× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

1999 Jeep WJ 4.0, Crank but no Start

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
29 Apr 2019 19:33 #29125 by Rocketman
1999 Jeep WJ 4.0, Crank but no Start was created by Rocketman
I need some help. 1999 Jeep WJ 4.0. To give a little history, The Car started dying may run down the road a few miles then die. It would start right back up but would die again and again. After searching the web most folks claimed it was the PCM or Crankshaft sensor. Well I started throwing parts at it with a PCM after a NEW PCM the car did the same thing. Next i order a Crankshaft sensor and was looking for the cable of the crankshaft sensor plug and I cut away some tape on the wire harness and cut 3 wires into, not the 3 to the crankshaft sensor., I repaired those wires and unplug the crankshaft sensor Now the car won't run. It turns over but acts like its out of time as it turns over slow and almost back-fires.It sounds just like the Jeep ScannerDanner was working on in one of his video's where he was using a test light to show RPMs on his scope. Then i found ScannerDanner's Video's and I got me a Mutl-meter, I know I should of done this first. Then after I probe the 3 wire plug to the crankshaft sensor and Found Ref 5 Volt. center Ground, and the outside pin show .003 Volts plugged in. When i un-plug the sensor the 3rd pin would go to 5 volts. So i order another sensor. Put it in and still get the same reading. It has a New Batt. Oh and a New Coil Pack and Spark plugs. Where should i look next?

Please Log in or Create an account to join the conversation.

More
29 Apr 2019 23:19 #29131 by jreardon
Replied by jreardon on topic 1999 Jeep WJ 4.0, Crank but no Start
Any codes to mention?

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
30 Apr 2019 10:59 #29139 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
No Codes.

Please Log in or Create an account to join the conversation.

More
30 Apr 2019 19:41 #29147 by overdrive138
Replied by overdrive138 on topic 1999 Jeep WJ 4.0, Crank but no Start
I would check the harness that runs behind the valve cover for cut wires from the valve cover bolts. Also chk the asd relay make sure its good . chk all 3 connectors to pcm unplug clean dielectric grease and plug it back in, these are known to have bad or loose connections etc also move the harness around see if that fixes it first. And chk your iac valve known to get stuck leak etc.

Please Log in or Create an account to join the conversation.

More
30 Apr 2019 20:03 #29149 by jreardon
Replied by jreardon on topic 1999 Jeep WJ 4.0, Crank but no Start
Backfiring suggests ignition spark occurring with intake valve open so maybe it's a jumped timing belt. Can you do a clear flood mode crank and listen for odd sounding cylinders?

Do you have spark? Can you smell fuel? Is injection pulse present?

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
03 May 2019 11:19 #29244 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
I'm repairing two wires that was patched in the harness then putting the harness back in place and doing all my checks again. Will post as soon as i'm done.

Please Log in or Create an account to join the conversation.

  • Noah
  • Noah's Avatar
  • Offline
  • Moderator
  • Moderator
  • Massachusetts, USA
More
04 May 2019 13:19 - 04 May 2019 13:21 #29288 by Noah
Replied by Noah on topic 1999 Jeep WJ 4.0, Crank but no Start
99 was a one year fit for many parts on those Grand Cherokee engines. I have personally been bit by this and have seen other very good techs go down the rabbit hole (so far as to pull the timing cover to check the chain) after changing the ignition coil. It must be for a 99 model year. The other ones will plug in, but the connector is upside down. It fires the plugs in the wrong order and you get the back fire, no start.
I'm not saying that's definitely what's going on with yours, but it's worth a look.

"Learn, apply, repeat."
Last edit: 04 May 2019 13:21 by Noah.

Please Log in or Create an account to join the conversation.

More
06 May 2019 23:08 #29356 by kevinedward1234
Replied by kevinedward1234 on topic 1999 Jeep WJ 4.0, Crank but no Start
Does this engine have a coil pack, coil over plug. If so, look at the cam sensor for damage or missing magnet!

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
08 May 2019 16:49 #29412 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
Its a Coil-over-pack. today my new Coil-over-pack came in and i installed it. It only backfired. Update on Crankshaft sensor. Key-on. I have my 5volts ref, I back probe the signal wire and hand cranked the crankshaft watching the Meter. I have my on and off 5 Volts. Now, Should or can i do some checks on Cam sensor?. I know i have my 5 volts This was a running car when i parked it The reason i stated working on it it started dying driving down the road. I broke the elect connect to the coil-over-pack Trying to get room on the wiring harness was why i changed it out. After putting all the parts on. It now only backfires. I hope i've given all the info i can. But if more is needed Please ask.

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
19 May 2019 15:38 - 19 May 2019 15:41 #29821 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
I'm starting to feel like Noah on the Coil over plug. Even tho I've replaced to 2 times and still does the same thing. I don't have the old one its in the trach. Does anyone have a diagram of the wiring to the Coil over plug. ?? If so can you send one to me at This email address is being protected from spambots. You need JavaScript enabled to view it. thanks
Last edit: 19 May 2019 15:41 by Rocketman.

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
21 May 2019 12:15 #29885 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
Good News the Jeep started. I found on youtube a guy with the same problem, he had a new Coil over plug pack and it was wired backward. I tried two new coil packs and both where wrong. So watching this guys youtube he reversed the elect pins and it ran, I did the same thing. Man you know how long I've been trying to fix this thing and all the time it was the parts i was buying. It now does show #4 plug not firing i have a new plug going to hope that's all it is.

Please Log in or Create an account to join the conversation.

More
23 May 2019 18:44 #30006 by Desmond6004
Replied by Desmond6004 on topic 1999 Jeep WJ 4.0, Crank but no Start

Rocketman wrote: Good News the Jeep started. I found on youtube a guy with the same problem, he had a new Coil over plug pack and it was wired backward. I tried two new coil packs and both where wrong. So watching this guys youtube he reversed the elect pins and it ran, I did the same thing. Man you know how long I've been trying to fix this thing and all the time it was the parts i was buying. It now does show #4 plug not firing i have a new plug going to hope that's all it is.

Those are the worst type of faults to fix - when brand new parts are causing the problem you starts doubting your skills.

Getting involved in discussions because I have a lot to learn still.
The following user(s) said Thank You: Rocketman

Please Log in or Create an account to join the conversation.

  • Rocketman
  • Topic Author
  • Offline
  • New Member
  • New Member
More
27 May 2019 07:24 #30149 by Rocketman
Replied by Rocketman on topic 1999 Jeep WJ 4.0, Crank but no Start
Plug fixed the miss, Running Great. Thanks to everyone who responded to my post.

Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to add attachements.
  • Not Allowed: to edit your message.
Time to create page: 0.693 seconds