Gr8Dain's 4.0/aw4 swap from a 97 XJ

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
Sigh. I took a break from work and decided to clean up some wiring. I added a dual bus bar set up and ran a hot from the starter post to one and a wire grom tge battery to the other side. I used 8 gauge wires. Not sure if I needed that thick, but why not. And I am tryibg to do it right by using a proper crimp tool and the heat shrinking wrap. Then I used some brackets to hold one of the wire looms against the firewall. I also ran a dedicated ground from the computer over on the driver fender to the bus bar.

Then for shits and giggles I attempted to fire it up. 😓 No bueno.

I am getting fuel pressure at the rail, but I am not sure about spark. I will do that testing another day. Too cold now and I need to get back to work.

I have my multimeter, spark tester and injector tester ready to go. I really hope I figure this shot out soon.

I may decide to build a little roof for the bus bars. I would hate for them to get wet.
 

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jpnmaine

Active member
CJ-8.com Member
City
East Wilton
State
ME
Beg borrow steal a fuel injector Noid light test light. It will tell you if the computer is sending pulses to the injector. An old timing light helps when alone to verify spark.
 

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
Beg borrow steal a fuel injector Noid light test light. It will tell you if the computer is sending pulses to the injector. An old timing light helps when alone to verify spark.
I have access to an injector tester. And I have a spark tester. So I will get busy troubleshooting when I get another break from working.
 

gr8dain

Scrambler Junkie
LIFETIME
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City
Ashburn
State
VA
Ok, just went out after ending work for the night and did some simple tests. When I crank the motor, zero spark. I tested the resistance of the grounding of the computer and it was 0.8. So not bad. I also tested all of the circuits in the fuse box in the harness. 12v coming and going to all of them.

To me this is pointing to a crank sensor that is bad. I am inclined to just get one and see.
 

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
I have been fighting the no start. I replaced the crank position sensor this morning. No luck. But I know I am getting 5v to it. I confirmed I am getting 5v at the cam sensor in the distributer as well.

My son got home from work and I asked him to crank it while I looked at the test light connected to the output of the coil. While cranking, no light. But when he stopped and let it go back to ACC, I saw a light of electricity go between the coil and the distributer. Hmmm.
 

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
So based on what I am reading from the 98 XJ service manual and the wiring diagram, I am supposed to be seeing 12v at the wire toward the block in the plug to the cool. I am not getting that. So for some reason, I think the Auto Shut Down relay (ASD is keeping power from going to that plug. Maybe there is a break in the wire. Maybe the CSP or Cam Sensor are not sending a signal back to the PCM. Not sure. Have I said yet that I HATE ELECTRONICS!!!!! ?
 

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gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
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City
Ashburn
State
VA
A carb and HEI does wonders. :giggle: Feel you pain though.
Right? I lived with a crappy carb for 10 years. The HEI gave me enough troubles though. Once this is running though ........ at least that is what I hear.
 

jammer1

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Maple Hts.
State
Oh
:fingerscrossed: May you have better luck with fuel injection than I've had on my 2 work trucks. When it works it's nice. If it develops a problem that's intermittent and the mechanics can't track down it's enough to pull your hair out (unfortunately I don't have enough to pull out).:rotfl:
 

spankrjs

Scrambler Junkie
LIFETIME
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City
Biloxi
State
MS
Right? I lived with a crappy carb for 10 years. The HEI gave me enough troubles though. Once this is running though ........ at least that is what I hear.
Sometimes we just trade up from easier/simpler systems to keep running/repair/diagnose, too much more complicated systems.

I still love my OBD1 MPI over my carbs, though!!
 

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
I am wondering if the PCM I got with the 98 harness had the chipped key enabled anti theft system. I thought the seller said no, but ......

If so, then I will be looking for a different computer.

Off to work on something else today. Maybe TJ fenders on the rear or install the GMRS radio.
 

gr8dain

Scrambler Junkie
LIFETIME
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City
Ashburn
State
VA
I got it to run today. I wish I could post video. But the distributor was 180° out. Then I had to bypass the ASD relay and it fired right up. So I am happy. But I need to find out what is keeping the ASD from letting power get to the coil. My mind is swimming with possibilities. Somehow I need to test sensors to see if they are sending signals to the ECM. Or maybe it is a ground somewhere. Or ..........
 

gr8dain

Scrambler Junkie
LIFETIME
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City
Ashburn
State
VA
Thanks to @bigwalton for walking me through some tests this morning. We discovered that the socket for the ASD relay was getting switched power to pin 86 but there was no ground to 85. I ran a test dedicated ground to the wire for pin 85 and somehow got the Scrambler to run after coaxing it with the ignition. But after letting it run a little, I turned it off and can no longer get it to start again.

I am cold and hungry so I cane back into the house to grumble a but. Maybe tomorrow I will be able to get it to start again.

Oh and while it was running, the heater core was dumping coolant onto the passenger floor and then to the ground. So I have bypassed the core having the heater hose make a loop under the hood. Why do I do this to myself?
 

gr8dain

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
Ashburn
State
VA
So When the motor was running earlier today and I pressed the throttle, it died when I let it go. Since the computer was throwing throttle position sensor errors, I decided to make a run to the auto parts store. Installed a new one and so much better.

Also note the gauges. The temp is reading about 150 when ice cold. Then after run ing less than a minute it is hitting around 250. And the thermostat has not even opened. I am guessing that the old CJ gauge I have may need to be swapped out for one for the newer motor. @bigwalton can you confirm this?

Oh and I wanted to test the transmission. So I shifted between gears. Appears to be working. Yay.

I wish I could post videos here. Oh well.
 

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