5.2 5.9 Magnum Guys, need Wiring help, no spark

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streetdak

streetdak

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I posted this on another forum, but figured I'd try FABO also, any help would be awesome!

I've been doing a magnum 5.9 swap in a 73 dodge dart. And I am having issues getting spark. So let me give as much information as I can to see if anyone can give me a hand.

I had a complete donor vehicle to work with, a 98 Grand Cherokee 5.9 Limited. Reared and interior is trashed, so it made for a perfect donor vehicle. This motor ran like a top and I fired it up the day I pulled the motor. I pulled the motor out and mated it to my 904 trans. As for the wiring, I of course used the entire engine harness with the black and white PCM connectors that is basically 100% independent of the Power Distribution Block. I cut wires at both sides of the firewall and then removed the power distribution box and grey harness side.

I now have the motor in the car, the harness (black/white) installed and even the power distribution center and harness (grey) hooked to my PCM. All the grounds are in place, alternator is hooked up. I am using my Dart's starter relay and wiring so that I did not have to modify the wiring since I moved the battery to the trunk.

Now, I have not hard wired the car, I have been working with the harness to make sure I got spark before I routed wires and lengthened anything. Here is what i do have. At this time I have not bothered with an ignition hot, I have just routed everything to a constant battery + and connect the battery to test as If I were turning on the ignition switch. I know that most of the stuff in the power distribution is not utilized such as the horn, high beams and so forth, so I have not bothered any of those circuits.

Right now, I do not have the fuel pump (on green/white) ran to the fuel pump, but I do have all the ignition on (orange) wires from the ASD/FUEL and PCM ran to the constant power, I also have the blue/grey wired to the constant power at this time. When I hook up the bat, confirming with a test light both the ASD and the Fuel Pump relays cycle for 3 seconds and the cut off. So I know the PCM is grounding the circuits upon ignition. But When I go to start the car I am receiving no spark. Injectors seem to be cycling, as I hear them and they also have power when battery is hooked up.

Upon the swap, I never messed with the crank sensor I don't think that there should be any reason to be bad as well as the cam sensor. This motor fired about 6 months ago without any issues. I think it has to do with my wiring. Does any one have any idea what I missing? I know when I first started I bypassed the ASD by grounding the pink/white wire and I would get constant hot at the coil, but no spark. I think it has to be something that I just don't have right.

More notes, O2 sensor is plugged in, trans wires and 4x4 are still attached to the harness, but not hooked to anything besides the neutral safety switch is grounded (black/white). Not sure any of this matters, but the more info the better. Also, I have not hooked up a comm port or a "check engine light" yet but will be doing that on Monday. I really think I'm close, not sure where I went wrong, any help is appreciated!
 
I was just reading about this yesterday in a jeep forum. Apparently if the PCM doesn't see the crank spinning before the 3 seconds are up it turns off the relay.
http://www.jeepforum.com/forum/f12/project-magnum-yj-1011186/index19.html
From post #279, he didn't have some wire hooked up....." Within a few minutes we found that the sensor return (PCM pin 4, black/light blue) was not tied into the harness."

The post also says something about it being in part of the harness that runs to the trans..."
It was going to the trans, TC, etc, but not back to the PCM. Wired it in, and lots of spark!"

Also on pg 17, post 247 mentions something about PCM needing a signal from the neutral safety switch.


I should be a little more help after setting up my wiring this weekend ;)
 
player1up said:
I was just reading about this yesterday in a jeep forum. Apparently if the PCM doesn't see the crank spinning before the 3 seconds are up it turns off the relay.
http://www.jeepforum.com/forum/f12/project-magnum-yj-1011186/index19.html
From post #279, he didn't have some wire hooked up....." Within a few minutes we found that the sensor return (PCM pin 4, black/light blue) was not tied into the harness."

The post also says something about it being in part of the harness that runs to the trans..."
It was going to the trans, TC, etc, but not back to the PCM. Wired it in, and lots of spark!"

Also on pg 17, post 247 mentions something about PCM needing a signal from the neutral safety switch.


I should be a little more help after setting up my wiring this weekend ;)
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sweet. I know which wire he is talking about. I need to see if mine is the same way. I'll peek when I get home
 
Well, Mine runs.....Streetdak...Where are you??? :lol:

Nothing spectacular about the hookup. I did make sure that the neutral sense switch is hooked up, I did have a bit of an issue with splicing into the harness at the PCM vs at the power distribution unit. When I have everything cleaned up, I'll post full info with pics
 
player1up said:
Well, Mine runs.....Streetdak...Where are you??? :lol:

Nothing spectacular about the hookup. I did make sure that the neutral sense switch is hooked up, I did have a bit of an issue with splicing into the harness at the PCM vs at the power distribution unit. When I have everything cleaned up, I'll post full info with pics
Click to expand...

Congrats man! That's exciting!

I found out whats wrong with mine. After about 4 days of research. My donor had vtss (factory security system). It will let the vehicle start for 3 seconds and the die. After 3 consecutive starts, it goes into a saftey lock feature and shuts down the ignition system.

Well, me and my buddy started it about 3 times while it was still in the jeep when the harness was independent of the jeep. Hence, this is my issue. My wiring is correct, and I am not so crazy after all haha!

what lead me to this was my pcm started having power send issues because of the c1 black plug. I wired in a new plug, and duplicated the problem and the realized what my issue was. I'm sending it off to a place that says they can reset the vtss (once reset it needs a bcm to activate it, and unless activated it will work with no issues) and possibly fix the pin issue. So I hope, once I get it back it all will be in working order.
 
Good to hear you've got it figured out. I still don't know if my PCM has the security option.
As soon as I get the exhaust done I'll try again and see what happens. I started it a few times and it stalled, but I have open manifolds ( no O2 sensors hooked up yet ) and some vacuum ports open. I just wanted to see if I had the wiring at least partly correct... and beat you to the punch. :lol: JK, I'm still pretty far from the end...
 
Sees like a shame that we have to outsmart the darn computers to use the new engines in our classics. That said, I do enjoy the computer startup on my '02 Dakota, as opposed to "pump the gas pedal to set the choke and hope ya don't flood it" on my classics.

ATB

BC
 
64ragtop said:
Sees like a shame that we have to outsmart the darn computers to use the new engines in our classics. That said, I do enjoy the computer startup on my '02 Dakota, as opposed to "pump the gas pedal to set the choke and hope ya don't flood it" on my classics.

ATB

BC
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haha! This will be a challenge for me as well, i'm so used to 2 pumps and 1/4 throttle to start the car, so i'll have to fight the urge to not hit the pedal!
 
welp, just verified that the PCM I got has security enabled.... started a total of 5 times before it started not starting :lol:
So if you have the vin from the vehicle that the PCM came from you can use this site and someone will respond with the options that the thing came with....

AJB Security Group is the dreaded option on the list.

At least now I know for sure.
What company did you use to reprogram your PCM and what did they charge you? If you don't mind me asking.

oh, and I will NOT miss the pump,crank,stall,flood shuffle either :D
 
67Dart273 said:
...................Megasquirt................
Click to expand...


it is a nice system.... but $400+ bucks

my new pcm cost me under 200. and i just installed it with no luck of firing.

I then installed the new crank sensor and got this,

[ame="http://www.youtube.com/watch?v=dvQwUU9hk10"]73 Dart Magnum 5.9 transplant inital startup - YouTube[/ame]
 
my question is how do you re-use the magnum crank sensor with a 904 transmission? I know the bellhousing has to be notched but the flexplate has the ring gear for the starter on a magnum and the 904 has the ring gear on an LA series engine...
 
66plyValiant said:
my question is how do you re-use the magnum crank sensor with a 904 transmission? I know the bellhousing has to be notched but the flexplate has the ring gear for the starter on a magnum and the 904 has the ring gear on an LA series engine...
Click to expand...

The Magnum motors have their own flexplate that contain the trigger holes for the crank sensor. The only modification that the magnum motor's flex plate needs is one hole to be hogged out for the 904's torque converter to bolt up.

LA with automatic trans, the ring gear for the starter is actually welded to the torque converter, not directly connected to the motor. If you go to my build page in my signature it shows all the modifications needed for the 904

My bad, I just re-read your post, the ring gear on a Magnum motor with auto trans is on the torque converter just like the LA motors.
 
streetdak said:
The Magnum motors have their own flexplate that contain the trigger holes for the crank sensor. The only modification that the magnum motor's flex plate needs is one hole to be hogged out for the 904's torque converter to bolt up.

LA with automatic trans, the ring gear for the starter is actually welded to the torque converter, not directly connected to the motor. If you go to my build page in my signature it shows all the modifications needed for the 904

My bad, I just re-read your post, the ring gear on a Magnum motor with auto trans is on the torque converter just like the LA motors.
Click to expand...


some reason I remember the 1996 dodge ram I took apart had a ring gear on the flex plate, well if its not case and its still like the LA its an easy thing to bolt up

wiring isn't a problem for me I do it all the time
 
66plyValiant said:
some reason I remember the 1996 dodge ram I took apart had a ring gear on the flex plate, well if its not case and its still like the LA its an easy thing to bolt up

wiring isn't a problem for me I do it all the time
Click to expand...

It could of been a standard truck, maybe that would explain it? not sure, but good luck if your after this swap. Was a great learning experience for me and if I can help in anyway just yell!
 
streetdak said:
It could of been a standard truck, maybe that would explain it? not sure, but good luck if your after this swap. Was a great learning experience for me and if I can help in anyway just yell!
Click to expand...


thank you, maybe it was the jeep 318 I was mixing up with the truck 318, seems one of them was set up that way

wiring isn't much of an issue, just getting it in is the hardest, which won't be bad
 
another question is, your user name is streetdak, did you do a v8 swap on a first gen dakota? did you use shumacker engine mounts or just use a magnum engine or build your own?

a fella not far from me advertised a '90 dakota with an LA engine and he built his own mounts but won't share pictures
 
66plyValiant said:
another question is, your user name is streetdak, did you do a v8 swap on a first gen dakota? did you use shumacker engine mounts or just use a magnum engine or build your own?

a fella not far from me advertised a '90 dakota with an LA engine and he built his own mounts but won't share pictures
Click to expand...

yeah man! that was like 12 years ago! If i remember right, I used modified Grand Cherokee mounts with my 4 banger's brackets. To put it honestly, it worked, but it wasn't right. I was a 19 year old kid then and I was just learning. I eventually had an engine fire at the race track, and rebuilt the motor. Wound up having a buddy weld new mounts for me on the frame rails that used the 5.2 grand cherokee motor mounts, and then it got hit outside overnight in the parking lot while waiting to get picked up. I might have a pic some where of the mounts, ill dig around when i get home. Oh an it was a LA motor, the schumacher mounts are very nice!
 
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