Will not stay running?

1979 JEEP CJ7
79,678 MILES • 4.3L • 6 CYL • 4WD • MANUAL
Avatar
DANIEL JENNIFER PIERCE
  • MEMBER
  • 4 POSTS
I bought a new 79 cj7. I drove it home a few weeks ago and it did fine. Next day I took it out for a spin, and it shut off on me initially thought ran out of fuel. Have put 7 gallons in it and changed fuel filter. Still not starting it cranks and fires for a second but when you release key it doesn't stay running. Changed ignition module same results.
Images & Video (Click to enlarge)
Attached Media
Attached Media
Attached Media
Feb 17, 2023 at 1:03 PM
Advertisement
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
Thanks for the video and images. Will it stay running if you hold your foot on the throttle slightly? It sounds like either the carburetor has a clogged idle circuit or there is a vacuum leak. I would start by removing the EGR valve and running this test in the video below.

https://youtu.be/DqUCbbKdWf4

If it passes have a helper hold the RPMs up slightly and use this guide to look for vacuum leak when the engine is cold:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please go over these guides and get back to me.
Feb 18, 2023 at 9:15 AM
Avatar
DANIEL JENNIFER PIERCE
  • MEMBER
  • 4 POSTS
I actually messed with it today. I have 0-voltage at resistor when key is in run position. I used a jumper wire from battery to resistor headed to coil and it fires right up. Remove the jumper wire and he shuts down.

Not getting any juice from ignition switch. I've got a new ignition switch coming.
Feb 18, 2023 at 10:04 AM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
Good find on that, please let me know if the switch fixes it.
Feb 19, 2023 at 3:09 AM
Avatar
DANIEL JENNIFER PIERCE
  • MEMBER
  • 4 POSTS
Well, I got to messing around in fuse box and the 30amp fuse for coil was blown so I replaced that, and she fired like a champ last night. But today driving it a little the starter gear is not retracting like it should. It does retract it I clutch and put it in gear. But going down the road every once in a while it sounds like that starter gear is protruding just a bit and occasionally engages with flywheel. Any idea starter or solenoid?
Feb 19, 2023 at 3:56 AM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,256 POSTS
The starter index return spring can be weak or broken, I would remove the starter and see if the bendix gear is hanging outward.
Feb 20, 2023 at 4:30 AM
Avatar
DANIEL JENNIFER PIERCE
  • MEMBER
  • 4 POSTS
Is that spring a part that can be purchased and replaced?
Feb 20, 2023 at 5:23 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.