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Not getting spark after rebuild


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The truck was running fine but the block had JB weld on the block. After the install I am not getting spark from the coil to the distributor.  We switched out the coil as well as what i am suspecting is the module underneath it, from my current daily which i know is good. Still nothing. We used a test light and went from my daily (which is the exact same engine) and tested the same wires on both trucks. They were both similar in responses. 

I marked the picture so it was easier to explain what we have tested so far to make sure.

we have power to the red, ground to the purple, nothing on the brown, ground on the blue, and nothing on the green. 

the red had power on both trucks.

the purple had ground on both trucks.

both had nothing on brown

The brown has a connector where it goes from two to one under the shrinkwrap on one truck.. i didnt even check that on the other.

the blue on my daily pulsed while the truck was running and one the other it stayed solid while the key was turning over.

 

we used a spark detector on the wire from the coil to the distrib. and from the distrib to the 1 cylinder. nothing on each

 

Any advice guys? I am stumped. Thanks in advance for any help

 

Edit: we also checked the fuses and made sure the alternator was hooked up correctly. 

 

 

FullSizeRender.jpg.469645b112d80745dd68d6628e863d8a.jpg

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We need more info. You said "rebuild," but you mentioned JB Weld on the block. Did you rebuild the original block, or did you build a junkyard engine?

 

If you used a junkyard engine, what year is it from? If it's a '91 or newer, whcih flywheel did you use and whick crank position sensor did you use?

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The engine is from another Comanche i bought same year and model. Sorry for the confusion.  I just stripped the old block with the JB weld on it and put all that stuff onto the rebuilt motor since the old motor was actually running good just busted. 

 

The cps is new. it is not a high altitude one, nether was the old one. I haven't tried reinstalling the old cps yet. Could the cps be bad from the factory?

 

I cannot find any loose connectors or grounds but i possibly could be looking in the wrong places. I'm sure its something simple i am missing but i am udderly stumped

 

The only things i replaced are the injectors to the four port, knock sensor, o2 sensor and the cps. everything else is what came off of the old motor straight to the rebuilt

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I replaced the new cps with the old one. And nothing. I do not have a ohm meter and my multimeter doesn't do amps for some reason. So I'm on my way to but one. I had a Mechainical oil psi gauge hooked up. And thought that could cause problems with the sending unit not being hooked up so I replaced that as well

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Slow down on firing the parts cannon at your Jeep and do some diagnostics. The meter you need is $5 at Harbor Freight. 


Or free with a coupon if you buy something else, like this past weekend.


Sent from my iPhone using Tapatalk
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Hahaha thanks for worrying Crusier. I had most of these new sensor already before getting the motor back from the builder. Which this is off topic but it took the guy almost 6 months to do?! it got machined within the first week then set on a stand in the corner under a cover while these other big cubic inch motors where in and out in the same week. I guess i wasnt trying to go fast enough or something :brickwall:

 

Back to the problem. I went back over the whole harness from where it leaves the fire wall to the passenger side of the engine bay. I do not see any wires that have missed. I got a newer meter from harbor freight (mine was found/bought at a pick a part a few years back) and i must not be using it right because no matter what setting i am on when i spin it over i am getting nothing. now i know this is a useless post, i am just trying to keep everybody updated that has offered help. I am gonna ask a co worker to come over and help me figure this out. I just wanna hear it run!!

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7 hours ago, cruiser54 said:

Are the wires soldered or butt connectored? 

they were butt connected and i went back last night as i was following the harness and anything that looked sketchy or even butt connected i soldered and shrink wrapped. My meter shows i have voltage coming from the battery. 

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15 hours ago, DirtyComanche said:

 

The leads on Chicom garbage like that often are supplied open, to protect the meter and you from actually accomplishing anything.

 

If people would stop buying the garbage at Harbor Junk it would dry up and go away. I've never been in one and it's number one on my spam list.

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Alright I got it to run!!!! After I redid all the connections and cleaned the grounds it fired right up. Actually fired up on the second  rotation of the engine with one of the spark plugs pulled out. I had not tried to start it since I changed all of those connections I wanted to wait till i had a extra hand to read the colt meter.  My co worker came by and took one of the plugs out and asked me to turn it over to see if it wasn't getting spark and bam! Now she's purring like a walrus. Thank you for all the help!!

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