Crank But No Start

So open it up?

C444E038-72D2-4BF5-B109-2DF5D230BD87.webp
 
I'm sorry. I'm lost here. I see your diagram but don't know how it relates to the coil I have. Which are the + and - terminals on the coil pack?
 
I'm sorry. I'm lost here. I see your diagram but don't know how it relates to the coil I have. Which are the + and - terminals on the coil pack?
Unplug the coil connector. You have three wires. One is battery voltage, remember testing the wiring? Dark green with a light green tracer terminal cavity 2. Put the positive lead on the terminal in the coil that corresponds with cavity 2. Put the negative lead on the terminal that cavity 1 would plug onto. Write that number down. Do it again but this time move the negative lead to the terminal that matches up with cavity 3. Write that number down. Now you have your two primary resistance values. Put the negative lead into each of the 4 coil towers with the positive lead staying on terminal 2. Write those four numbers down. Those are your secondary resistance values. Are they in spec?
 
Ok. Primary resistance is in spec at .6ohms. Secondary resistance does not read at all. Attaching photos so you can check my work.

45FD049F-64C5-4599-B8BC-4BD9F2AA9EA2.webp


2EADC186-71D4-4B9F-BE27-E6B2960E0662.webp
 
You da' man! Thanks again (y) (y) I will get a new coil and report back.
You may have other issues in addition to the coil. Remember number one injector plug and the failed noid light test.
 
Ok new coil - new symptoms still no spark with #1 and oddly enough, after trying to start it, cylinder 1 is smoking - even though I have the plug pulled out. Still have crank, no start, no spark on #1 and only tries to start when I use starting fluid.

03A00A16-1532-42B4-B395-2F72B1EA731A.webp
 
Ok. So here is where I am at. New coil installed. Here is my test.

1) I pulled the fuel pump fuse
2) No spark on #1 with ASD relay in
3) No spark with ASD jumpered
4) Pulled Ignition coil connector and measured voltage in pin #3 with ASD jumpered.

Back to the drawing board.
 
Ok new coil - new symptoms still no spark with #1 and oddly enough, after trying to start it, cylinder 1 is smoking - even though I have the plug pulled out. Still have crank, no start, no spark on #1 and only tries to start when I use starting fluid.

How do you know you have no spark on cylinder number one? The fumes could be from trying to start the engine for how many times? Slow down and explain clearly what you did from the last time we had contact.

Ok. So here is where I am at. New coil installed. Here is my test.

1) I pulled the fuel pump fuse
2) No spark on #1 with ASD relay in
3) No spark with ASD jumpered
4) Pulled Ignition coil connector and measured voltage in pin #3 with ASD jumpered.

Back to the drawing board.


Slow down now. Remove that jumper before you cook your new coil.
 
Last edited:
Sorry. I was trying to go upstream of the coil to find out why I wasn’t getting spark after replacing the coil. Spent a lot of time on 8w-10-16 checking voltage all the way back to fuse 9. Then headed over to 8w-30-7 ending the pcm. As I looked at 8w-30-7 closer I saw some dependency on the camshaft sensor. Closer examination of the wires indicates some insultation remove and potential rubbing. Late night. Will check for continuity tomorrow.

image.webp
 
  • Like
Reactions: Daryl
Sorry. I was trying to go upstream of the coil to find out why I wasn’t getting spark after replacing the coil. Spent a lot of time on 8w-10-16 checking voltage all the way back to fuse 9. Then headed over to 8w-30-7 ending the pcm. As I looked at 8w-30-7 closer I saw some dependency on the camshaft sensor. Closer examination of the wires indicates some insultation remove and potential rubbing. Late night. Will check for continuity tomorrow.
Good job finding that. You definitely have a mess on your hands, 😆. If that’s any indication of what the rest of the wiring looks like, you need to inspect every inch of that wiring in the engine compartment.
 
  • Like
Reactions: Sputter
Finally got this out. It is a mess for sure. Will be pulling all the tape and loom off today and testing every wire. Stay tuned!!

DA33ED6E-3CE8-4615-B6C6-FF7F4CEFE512.webp
 
  • Like
Reactions: Daryl
Finally got this out. It is a mess for sure. Will be pulling all the tape and loom off today and testing every wire. Stay tuned!!
While you’re inspecting & repairing that harness keep a couple things in mind. Has the insulation lost it’s pliability & crack easily? If the answer is yes, it may be a good idea to buy a used harness from Davey’s Jeep or someplace like that. Also, take a good look at the injector plugs/wires & try to determine what’s going on with having what appears to be 4.0L plugs instead of the 2.5L. And lastly, check the injector part numbers to make sure they are correct for your engine.
 
@AgentLJ - Daryl has been awesome and I have learned a lot. Also helped printing out the full wiring section and binding it (UPS Store).

@Daryl - insulation is brittle but the wiring is still pliable. My guess is that someone tried to trim down a 4.0 harness because they couldn’t find one for the 2.4 but I will double check.

Finally got the harness stripped down. Now for continuity testing.

C1FC8E1F-9EF0-409A-A61C-8A8DAA6233E6.webp
 
  • Like
Reactions: Daryl and AgentLJ
Check those injector plugs for signs of replacement pigtails as I found out in Internet land that people install different injectors in these 2.5’s thinking their going to get more power.
 
Last edited: