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Discussion Starter · #1 ·
Hey guys,
Been having trouble with my YJ starting, now it won't start at all.
It cranks, battery is good and it is getting fuel.
I just changed the cap, rotor and ignition switch but still nothing. It seems like I am getting spark as the key is being released after cranking.
Any suggestions?
Thanks
 

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We had a simular problem. I take it that after you replaced the
cap and wires it wont start at all... The diagram in the manual we used showed the rotor in the wrong orientation. Double check that #1 wire is at the 1 position on the cap (look for the
1 on the cap. We went by the diagram position in the book and had #1 in the wrong position SO everything was wrong. Its worth a second check. Oh is it plugged in (coil wire) Ya we did that one too. Good Luck
 

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Discussion Starter · #3 ·
It wouldn't start before I changed the cap, rotor and ignition switch, that is why I changed them. Could the timing be the problem? The Jeep was running OK Friday, Saturday morning it wouldn't start, I don't know why. I had a si,ilar problem a couple of years ago, and it was a loose wire to the Jacobs Coil. I checked all the wires and even re spliced the connections, still nothing.
Thanks
 

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what makes you think it's getting spark as key is released? i believe coil gets voltage from different circuit while cranking vs running.

let's start out simple use process of elimination. take the cap off, see where the rotor is. leave cap off bump the starter, see if rotor moved.

we'll go from there.
 

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Discussion Starter · #5 ·
Thanks Scumby, Rotor / Distributor is turning.
I connected an extra spark plug to the #1 wire and held near ground. When key is turned to crank starter, no spark until key is released to run position.
 

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What year is the YJ? Does it have a 4.2 (carbed), 4.0 (EFI), or a 2.5 (EFI)? It makes a difference to answer the question.
 

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i'm still thinking it has 2 different circuits for starting and running. if it's a standard trans and you have the room put the key to the run position and have someone give you a tow to try to pop start it. if it runs it's gotta be in the start circuit, right?

or, if you have a voltmeter check for voltage at the coil + terminal to ground while cranking and in the run position. a digital meter will probably show OL if it's got voltage while cranking. an analog meter will just move the needle up and down, the voltage really isn't to important yet just whether or not it's there.

this all assuming you can reach your coil and it's the old cylinderical shaped one. good luck and let us know what happens.
 

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Discussion Starter · #10 ·
Thanks guys,
It has a manual trans, and I am getting juice to the coil. The yellow wire from the ignition switch? (resistance wire?) is getting 4.6 volts but the other circuits are getting 12 volts.
Is there a starter relay or voltage regulator? If they were bad would the engine even crank?
Thanks
 

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Bad/No Gas? Put some Dry Gas and or Fill up with good gas.

I also agree with trying to push start it.
 

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Discussion Starter · #12 ·
YJ Won't start

3/4 tank of fresh gas, plenty of gas getting to carb.
I'll try to push start, if this works then what is the problem?
Thanks
 

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if you are seing spark as you release key... then the ignition switch /cranking circuit if at fault

just wire from battery plus to coil plus side.... use alligator clips or an assistant

crank, it should fire up

remove bypass wire

Michel
74 wag
 

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Discussion Starter · #14 ·
Well guys I still don't know what the problem is. I poured fresh gas straight into carb, and nothing. I tried towing it behind my truck to pop the clutch and nothing. Yesterday I changed the coil, distibutor, cap, rotor and wires from my other 89 wrangler and still nothing. I have fuel and spark but it does not want to start.
 

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Well guys I still don't know what the problem is. I poured fresh gas straight into carb, and nothing. I tried towing it behind my truck to pop the clutch and nothing. Yesterday I changed the coil, distibutor, cap, rotor and wires from my other 89 wrangler and still nothing. I have fuel and spark but it does not want to start.
If you have fuel and spark the only other thing that comes to mind is compression. Any recent changes like distributor or timing? I chased a distributor related issue in a chevy once.
Just a thought.
 

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If you have fuel and spark the only other thing that comes to mind is compression. Any recent changes like distributor or timing? I chased a distributor related issue in a chevy once.
Just a thought.

I'm thinking the same thing.
 

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Same thing happened to my lawn tractor, gets spark and fuel, gotta be the timing. Are you getting good spark? It should be blue. Sometimes a weak yellowish spark is not enough to get things burning.
 

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not to familiar with 89's, do you have the brain box mounted on one of the inner fender wells that attaches to the distributor? i had an '84 cj with a carbed 4.2l that lost spark and that was the culprit. if so change that over from your other yj. we've got to be getting closer.

do a quick check of your timing. follow your #1 spark plug wire back to your distributor and mark that posotion on the body of the distributor. now pull the cap and bump the starter until the rotor is pointing at that mark. now pull #1 spark plug to verify the piston is at top dead center. also check your harmonic balancer to see if the TDC mark is near the timing mark (or within spec, maybe 5* BTDC?)

next would be compression check.

sorry for taking so long to get back, i've been gone for a week.
 

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Discussion Starter · #19 ·
YJ Won't Start

Hey Guys,
Thanks for all the replys, but still nothing. I changed the ignition control module before everything else. I check the timing again to see where I'm at. Spark is yellow and maybe kinda weak. I was originally running a Jacobs High Voltage coil, but swapped it to stock to see if that was the problem, still no luck.
Thanks
 

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Hey Guys,
Thanks for all the replys, but still nothing. I changed the ignition control module before everything else. I check the timing again to see where I'm at. Spark is yellow and maybe kinda weak. I was originally running a Jacobs High Voltage coil, but swapped it to stock to see if that was the problem, still no luck.
Thanks

if you went from a jacobs high voltage to a stock coil might the plugs be gapped a bit too much. when i put a high voltage coil on my yj i had to gap the plugs at .065 where stock is .032?

maybe too much gap creating yellow (weak) spark.

how about a quick post of everything done so far so we don't have to reread all posts. and maybe plug gap.
 
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