door switch and try again. The lights will stay on but it should not affect performance if it was indeed the problem. It could also be a wire on the loom being moved onto metal when the switch is depressed. Your build is coming along great! Ryan

Thank you! And it has been driving great since it was put into service!

First update in awhile! The bumper is welded, painted, mounted! Should have the truck permanently in service on Sunday!

We had the bed off for the axle swap as well as the gas tank installation. It made it easier to be able to work from above by far, The axle swap is easy just the U bolts and the leaf spring bolts and the axle rolls out. The gas tank won't fit unless you jack up the truck on one side and slide it in (at stock height at least). Both need to be done, but I would recommend doing the axle swap then the tank. The gas tank mounts are on the bed but we temporarily strapped the tank to the frame rail to run it while we worked on the bed. It also helped to have the bed off when we were dealing with the clearance issues with the tank (easier to see it with the driveshaft in and the bed off). If you do the axle swap then the tank, you can hold your old driveshaft up on the new axle and check clearances. Just some thoughts, Ryan

Like Alexia says, the whole system must be functioning for the light to stay out. It takes 3 ignition cycles without fault for the airbag light to go out on its own if the system is functioning. With non deployed airbags installed, the only two things besides wiring on the circuit are the clockspring and airbag module. If you connect the airbags and the modules, and start it/kill it/repeat three times and it does not go out, either the clockspring or module is bad. We sourced an extra of each from the PAP and I replaced them one at a time, did the 3 starts. I ended up having to replace them both and the light finally went out. Be careful with the clockspring, as the tabs and center portion break EXTREMELY easily. Best of luck!

What he said^^^

Thanks man!

Thank you! The idle problem has still not been tracked down but it may be gas sender related: http://comancheclub.com/topic/39846-fuel-flow/ I already have the tank pulled out and after repairing the hole here in a minute, we will immerse the sender in a full bucket of fuel and see if it stutters. If it does I will replace it and go from there. If it fixes the idle problem that would be super! If it doesn't stutter then it was getting air from the tank somehow (not seated, or the hole in the tank). The belt just needed to be tightened a lot :doh:

Fabbed entirely new straps. Got some mobile home tie down straps, cut three 50 inch pieces, welded the MJ strap "T" fittings to the end, bent the other end 90 degrees, folded it over for added integrity, drilled a hole in it and used the existing MJ "J" bolts. The XJ bolts can be used as well but my father had bought galvanized ones for the MJ and I reused them.

It helps to a degree, but with literally square everything, the MJ was never an aerodynamic truck haha :rotf:

Any help is good help! Even if it is tired help haha! I honestly hope it is the problem, because we have been chasing this problem for weeks. I am pulling the tank down tomorrow, and repairing the hole I mentioned above, and if that solves the skipping, sweet! If not I will replace the sender. I am almost convinced now the skipping is not normal. As you say, seeking other opinions is a must. These confirm my suspicions!

That would be a possibility, part of the reason the tank had to be drained was for a repair to a small hole (could be introducing air to the sender), but wouldn't it pulse all the time with a low fuel level if the sender wasn't submerged completely? In the beginning it had a solid flow. But with the hole in the upper corner, it is a valid possibility. When the tank is repaired it should give us a better picture. And the timing test went as you said it should. After more research my father and I discovered that the O2 sensor behind the cat prefers a regular 2% oxygen to run idle correctly. It sends the information to the PCM and the computer adjusts the idle from there. If the sensor gets more oxygen than it wants through say a bunch of clamped fittings on the exhaust pipe some people had to splice together on a 97+ conversion (ahem :doh: ) it will forced feed the engine fuel, not knowing where the extra oxygen came from, reading the engine as running lean. The connections were professionally welded today, but with the hole in the gas tank, we cannot be sure if it was the problem or if it is another thing because it is not safe to run the truck. But it could also be a bad sender. When the tank is repaired and the sender replaced it will hopefully lead to some answers! If the fuel skipping and engine performance are related it will answer a lot of questions!

That's the thing, it seems to be working fine (energizes on key to RUN, runs when the car does, etc.) but the flow is what I am worried about. Is the "skipping" normal?

The trim you mentioned earlier in the thread is the drip edge. It is used to prevent "wind water", or water pushed by the wind when you are driving, from getting in the doors while you are moving. And the MJ has its own trim, with 5 (or 6) holes in the frame where push pins hold it in.

Alright gents wanted to scratch an itch here, I have recently completed the 99' conversion on my 89' MJ. I used the 22.5 gallon Dakota tank with a 98' Dakota fuel sender, wired in to operate with the 99' layout. (The 98' sender is the only type of sender that has the correct polarity to read on the XJ fuel gauge correctly besides the XJ tank and sender). So, saying all of that, is this how the fuel is supposed to flow? The tank had be to drained to install the Dakota heat shield, amongst other things, and the tank is a lot easier to handle, mostly empty of course. The fuel pump relay was jumpered with a wire to induce constant fuel flow to drain the tank before removal. The fuel rail reads a solid 47 P.S.I. pressurized, so I was just curious if this is a indicator of a bad/spotty fuel sender, or if the fuel flow is staggered for the injectors or something? :dunno: We have been trying to chase down an intermittent engine "hiccup" and could this be the cause? Thanks in advance, Ryan Edit: The line was clamped BEFORE the fuel filter.

It is the triangular gap in front of the X member. The top of the differential is in the bottom of the picture. The wood is a temporary spacer for the gas tank. With the Dakota tank, the fuel sender is taller than the tank itself, and must be spaced off the bed to prevent rubbing. The wood was a "measuring stick' sorts to see what size square tubing I needed to buy. It also gets the vehicle mobile, which I need to have, with my return to college fast approaching.

Got the charcoal box mounted today which was the last miscellaneous piece needed to go on. Here is where I chose to mount it: Extended the lines, and here's how it came out: For all intensive purposes the truck is generally "put together". From here on out it's mostly just problem solving as it comes! Some shots in the sunshine :rock on: More to come! Stay tuned!

I can't wait to start driving it around! Yours is gonna be a lot cooler than mine haha the lift and rims are sick!

We got lucky and knew a professional painter who lived on our street! Gave us a lot of advice on what grade products to buy and such. He's one of the best painters I have ever seen!

Update time! Got the bed and tailgate on today Sorry for the angles, the truck cannot be moved until the tank can be strapped on, which will take place tomorrow. The bumper is a JCR offroad DIY and will be installed later as well. Almost there :clapping: Stay tuned!

Everything on the MJ is standard for the 1999 year XJ except the gas tank which uses the existing wiring, but just a different sender (1998 Dodge Dakota). As for the routing, we followed the wiring as it went. Ex. The injector wiring rail (plastic rail next to valve cover) has three mounting pins that fit over the head bolts by the intake, and the sensors fall from there. Some wiring may not be in the exact position as the donor vehicle, but wouldn't that lead to the problem occurring ALL the time, instead of at random? The CPS routes right off the end of the aforementioned injector wiring rail, and goes down the edge of the intake to the CPS. The cam sensor is part of a cluster of connectors and can only be routed one way.

Ahh I understand now. Tomorrow, I will pull off the aux fan and repeat the test through the RPM range and post the findings. If our results don't match up does that indicate a faulty ECU?

We used a timing light on it today and this is what we got. The white mark is TDC on the harmonic balancer. Is it supposed to move around that much? Any thoughts? The engine ran great for as long as we were out there (30 plus minutes) and only threw the code P0138 (High O2 sensor circuit). This problem is a tough one...

Update time! Got the bed and tailgate painted today! Also as an after thought, the tail lights got a coat of clear as well! I think they came out great! If all goes well the bed will be on tomorrow! More to come! Stay tuned!