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Topic Review (Newest First)
10-26-2011 08:43 AM
drplg2549 Just thought I would update on the post.
I replaced the ICM last night. Out of the garage it was spitting and sputtering a little and as I drove down the street, was pretty weak. I tried getting on it a little to see how it would respond, and found a dead spot. I let off, turned around as to not get too far from the garage, and tried again.. same result.. pretty weak and a dead spot.

I brought it back home and let it sit and idle for about a half hour. It idled fine and did not die on me.. I tried shutting off and starting up again a few times and no issues. I even pushed down the gas pedal once or twice prior to starting to see if it would flood (which it always had done even with the slightest bump of the pedal). It started with no issue.

I then took it for another drive and this time, no dead spot but still a little weaker than it was originally.
Not sure why it is still a little weak, but if it doesnt shut down on me, and now that the dead spot seems to have gone (for now), I am content.

We will see tonight and over the next few days how it does overall.

Thanks for all the help, and Kahuner.. I will certainly take note of your advice.. just hoping to not have to stick too much more into her at this time!
10-25-2011 08:05 AM
kik
Quote:
Originally Posted by Kahuner View Post
I'm also new to the YJ Forum and YJ ownership. I have an '89 4.2L 5 spd manual.

Your '90 and my '89 suffer from lack-luster engineering when it comes to ignition and the fuel system.

I walked the halls of Jeep/Truck Engineering for 20 years as a Supplier Rep. and I specifically remember how desperate Chrysler was in '84, '85., '87 when the YJ was being developed.

My point being; the carb and the ignition should be upgraded to a Motorcraft 2100/2150 carb and a Ford F150 coil and dist. cap & wires. Not saying you can't make the stock (carb & ign) systems work but the stock configuration on a good day will never be capable of performing like one that has been upgraded. For the most part, these are the 2 biggest reasons why a YJ got such a bad rap. Jeep responded by going to EFI in '91 on the 4.0L engine.

I spent $300 on the Motorcraft carb and about $100 on the ignition. $400 gets you 98% of the way (cost wise) out of a design flaw that could be a potentially more expensive road; by trying to fix a stock system.

Hope this info helps you make good choices.

Kahuner
Great suggestion.
10-24-2011 08:07 PM
Kahuner I'm also new to the YJ Forum and YJ ownership. I have an '89 4.2L 5 spd manual.

Your '90 and my '89 suffer from lack-luster engineering when it comes to ignition and the fuel system.

I walked the halls of Jeep/Truck Engineering for 20 years as a Supplier Rep. and I specifically remember how desperate Chrysler was in '84, '85., '87 when the YJ was being developed.

My point being; the carb and the ignition should be upgraded to a Motorcraft 2100/2150 carb and a Ford F150 coil and dist. cap & wires. Not saying you can't make the stock (carb & ign) systems work but the stock configuration on a good day will never be capable of performing like one that has been upgraded. For the most part, these are the 2 biggest reasons why a YJ got such a bad rap. Jeep responded by going to EFI in '91 on the 4.0L engine.

I spent $300 on the Motorcraft carb and about $100 on the ignition. $400 gets you 98% of the way (cost wise) out of a design flaw that could be a potentially more expensive road; by trying to fix a stock system.

Hope this info helps you make good choices.

Kahuner
10-24-2011 03:10 PM
drplg2549 I have an ICM ordered and will replace tomorrow. Hope that does the trick!
I have no knowledge of the Nutter concept.. but can research it-

Prior to this stopping at will situation, it ran idled and accelerated without issue, just was easy to flood but could easily counter by foot to floor technique.

Since the intermittent stopping issue, all these things have come about, so hopefully carb is alright-
I will certainly touch base and let you know how the ICM works, and ask if I need more assistance!

This has been very helpful, and I thank you!
10-24-2011 02:46 PM
kik
Quote:
Originally Posted by drplg2549 View Post
kik and barjeep-
Thanks for the help. It is greatly appreciated!
I will do just that.
Can you tell me.. will this take care of the issue i am having with it dogging out when i try to get up and go?
or with the fact that it has the history of flooding with even the slightest touch of the accelerator when going to start it?

I am just trying to gauge whether or not I will need this AND a carb.. or just this-

Thanks again!
Replace the ICM and go from there. Chances are your carb is due for a rebuild or replacement (there are a ton of things you can do regarding the carb; search nutter bypass). I went with a rebuild for my 89, but I knew the tech who did it and it runs great. Maybe you won't have to do anything. When ICM's start to go bad they can be intermittent which causes the loss of spark, which causes a flooding situation. Another symptom is "dogging" when you try to get up and go. A problem with starting would most likely be the auto choke with these carbs. If you still have that situation let us know so we can guide you through that.
10-24-2011 02:10 PM
drplg2549 kik and barjeep-
Thanks for the help. It is greatly appreciated!
I will do just that.
Can you tell me.. will this take care of the issue i am having with it dogging out when i try to get up and go?
or with the fact that it has the history of flooding with even the slightest touch of the accelerator when going to start it?

I am just trying to gauge whether or not I will need this AND a carb.. or just this-

Thanks again!
10-24-2011 01:47 PM
kik
Quote:
Originally Posted by drplg2549 View Post
I thought I have heard that before... Is this implying there is loss of spark still and that the pickup coil replacement might not have been the answer to the original issue?.

I will check the price on them.. if not too expensive replace it.
I appreciate the help on the location!!

Is there any way to test the ICM, that you know of?

Thanks so much!
barjeep is correct. You have the exact symptoms of a bad Ignition Control Module. You can get one for about 60-70$. There is no real world test for them. It just has to be replaced. If you don't you're not going anywhere. Directly under the washer and/or coolant expansion tank. I believe 3 10mm bolts. Plug and play. Easy. Your coil was probably due for replacement anyway. I changed both in my 89 when I did it to not have a future problem.
10-24-2011 01:29 PM
drplg2549 I thought I have heard that before... Is this implying there is loss of spark still and that the pickup coil replacement might not have been the answer to the original issue?.

I will check the price on them.. if not too expensive replace it.
I appreciate the help on the location!!

Is there any way to test the ICM, that you know of?

Thanks so much!
10-24-2011 01:02 PM
barjeep i would replace the ignition module mine did the exact same thing. mine is also a 90. module is under the windshield washer reservoir
10-24-2011 09:29 AM
drplg2549 Sorry.. It is my understanding that when it floods, by pushing pedal to floor will open it up to clear the flood.. and it does just that, not flood it more-so.
I think you mght be right that it needs to be rebuilt or replaced, just wondering if there might be another issue that I would want to investigate prior to spending 3-400$ on a new carb..?

Thanks for the reply
10-24-2011 09:03 AM
draarong2004 my best guess is the carburator....either needs to be cleaned or rebuilt, more than likely rebuilt, or replaced alltogether..could be a bad fuel filter too, if its flooding, holding the gas pedal down isn't helping, its only going to flood it more, sounds to me more like its not getting enough fuel if its dead from idling for too long.....

i'd replace fuel filter first, then have the carb looked at.
10-24-2011 08:47 AM
drplg2549
New YJ Owner with possible fuel or spark issue

New to this forum and forums in general. Hoping to find a lending hand.
Have a 90 YJ with a glitch.
I bought this truck as a plow vehicle to keep my home/business clear of the snow once it starts falling.
It is a 4.2l. I was running into an issue where once in a while it would cut out on me during a longer drive (2 hr.). It would cut out for a short period, usually less than one minute... but never killed. A week ago, at a steady 40mph, it backfired 2-3 times and was completely dead.. I shouldered the vehicle and sat for 25 mins as it wouldnt start back up. Once it did, I needed to hold the accelerator to the floor as it was flooded. (i think secondarily). this happened here and there without backfiring, sometimes just wouldnt start after a 5 minute drive and proper shut down.
I was advised to change the pickup coil, as I did.. and rotor, cap, pugs, and wires.
After the change, it ran ok, idled great, started after use etc.. almost like it was fixed, but was pretty doggy if tried to get on it.
The vehicle had the history of flooding very easily, and would if you touched the gas AT ALL, when starting.
Now seems like it floods out real easy, as I can let it idle for 5-45 seconds and it kills, then takes 20-30 mins to start back up w accelerator punched to the floor.
Any ideas, or advice would be greatly appreciated. Sorry for the lengthy explaination and possible missing details.

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