• Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

No Spark or Fuel During Engine Crank

No Spark or Fuel During Engine Crank
Just for clarification...you've checked all spark plugs and NONE of them light up when grounded and cranking? Just trying to confirm in my own pea brain that you aren't getting spark. I feel like we are all missing something here. Do we know that the coil wire is good?


Sent from my iPhone using Tapatalk
 
Just for clarification...you've checked all spark plugs and NONE of them light up when grounded and cranking? Just trying to confirm in my own pea brain that you aren't getting spark. I feel like we are all missing something here. Do we know that the coil wire is good?


Sent from my iPhone using Tapatalk

Using a inductive pickup timing light, no spark at any cylinders or the coil wire which was new from MSD a couple of months prior to the failure. Trust me, I'm pretty sure I'm missing something. I know this thing is going to probably turn out to be something really simple. Just hope I don't have to pay a mechanic hundreds of dollars to find it for me!
 
You have no spark from the coil.
Try this, test ohms between D1 and – battery post. Disconnect the 4 wire plug at the ignition module and test the distributor side of the plug. The plug will be stamped D1 to D4.

Also test ohms between D2 and D3

Before disconnecting the 4 wire plug, remove the coil wire and hold it close to the block, turn key on (not start). Now disconnect the 4 wire plug, does it spark at the coil wire? Reconnect the coil plug, turn the key off, and do the ohms test above.

Post your findings.
 
Last edited:
You have no spark from the coil.
Try this, test ohms between D1 and – battery post. Disconnect the 4 wire plug at the ignition module and test the distributor side of the plug. The plug will be stamped D1 to D4.

Also test ohms between D2 and D3

Before disconnecting the 4 wire plug, remove the coil wire and hold it close to the block, turn key on (not start). Now disconnect the 4 wire plug, does it spark at the coil wire? Reconnect the coil plug, turn the key off, and do the ohms test above.

Post your findings.

Will do Posi. Will report back tomorrow with findings. Not sure where you're headed with this but obviously you do! :)
 
If you still have your old coil-Try it. ;)
LG
 
* I installed my brand new spare e-core coil (no change). Both coils tested about the same with my ohm meter with about 2 ohms on the primary and 8000 ohms on the secondary
...
 
Has the fuel pump been checked for correct psi ? Some FI setups have it, if the FP acts up and the injector doesn't 'see' the correct psi, it shuts the spark down and the injector won't work.
LG
 
Has the fuel pump been checked for correct psi ? Some FI setups have it, if the FP acts up and the injector doesn't 'see' the correct psi, it shuts the spark down and the injector won't work.
LG

Yes. I installed an in-line fuel gauge when I installed the Howell conversion kit which pumps right up to the required 12 psi when the key is turned to the run position. It just won't come on while cranking as it is supposed to but I'm confident that will be cured if and when I ever figure this ignition problem out. Thanks!
 
Has the fuel pump been checked for correct psi ? Some FI setups have it, if the FP acts up and the injector doesn't 'see' the correct psi, it shuts the spark down and the injector won't work.
LG
Not in this case Lumpy, The oxy sensor will read a lean condition and the computer will read a fuel pump low voltage. I do think the computer is not getting a tach signal though.
 
THX T'head:chug:-I'm a 'carb-guy' and FI is pretty much 'Greek' for me. :laugh:
If the fuel pump ain't run'n at all-Run a 'jumper' wire from the battery POS(+)to the pump. Now the pump should run till cut-off PSI is built. Try to start. Remove wire if 'no-joy'.
Good luck:notworthy:
LG
 
This problem reminds me of a very similar thing I ran into about 3-4 years after I bought mine new. Spent about 2 weeks going over the electrical system and pulling out most of my hair and replacing several electrical parts. Ended up being a ground wire on the engine
 
Looking back to post #70, I see there is a concern for the distributor pick up coil. A way to check that would be to unplug the distributor plug and get 400-800 ohms off the violet and orange wires from the distributor. Also another way to check the ignition coil is to disconnect existing wires to it and get around 1.35 ohms from the two terminals. The distributor should not get any resistance to the battery ground either as the black wire on the distributor harness grounds the ignition control module. If you ever have to purchase another icm, I would suggest the Echlin brand from N.A.P.A. although they cost a lot more. I was wondering if hot wiring would get the engine to fire since this issue is pretty extensive. For my issues, I have got more than my moneys worth from the factory service manual.
Edit: Make sure that there is no ground connections when checking the pick up coil.
 
Last edited:
You have no spark from the coil.
Try this, test ohms between D1 and – battery post. Disconnect the 4 wire plug at the ignition module and test the distributor side of the plug. The plug will be stamped D1 to D4.

Also test ohms between D2 and D3

Before disconnecting the 4 wire plug, remove the coil wire and hold it close to the block, turn key on (not start). Now disconnect the 4 wire plug, does it spark at the coil wire? Reconnect the coil plug, turn the key off, and do the ohms test above.

Post your findings.

Posi, unfortunately there are no stamps on the 4 wire plug of my ignition module. Searched high and low but nothing. Is there anyway you could tell me which color wire associates with which label? I did the spark test placing the distributor side of the coil wire a fraction of an inch away from the engine block and with the key on, disconnected the 4 wire connector from the icm and observed no spark.
 
Looking back to post #70, I see there is a concern for the distributor pick up coil. A way to check that would be to unplug the distributor plug and get 400-800 ohms off the violet and orange wires from the distributor. Also another way to check the ignition coil is to disconnect existing wires to it and get around 1.35 ohms from the two terminals. The distributor should not get any resistance to the battery ground either as the black wire on the distributor harness grounds the ignition control module. If you ever have to purchase another icm, I would suggest the Echlin brand from N.A.P.A. although they cost a lot more. I was wondering if hot wiring would get the engine to fire since this issue is pretty extensive. For my issues, I have got more than my moneys worth from the factory service manual.
Edit: Make sure that there is no ground connections when checking the pick up coil.

Thanks Torxhead. I will test the distributor plug resistance tomorrow. I checked the resistance of the coil the other night and was just over 1 ohm on both the installed and my backup coil. You mentioned that the distributor should not get any resistance to the battery ground either, can you tell me how to test this?
 
This problem reminds me of a very similar thing I ran into about 3-4 years after I bought mine new. Spent about 2 weeks going over the electrical system and pulling out most of my hair and replacing several electrical parts. Ended up being a ground wire on the engine

Thanks Belizean, will thoroughly look over my grounds as well. Was your failure similar to mine, engine running normally and then a suddenly nothing as if the key had been turned off?
 
Posi, unfortunately there are no stamps on the 4 wire plug of my ignition module. Searched high and low but nothing. Is there anyway you could tell me which color wire associates with which label? I did the spark test placing the distributor side of the coil wire a fraction of an inch away from the engine block and with the key on, disconnected the 4 wire connector from the icm and observed no spark.
D1 - Black
D2 - Violet
D3 - Orange
D4 - Green
 
Thanks Belizean, will thoroughly look over my grounds as well. Was your failure similar to mine, engine running normally and then a suddenly nothing as if the key had been turned off?

YES LIKE THE KEY HAD BEEN TURNED OFF. Coasted to a stop. It was just dead. Waited for my buddy to get off from work and used a pull strap to get it to his house. He was and is a master mechanic and we spent many an evening going through that thing. I already had the shop manual and wore it out. Finally started changing a few parts, the box under the coolant tank, pickup in distributor and swapped out some of the relays. NOTHING. We just weren't getting anywhere. Finally made the decision that we needed a fresh set of eyes. That was the only time it went back to the dealer. They even had difficulty finding the problem. Called it fusible link at the time. It was loose. That was a learning experience for the both of us but especially for my buddy. He was dealing with something like that just a couple of months ago and dealing with what he thought was a intermittent automatic Transmission problems and turned out to be a ground to ECM.
 
Thanks Torxhead. I will test the distributor plug resistance tomorrow. I checked the resistance of the coil the other night and was just over 1 ohm on both the installed and my backup coil. You mentioned that the distributor should not get any resistance to the battery ground either, can you tell me how to test this?

Using the ohm meter, there should be no reading at all between the ground and either the orange or violet wire. The black wire in the distributor harness is the ground wire to the icm. So when the harness is plugged in, there is a connection between that black wire and the ground. If that black wire is not grounded correctly, it can destroy the icm.
 
To verify the connection on the icm:
lt. blue wire-from ign. pin s, hot during start position
red w/tracer wire-from ign. pin 11, hot during on position
dk. green wire-to ign. coil negative
orange wire-to pickup coil in distributor
black wire-to ground, I think the best place for this wire is to run it direct to the battery negative.

Edit: The wire colors should match up anyway.
 
Last edited:
Using the ohm meter, there should be no reading at all between the ground and either the orange or violet wire. The black wire in the distributor harness is the ground wire to the icm. So when the harness is plugged in, there is a connection between that black wire and the ground. If that black wire is not grounded correctly, it can destroy the icm.

Torxhead, sorry for the stupid question but when it comes to electrical I consider myself a baby. So I disconnect the distributor connector and test the resistance between the violet and orange wires (on the distributor side) to battery ground, is this correct? If I have this right in my mind I'm testing how well the distributor is grounded via the hold down clamp right?

So many thanks to the rest of you for your testing procedures and advice! Posi thanks for the color codes. I'm going to perform all of these tests today and will report back tonight. It is less frustrating for me when I have something to do to narrow this problem down instead of just staring under the hood thinking "where do I go now"! Thanks to all of you!
 

Similar threads

  • Question<br> <font color=black> Reply's are voted<br> on for best answer</font> Question
    Reply's are voted
    on for best answer
Replies
5
Views
60
  • Question<br> <font color=black> Reply's are voted<br> on for best answer</font> Question
    Reply's are voted
    on for best answer
Replies
17
Views
184
  • Question<br> <font color=black> Reply's are voted<br> on for best answer</font> Question
    Reply's are voted
    on for best answer
Replies
3
Views
179
  • Question<br> <font color=black> Reply's are voted<br> on for best answer</font> Question
    Reply's are voted
    on for best answer
Replies
5
Views
326
  • Question<br> <font color=black> Reply's are voted<br> on for best answer</font> Question
    Reply's are voted
    on for best answer
Replies
7
Views
139

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$25.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  12.5%
Back
Top Bottom