No spark on two wires.

Tiny
JR86TEK
  • MEMBER
  • 1993 JEEP GRAND CHEROKEE
  • V8
  • 4WD
  • AUTOMATIC
  • 189,000 MILES
No spark is getting to cylinder 3 and 5.
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have the same problem?
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No
Thursday, July 7th, 2011 AT 2:18 AM

17 Replies

Tiny
CJ MEDEVAC
  • EXPERT
How do we know there is no spark on those 2. Test you performed?

Is your check engine light on?

The Medic
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Thursday, July 7th, 2011 AT 4:11 AM
Tiny
JR86TEK
  • MEMBER
The check engine light is not on. I checked for continuity and spark tested all the ignition wires and those two are the only ones that don't have any spark. I also swapped two good working ignition wires for the the suspect bad wires and got no spark.
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Thursday, July 7th, 2011 AT 4:50 AM
Tiny
CJ MEDEVAC
  • EXPERT
What have you done or replaced?

You say that you actually "saw"/ "watched" spark (like lightening) "Jump" from a spark plug, attached to the ends of 6 of your 8 wires. And 2 would not jump a spark to ground. Even swapping them, with a "proven, wire and plug"

You must understand why I have to get really specific, and even so, if you are sorta lost, we all have been there.I just wanna help you, correct info, is a plus!

The Medic
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Thursday, July 7th, 2011 AT 6:01 AM
Tiny
JR86TEK
  • MEMBER
The engine is rebuilt and since the rebuilt I can't get it to run well. The following are new parts:

Distributor with camshaft sensor
cap and rotor
crankshaft sensor
spark plugs and wires
ignition coil

I spark tested the ignition wires with a calibrated spark plug tester and unless the spark was really weak on 3 and 5 I didn't see any spark.
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Thursday, July 7th, 2011 AT 10:58 PM
Tiny
JR86TEK
  • MEMBER
More info:

When I spark tested the ignition wires I did noticed that some of the wires had weak sparks while others had strong sparks.
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Thursday, July 7th, 2011 AT 11:02 PM
Tiny
CJ MEDEVAC
  • EXPERT
Wires old?

Advance Auto and Autozone offer lifetime warranty's.I like 'em too!

Many times, that has helped me, over the years!

Nearly every replaceable, offered part, I have on my CJ 5 (Mr. Jeep) and quite a few on "Willy", my '46 Jeep. Both have those wonderful warranty's!

I usually just buy oil change stuff anymore, I'm covered for the major stuff!

For Real, My Radiator, Headers, Fuel pumps (3--2 are spares), Drum brake shoes (front and rear, spare set!), Distributor, ignition Module, 4 "U" Joints, starter, alternator, master cylinder, tie rod ends, water pump, thermostat housing, and Mr. Harmonic Balancer are covered.I may have left something out!

When one of these needs replacement.I need no money, sometimes, I get some back.I take in my receipt book. There is no doubt I bought it there, no matter if they can find it on the computer or not! There is really no need to research their computer. Works state to state, so far!

This is also my MPG and maintenance book!

The favorite one, they really like, is from Autozone. In 1989, I got my alternator (the 1st of many) and I started my book then!

SO WHAT ARE YOU WAITIN' ON?

IF THE WIRES HAVE SEEN BETTER DAYS, GET NEW ONES. THEN LET ME KNOW THE DEAL, WE WILL GO FROM THERE!

The Medic
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Friday, July 8th, 2011 AT 12:58 AM
Tiny
JR86TEK
  • MEMBER
Wires have no more than 50 miles on them.
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Friday, July 8th, 2011 AT 6:41 PM
Tiny
CJ MEDEVAC
  • EXPERT
Roger!

Let snatch the distributor cap

Have someone turn it over, while you observe the rotor button, or rotor button removed, and observe the rotor shaft for wobble. Especially look for a bounce or jump in the shaft. We're looking for something wrong with the distributor drive gear on the cam.

I'm sorta eliminating the distributor trigger wheel, and pick-up, cause you have a new one.I'd say it's unlikely that 2 distributors would have exactly the same problem.

The Medic
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Friday, July 8th, 2011 AT 9:31 PM
Tiny
ASEMASTER6371
  • EXPERT
Did anyone check the coil? You can use a spark tester and load it up and see if it breaks down under load.

Roy
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Saturday, July 9th, 2011 AT 1:04 AM
Tiny
JR86TEK
  • MEMBER
Cranked the engine with distributor cap off and everything seemed normal. I had AutoZone test my coil and they said it was toast, so I got a new one. The new coil was tested good at AutoZone. Last night I installed the coil and cranked the engine and got spark from the coil, but no spark from the distributor. I decided to call it a day.

This morning I cranked the engine and got no spark from the coil. I checked for power going to the coil and got twelve plus volts. So, now I have power to coil but no spark from it.
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+1
Sunday, July 10th, 2011 AT 6:59 PM
Tiny
CJ MEDEVAC
  • EXPERT
See if this helps

Coil is Near bottom on right

Let me know if this is hard to read.I will suggest another Route, to get it to you, without you posting your address in "OPEN FORUM", for the world to see

The Medic
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Sunday, July 10th, 2011 AT 7:40 PM
Tiny
JR86TEK
  • MEMBER
I can read it, whats the plan?
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Sunday, July 10th, 2011 AT 8:16 PM
Tiny
CJ MEDEVAC
  • EXPERT
I send you a message here

Look at Home Page

click on your name

then look left you should see messages

Probably see it better on Email

Here goes!

The Medic
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Sunday, July 10th, 2011 AT 8:36 PM
Tiny
CARADIODOC
  • EXPERT
Here's a few things to consider. If you replaced the flex plate, you might have the wrong one. There are four sets of cutouts that are detected by the crankshaft position sensor. Various engines use different numbers of cutouts and configurations.

When you installed the new crankshaft position sensor, did you use a spacer on the end to set the air gap? That gap is critical for proper operation. New ones from the dealer use a thick paper spacer stuck to the end. It slides off the first time the engine is started. Many aftermarket sensors use a thin plastic rib molded to the end. It partially wears away when in operation. To reinstall a used one like that you are to cut off the remaining part of that rib and use a paper spacer.
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Monday, July 11th, 2011 AT 7:10 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi:
These guys have you on the right track. I was wondering if you have resolved the problem. The crank sensor was my first guess after reading your posts. I see you did replace it. Did anything change with the new one? Have you checked the coil for a good solid ground? Have you checked its power supply wire to make sure it isn't causing problems for you? Finally, have you checked the wiring harness pins to the PCM to make sure none are pushed in and making a weak or no connection? Based on what I read, I think either you are dealing with a faulty crank sensor or a weak ground.

Let us know. We'll all receive your update and try to continue helping.
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Friday, July 15th, 2011 AT 3:31 AM
Tiny
JR86TEK
  • MEMBER
Good news! I traced the problem to a destroyed crank sensor. Looks like the crank sensor got badly hit and bent when I was dropping the engine in, oops! I got truck running but its not running smooth, it probably needs a little distributor tweaking, but for now all is well.
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Sunday, July 17th, 2011 AT 2:43 AM
Tiny
CJ MEDEVAC
  • EXPERT
I WAS GONNA SAY THAT NEXT!

YOU MUST LEARN TO ALWAYS BLAME YOUR EVIL BUDDY FOR SUCH THINGS.

THIS KEEPS OUR 1ST IMPRESSION OF YOU INTACT!

I'M GONNA PRETEND WE DID NOT SEE YOU LAST POSTING. TRY IT AGAIN!

THE MEDIC
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Sunday, July 17th, 2011 AT 6:18 PM

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