• 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.

Sudden Stall

Highlights Only
Sudden Stall
That spark plug looks a bit shiny, like it is wet with fuel indicating a rich condition, where you should be getting a "Check engine light". A good location to check fuel pressure would be close to the entry point of the throttle body or multiport manifold providing what f.i. system you have. You might want to find out what system you have to determine how much pressure is required.
 
Its a Rochester Products TBI. I have had some trouble finding any SPEC information to determine what fuel pressure should be. These were made for GM. Wouldn't the fuel pressure be determined by the combustion requirements of the motor, not the delivery system? In other words, would the pressure vary based on TBI or carb? I usually can smell fuel when it is operating. It got must better when I replaced the O2 sensor, but every now and again, I can still smell it. I just figured that was a product of the TBI.
 
So its probably a Rochester 220 tbi. You could have a Howell kit. If you bring up https://howellefi.com/product-category/jeep-tbi-products/, You might find a similar setup to yours. This will allow you to down load the instructions that could help get you going. A recommended fuel pressure is around 10-14 psi I believe, I keep mine around 10. There is a flathead screw slot located where the pressure and return fuel lines go into the rear of the tbi underneath. Adjusting the screw clockwise will cut the pressure down. I have a tee fitting mounted on the pressure side and screw in a pressure gauge to check. Sometimes the 1/4" oem fuel return line can clog up and will increase the pressure. Installing a 5/16" fuel return line is a better bet. There are a few other outfits that built a tbi kit for the CJ also, even a few guys built their own. I have a very rich choke that mine came set up with but leans out as the engine warms up.
 
Last edited:
Check your coil. My Jeep started missing then suddenly died just yesterday. I put a timing light on and had no spark to any of the cylinders. Swapped out the ignition module with a spare, no luck. Swapped out the e-core coil with a spare and Wa La!


Sent from my iPhone using Tapatalk
 
apache5g said:
Am I able to replace just the coil on an HEI?
Click to expand...

Yes you can but don't just replace it without testing it first by testing the resistance across the terminals. I'm not sure what the resistance values should be but you should be able to google it or hopefully somebody on this forum who knows will pipe in. Might not be your problem but something to rule out.
 
thundley57 said:
Yes you can but don't just replace it without testing it first by testing the resistance across the terminals. I'm not sure what the resistance values should be but you should be able to google it or hopefully somebody on this forum who knows will pipe in. Might not be your problem but something to rule out.
Click to expand...

Somewhere around 1.13 to 1.23 ohms across the plus and minus terminals.
 
So the coil checked out as well as the other ignition components as best I can tell. I was able to find the installation manual for the TBI kit, and it included some trouble shooting checks. While checking the fuel spray I got a pretty substantial flare up on top of the TBI. I am guessing I need to go along the route of fuel pressure, clogged return line etc...Any suggestions would be appreciated. Here is a link to the video.

https://youtu.be/zbfUh1Fhr7Q
 
Backfires like that can be the result of the timing being too advanced. In the video it kind of acts like the timing may be off (advanced too much). There is a specific procedure for setting base timing on a TBI system. It basically involves disconnecting a wire in the harness to disable ESC, allowing you to set base timing to 0 (zero). If your distributor has moved to where it's at 10-12 degrees base, as soon as the engine starts running ESC will add another 15-18 degrees to that which can cause big problems at idle.
 
Thanks for the response. Do you have any idea how the timing could have advanced so far after only changing the oil, and putting the wheels back on it? A buddy suggested that when I did the oil flush, perhaps some debris or gunk lodged one of the valves open. He suggested a compression test on all the valves. Does that sound viable as well?
 
Thanks for that video. A cylinder compression test is a good idea to help you know just what is going on inside your engine. Since you know you have spark, and if you have not messed with it, there must be a fuel issue. Although in the video, there is just too much of it. You might want to wipe the spark plugs clean when it floods out like that. When you were trying to start it I could see both injectors working.
 
PistolDave said:
Backfires like that can be the result of the timing being too advanced. In the video it kind of acts like the timing may be off (advanced too much). There is a specific procedure for setting base timing on a TBI system. It basically involves disconnecting a wire in the harness to disable ESC, allowing you to set base timing to 0 (zero). If your distributor has moved to where it's at 10-12 degrees base, as soon as the engine starts running ESC will add another 15-18 degrees to that which can cause big problems at idle.
Click to expand...

:agree:
 
Hello everyone. I was able to do some troubleshooting with the timing. The link is a video of that result. It sounds like the timing is about as good as I am going to get it without it being able to run and verify with a light. In this video, the motor acts like it wants to run, and then when I release the key from the run position it dies. While the key is held in the run position it feels like it wants to stay running. Thanks in advance for any additional guidance.

https://youtu.be/pFBUBx4vkwc
 
I would say that the secondary ignition system is not coming on. That can happen when the red with white tracer wire and the light blue wire are reversed, but you did not say that you were working on that.
 
First-Put 5gal of gas into the tank.
Now-Run a jumper wire from the POS(+) post on the battery to the POS(+) post on the coil.
Will it keep running now?:confused:
IF, it does. You have an issue in the ign switch itself, or the circuit.
Pull the wire to 'kill' the engine. Don't run it more than 5 minutes like this, as it's hard on the coil.
LG
 
I ran a jumper wire as suggested by LG. The Jeep ran on its own. I replaced the ignition switch. Same problem. I used the jumper wire with the new switch and it ran on its own as well. I traced the wire from the HEI BATT terminal and it looks like all the connections are good. I am wondering if this is just a failure of the computer. Additionally, I checked the the volt reading at the distributor with the ignition in the "start" position. There was no reading until the key turned into the "run" position. I got 11.5-12.4 volts when trying to start. Shouldn't I have current in the "start" position. I am getting an ohms reading as suggested in a previous post, but my understanding is that ohms is a measure of resistance, and not of current.
 
When the ignition switch is in the on position, it sends power to the coil from the red w/white tracer wire from the switch. Since it does not run in the on position without a hot wire to the coil, you might want to trace down that wire. The ignition switch gets its power from the hot side of the starter relay which also powers the light switch and horn, do they work?
 
The head lights/dash lights/turn signals/brake lights work. The horn is a button that was added to the bottom of the dash panel near the steering column. It was part of that additional stand alone fuse box that powered the stereo/CB/and LED lights in the bumper. (That also lost power when this gremlin showed up) I disconnected all the components from that stand alone fuse box as a way to narrow down the problem.
 
mtnwhlr said:
I don't see how what you did could have anything to do with it. It takes two thing to make a motor run, spark and gas. Take the air cleaner off and see if it is spraying gas when you hit the gas and make sure your plugs are firing.
Click to expand...

Might require some air, just saying....

slomo
 
You must log in or register to reply here.

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
$0.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  0.0%
Contribute
Back
Top Bottom