LoTGoD

No, I was not. The TSB I'm referring to has to do with the CPS wiring. Your CPS may ohm good, but these trucks have too much resistance in the wiring between the ECM plug and the CPS plug. Replacing just the CPS does nothing for this defect. I'm not sure why roll starting worked for me, but I SUSPECT the reason it worked is because during a roll start my crank was turning faster than during a regular start. Perhaps this faster crank rotation provided a readable signal for the ECU to work with to get the truck breathing on its own. In any case, it wouldn't start with the starter, no fuel, no spark, but it would roll start every time. I had a dealer perform this TSB, and now my mother is DDing the MJ while I'm overseas with no issues. I won't push the issue any further if you think it's a waste of your time, but a roll start is free. Give it a shot... EDIT: Here's a link to the TSB. http://wagoneers.com/XJ/tech/WIRING/CrankPositionSensor/CPS-87-90-update.pdf I did a home-brewed version of this that made the truck behave for a few weeks before it fell victim to the cheap crappy connectors I used. I just drilled a hole in the firewall, cut the CPS wires, cut the ECM wires, and spliced them together. Hmmmm....interesting point. I would give that TSB a shot, if I didn't already verify Ohm readings at the ECU connector. There was barely a 5 Ohm loss from the connector to the ECU, and that is well within spec. I'll try the rolling start as soon as I can get it out of the garage!

Starter is good. Plenty of cranking going on, just no spark and no fuel :D

Jeff, No engine swap. Mine had the 4.0 Renix in it when I got it. Engine harness and ECU harness are from Pat's 89 manual trans parts Jeep. Interior harness is also the new one from Pat. All engine side grounds are hooked up and connecting bolts are tight.

Were you getting any spark or fuel? I'm getting neither, so I doubt a roll start will help me.

That's a beauty! I was introduced to bikes at an early age, and ran in to the same motherly resistance that you had. My father has had his 1968 Triumph TR-6R Tiger since 1972. In 2006 he purchased a (still new) 2004 Triumph Speedmaster. By default, I was given the '68 to ride, with much ranting and raving from my mother. Its a great little 650, bored over to a 750, but with my height and weight (5'11", 250) I just feel too big for it. I've seen my share of Harley's, and they are nice bikes, but just not for me. One day I'll inherit the Speedmaster. I think the Triumph's are similar to the Buell's, in that they are rare, but you don't see them going for anywhere near as much as a Harley. This will be my next bike: Triumph Speed Triple! Very similar to the Beull!

Nope...no miles...and still no start! I pulled his ECU out, and swapped it in. Nada, zip, zilch, nothing! Mine in his and his fires right up. That lets me assume my ECU is good. Sorry Wildman...looks like I won't be needing that one from you after all. I'm stuck again. Let's recap what I've done so far: [*:b21eiqep]Replaced CPS (original one was melted a bit from contact with the header) [*:b21eiqep]Tested and verified new CPS (read 202 Ohms) [*:b21eiqep]Removed coil and verified in another MJ [*:b21eiqep]Removed starter solenoid and verified in another MJ [*:b21eiqep]Verified voltage in sync signal in distributor [*:b21eiqep]Verified fuel pump, B+ latch, and O2 heater relays [*:b21eiqep]Tried both (good) engine and ECU harnesses Let me pose 2 questions now: 1. Does it matter in the least that the steering column in it is out of a an auto? I removed the kick-down cable that attached to the column that allows the key to be turned back when the auto was put in park. I now have to manually push that rod back up in towards the steering wheel to get the key to release from the run position to the off position. Is there something missing here that would cause it not to start? 2. What is the minimum in-cab wiring that I need to have it fire up? I currently have the 4 connectors on the steering column (2 connectors that I believe are the power that goes to the starter, 1 is blue, and one is black, and connect to the top right of the steering column) The other 2 on the column are the very wide connector at the right most portion, and the headlight hi-beam connection. I also have the fuel pump wiring and rear lights connected. I have no gauges, nor any other connector attached. I have a ground wire connected directly from the battery to the mounts of the ECU to make darn sure it is grounded. Is this minimal setup good enough for it to fire up? Again, I appreciate all the support I've had on this. I'll get it, as I am slowly eliminating everything under the sun!

They are called a "wheelhouse" by all accounts that I have seen. We sell 97-up...but that seems a bit pricey for some plastic liners... http://www.4wd.com/search.aspx?PN=1&kw=wheelhouse

That is VERY good to know Jeff. So if that is the case, then the auto ECU's are backwards compatible with the manual tranny, but not the other way around? I'm confused now as to why there would 2 different ECU's....

Will an ECU from an 88 auto work to at least get my 90 manual started? I have access to a friend's MJ that was originally a manual, but was converted to an AW4. All I am looking to do is get it to fire up and verify that my ECU is bad. Will this be an issue if I put his ECU in my MJ? Thanks! Aaron

That should increase with Ian Johnson from Xtreme 4x4 as part of the mag now (part owner) Since he is located in TN for the TV Show, should get more stuff from the east in there.

Sure! Just bring some beers over and make sure you take your muddy boots off at the door!

Gimmie a break Eagle...I'm still trying to get mine to make it out of the driveway TO the road! (then to the trail!)

You are correct! Guess who did their (basic) website? :brows:

Fusible links would feel "mushy" if they were fried, correct? If so, I've check them all, and they feel solid. Will test for continuity tomorrow. Started relay was swapped with my friend's 88 tonight. Mine started his, his didn't start mine. Pretty much everything was connected. All links looked good. Will check for current flow tomorrow. Had buddy's 88 MJ over tonight and double checked in-cab connections. All sync with mine. My dad suggested the CAMshaft Position Sensor, but since there is no injector pulse, should I bother with that at this point? Tested injector wiring during crank, and no voltage present at injector wiring connection. I'm beyond frustrated at this point, and have ended up laughing each time I try and crank it :yes: Not sure what next steps to take....

Borden, I am in the same boat as you right now...about to call it quits on an almost finished project MJ. If it weren't for the fine folks here with their help and encouragement, I'd probably be setting the thing on fire in the yard tonight. Keep persevering, and you'll get that sucker on the road yet! Aaron

You aren't going to find a new one. Do a search on it. This topic usually gets covered once or twice a week around here. Common practice is to either find a working (used) replacement, or remove it from the braking system altogether.

According to the original exchange between Pat and myself, it came out of an 89 MJ. Yep, new guy on here that bought an MJ and live about 5 minutes from me. His is an 88 I think, that was manual, but was converted to an auto. It can't hurt to look. But with my no fuel issue, wouldn't it make more sense that it is something else at this point? I'm not doubting your motives, just assuming that it is my lack of remembering where [X] connectors went on the install of the new harness. Since all else has failed at this point, I'm just going to do more thinking and research before I move any further. Want to make sure it isn't the obvious thing now, then move on to the CamPS. Man this is frustrating.... :headpop:

I'm pretty sure I do, but there are subtle differences between the harness that Pat sent me, and my original 90 harness. some of the connectors on the engine side of the fuse block connector are different, requiring a different ECU/injector harness. I did see this on JU, but since the motor ran right before I pulled the original harness, I didn't feel that it was something that "had" to be done to get it to run right now. Nope. I haven't touched anything mechanical with the engine since this build started. I feel that my downfall was pulling the harness 2 months ago, rather than waiting until the replacement unit arrived. You think you'll remember where everything connects...and then I see I have some "extra" wires that aren't connected, and can't remember if they were connected on the original harness or not. I plan to get some pics of the ones that I don't have hooked up right now, in the hopes that someone will be able to tell me "Those need to go here..." or "Those aren't used in your application..." Haven't done this yet, as I am not getting spark out of the coil at all, so I figured this wouldn't be applicable. This is the next step. I've cleaned all contacts. Used grease sparingly on those circuits that I felt were the direct cause of the problem. I haven't really done anything substantial since last Thursday. It was a nice break over the weekend, but in the end, all I really did was sit around thinking about what the problem might be. I think I mentioned this previously, but I have a friend with an 88 MJ that I am going to ask to borrow for an evening. Plan to pull his lower dash stuff out and see if I can see anything on his that doesn't look like mine, connection-wise. Thanks for all the help so far, and the nice words of encouragement! Aaron

What a long weekend... After trying Wildman's suggestions (I do have a solid ground at the ECU) I am still back to no spark and no fuel. Both ECU's are #5429. I've opened both of them up, and there are no blown caps, no burn marks on the boards, nor are there any tell-tale signs of a power surge. I've pulled all wiring out and replaced it with my old corroded harness that did fire the engine before all of this began. I've decided that I must be overlooking something completely obvious at this point. I have to not be hooking something back up when I install the in-cab wiring, as the entire motor harness has everything connected. What should I do? My thoughts were to head to a local yard and tear in to an XJ dash to see where everything is connected and duplicate that back on my end. I'm feeling pretty helpless at this point, and have stopped all other parts of my build until I can get this corrected. Any more help or direction is greatly appreciated. Aaron

My WJ MC and booster are in place, but not road tested yet. No WJ proportioning valve in mine, just the stock MJ with the rear bypass blocked off.

I paid $600 for mine, and it is missing the entire driver side outer knuckle.

Beautiful write-up! :bowdown:

Well...Ohm's read 221, so the sensor must be good. I replaced the engine harness, and still got nothing. My logic at this point leads me to believe I missed something that needs to be connected under the steering wheel for the ignition, as I am getting +14 volts at the coil with the key in the run position. Still no spark while it is cranking. Doesn't seem to be sending fuel in to the cylinders either. Have a buddy with an 88 MJ that I am going to look under the dash and steering wheel tomorrow to see if anything jumps out at me.

If you've got time, and cash, head over to Feezles just inside PA near Unity and East Palestine. They have a white tailgate that looked to be in good shape. Not sure about the fuel tanks.

Thanks for those suggestions Wildman! I guess that will be the start of the testing tonight. Per your suggestion of testing the OHM's...we are talking about testing across the lead wires of the sensor itself...the male leads that come out of the bellhousing, right? The reason my tester was acting up is that the wire broke off the positive contact point, so I am left with just a bare wire to hook it up. I'll buy some new test leads tonight and see if that makes a difference. Once I pull the ECU and check, if it is bad, I do have a spare to hook up. Shouldn't make a difference what year the ECU is from, as long as it is a Renix ECU? 87-90 should be interchangeable?