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Comanche has no spark.


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Hi I have a 1987 jeep comanche base, my father purchased it for my project truck. The truck has a rough country lift besides that it is original. We are reaching out for some help. I drove the truck into the garage bay, eliminated the C101 connector (per Cruiser's excellent instructions) and now it will not start. We started with the red/yellow to red/yellow wires after we spliced them back together we tried to start and the truck would not start so we continued the C101 elimination and still no spark. I replaced the crank positioning sensor and still do not have spark. There are 2 rogue wires near the fuel injectors they pulled right out of the wire loom but did not have a connector on them purple/wht and wht/blk I'm clueless about the two wires. I also cannot hear the fuel pump cycle. Any help on this no spark/fuel issue would be greatly appreciated. Like I said it all worked before I cut the first red/yellow wires. We triple checked all our solder connections and color code.

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Cruiser54, Thanks I'm headed to the garage now to test the new CPS. Any Ideas on the two wires that are not terminated in the wire loom? The wires are on the throttle body side of the C101 not the fire wall side. I cut a C101 out of a cherokee and the wires in that loom are not terminated either.

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Cruiser54, I tested the new Hastings CPS and received a .18 V/AC reading (Booo). I am going to reinstall the old CPS and check Voltage through to see what I get and clean the coil per your tips. Thanks for your help

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I plan on tackling the whole list cruiser put together as this is my sons first vehicle and I would like it to be in factory like condition. He is 15 so we have time to get it straight. Thanks a million for your replies.

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I plan on tackling the whole list cruiser put together as this is my sons first vehicle and I would like it to be in factory like condition. He is 15 so we have time to get it straight. Thanks a million for your replies.

I got my first truck at 15 and it was a project for me and Dad. I learned alot. 

 

Suggestion. Begin with Tip 1 and continue on to 5. 5 will tell you if 6 is needed. 

 

If the CPS is coming off again or a new one needed to go on again, do the drill mod.

 

Tip 27 will help develop soldering skills along with logic and organization skills for your son. 

 

any questions, post 'em up!!! 

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Update: C101 Eliminated, grounds refreshed, new NAPA CPS holes drilled, and cleaned coil and connectors. I'm stumped. I still have  no spark and the fuel pump is not cycling. The CPS is reading .27 to .38 V/AC. Any thought on where to go from here? I still have two wires from the C101 elimination that pulled out of the wire loom on the throttle body side but looks like they were never terminated from the factory.

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I had an extra ballast so I switched it out. I will bypass it tomorrow. I will find out how to test the coil and proceed to test. I know there is a positive and negative terminal but don't know the test perimeters, I should have tested it when I had it out to clean it. Thanks for you help. 

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I swapped in an AW4 for a BA/10, I had to get the whole wiring harness from the donor...I had two wires that I could not find a home for.  They turned out being sensor grounds which are packed into the harness with a crimp and some kind of weird factory glue/paste.  I was getting no spark and a very minimal reading at the CPS.  I did the "sensor ground upgrade" mentioned in Cruisers tips.  BAM, fired right up (after literally MONTHS of messing with it).

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I swapped in an AW4 for a BA/10, I had to get the whole wiring harness from the donor...I had two wires that I could not find a home for.  They turned out being sensor grounds which are packed into the harness with a crimp and some kind of weird factory glue/paste.  I was getting no spark and a very minimal reading at the CPS.  I did the "sensor ground upgrade" mentioned in Cruisers tips.  BAM, fired right up (after literally MONTHS of messing with it).

Tip 6. 

 

I just reviewed the wiring diagram and what Paradise says makes perfect sense. 

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I traced the two rogue wires, they go through the fire wall to the ECU but do not terminate they come out of the loom and are taped to the loom. I believe they may be for cruise control that I don't have. I replaced all the relay's (they are salty).Still no spark or fuel pump. 

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You are correct Cruiser but these are not terminated at either end. Now that I figured out that rogue wire issue do you have any idea why my CPS voltage is low? I drilled the mounting hole out and readings got better but not above .4 V/AC and still no spark or fuel. I have the means to test circuits but don't know what circuits to test or where to start. My grounds are reading .1 to .2 Ohms. I have 12.5 volts on the thicker yellow wire at the coil. I do hear a hummmmmm near the distributor when the key is on. Do you think it could be in the distributor? 

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You are correct Cruiser but these are not terminated at either end. Now that I figured out that rogue wire issue do you have any idea why my CPS voltage is low? I drilled the mounting hole out and readings got better but not above .4 V/AC and still no spark or fuel. I have the means to test circuits but don't know what circuits to test or where to start. My grounds are reading .1 to .2 Ohms. I have 12.5 volts on the thicker yellow wire at the coil. I do hear a hummmmmm near the distributor when the key is on. Do you think it could be in the distributor? 

All the distributor does on these is distribute spark. That thing a ma bob inside is for syncing the injectors. Unplug it and see what happens. 

 

Do you have 2 connectors in your harness to plug the CPS into? 

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I'm thinking about unbolting the CPS taking off the dust cover and reinstalling the CPS without the dust/debris shield. It only takes 3 min to take off the CPS. I'm getting desperate. Do you think it could be the PCM? I have read a post that cruiser walked someone through this process but dummy me didnt save it.   

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I'm thinking about unbolting the CPS taking off the dust cover and reinstalling the CPS without the dust/debris shield. It only takes 3 min to take off the CPS. I'm getting desperate. Do you think it could be the PCM? I have read a post that cruiser walked someone through this process but dummy me didnt save it.   

And I don't remember it!! Crud. 

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I believe the wires I found were the factory installed CPS wires to the ECU. A recall went out P007 and the CPS to ECU plug was rewired. My ECU has Bendix written on it not Renix, does this make a difference? I'm just trying to figure out this truck's problem. 

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Bendix is fine on the ECU

 

Here's my concern.

 

When the rewiring was don for the CPS to go directly to the ECU per the bulletin, not a recall, the tech was to cut off the no longer used harness plug. Lots of times they were left on and you could unknowingly plug a perfectly good cPS into a harness that didn't go to the ECU.....

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  • 5 weeks later...

Thanks for all your help Comanche club!!! I replaced the computer under the dash and she fired right up. Next time before I cut wires I will unhook the battery (I should know better). 

 

Any idea's on where to purchase or who has quality rockers and floor pans?

 

Thanks again for all of your help.

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