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Unread 02-07-2013, 02:25 AM   #1
Tofu77
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HELP 1987 jeep wrangler running problem HELP

Iv been having a problem with my jeep that I cant seem to figure out what the cause is. I could really use some help trouble shooting the problem as my jeep is my daily driver and only transportation to work.

Ill start off by saying I have a 1987 4.2 cylinder 4x4 5 speed jeep wrangler, it is carbureted. And is stock. ive recently replaced my spark plugs, spark plug wires, fuel filter, rotor, distributor cap.

now for the problem, last weekend I went wheeling in the jeep and went through a small mud whole. After i got out of the whole my jeep just stopped running, got out messed with it a lil and got it running but I had to keep my foot on the gas to keep it running. When I got home I took the distributor cap off and dried out the water, and I unplugged my ICM and blew out the connectors with a compressor started the jeep and it ran fine besides idling at 2000 rpms instead of about 700-800 rpms.
The next day i washed my engine out lightly with a hose. Since then my jeep has acted up worse.
if it has been sitting for 6+ hours I can start it with no problem and it will idle but rough for about 5 min then die. If im driving I have the keep the gas pedal pressed to keep it idling and you can feel the rough idle and while driving(almost like a misfire).
I have a feeling my ICM is bad, but I dont know and nobody I have talked to knows what it could be, most think its a fuel problem, but I know for a fact that is something electrical.

If anyone has any suggestions that might help please tell me.

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Unread 02-07-2013, 04:42 AM   #2
Mark05059
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change your icm. First they dont like water, second they die after heating up usually... Cant hurt to have a spare if it isnt the problem.
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Unread 02-07-2013, 05:20 AM   #3
Jeepsr4me
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Look up Nutter and do that. Do away with all that junk.. cost FREE... well a few feet of wire and a few seconds of your time.
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Unread 02-07-2013, 06:00 AM   #4
Old4X
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Nutter will not fix this problem, not related.

Best course is to put it on an engine analyzer and see what is happening. Idle above normal is either mechanical problem associated with accelerator cable, or wet connections to the sol-vac. These are what set the idle speed on that motor.

ALL these motors should have a dedicated ground for the ICM, none had this from the factory. The black wire in the 3 wire harness on the dizzy is the wire you need to ground.

Your vehicle is more than 25 years old, when was the last time you cleaned and re-bonded the grounds associated with the engine, frame, and body? Also, if it ran better after cleaning the dizzy cap, replace the cap and rotor. They will track up with carbon and you can't really get them totally clean once they have given trouble.
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Unread 02-07-2013, 09:19 AM   #5
Que89YJ
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Hey Old 4X! You don't think getting rid of the computer controlled crap is a good idea? The nutter makes you reground the distributor and the ICM as part of the mod. The rotor trick is to use nail polish on it all the way on the end to prevent arc over. I would replace the ICM as well. They are cheap enough. The best solution is if you are going to run it in mud do the Nutter and get rid of all the emissions control stuff, clean and coat all the connectors under the hood that are left(Which will be very few) with dielectric grease. Clean all the bigger cables like Old 4X said and coat those with a light coat of bearing grease. Get rid of the ICM and look at getting a good HEI system or doing the team rush mod.
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Unread 02-07-2013, 09:37 AM   #6
giggityjeeper
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^^ basically that

water proof your dizzy/wires, vaseline, lithium grease..... it got wet in your water hole and stalled out your jeep....

its pretty common go slower in deep water, it gets wet you stall

the nutter is a GREAT cheap/free mod.....

also look up team rush mod.... and ditch your POS carter carb for a weber or MC2100 if u can as in u dont have emissions check
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Unread 02-07-2013, 10:40 AM   #7
Tofu77
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I know its not the dizzy or rotor, because thoughs were replaced 2 months ago.

Ive tried looking for the nutter instructions and have never been able to get clear instructions, anyone have a link to pictures and instructions?

I figured it had to be my ICM, what can I do to that to avoid the ICM getting wet?
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Unread 02-07-2013, 10:52 AM   #8
giggityjeeper
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Quote:
Originally Posted by Tofu77 View Post
I know its not the dizzy or rotor, because thoughs were replaced 2 months ago.

Ive tried looking for the nutter instructions and have never been able to get clear instructions, anyone have a link to pictures and instructions?

I figured it had to be my ICM, what can I do to that to avoid the ICM getting wet?
replaced or not, it gets wet and your dead...... dont care if its BRAND new yesterday.....

for your ICM just put some lithium greas in and around the connector
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Started with some rust repairs ended in a SOA...

http://www.jeepforum.com/forum/f12/h...-jeep-1050879/

family roll bar swap/upgrade..

http://www.jeepforum.com/forum/f12/f...grade-1054753/

1990 YJ. SOA, OME 36R 3.5" lift springs, OME 5/8 greasable shackles, OTT high steer, Custom cage, team Rush, Posi, 33 TSL swampers
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Unread 02-07-2013, 12:59 PM   #9
Que89YJ
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Ask and ye shall recieve:
Nutter:
http://www.jeepforum.com/forum/f12/p...bypass-476720/

Team Rush:
http://www.jeepforum.com/forum/f12/t...w-pics-586158/


HEI is an alternative to Team Rush. They are all great investments as well as doing the carb swap. Start with the nutter. Free Cheap and Easy!
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Unread 02-07-2013, 03:19 PM   #10
Tofu77
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Thank you, I will look into the nutter, or team rush mod. And I am looking for a ICM online to replace. If the ICM replacement doesn't fix my problem I will post back to see what my next step to finding my problem is.

I've checked my dizzy and rotor and there is no carbon or and condensation in it.
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Unread 02-13-2013, 10:47 AM   #11
Tofu77
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So I have replaced the dizzy, rotor, air filter, and ICM and it has not changed a thing. It's still having the same problem and I'm out of ideas of what it could be!!
Does anyone have anymore suggestions on what to do?
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Unread 02-13-2013, 11:10 AM   #12
Que89YJ
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Like I said: Nutter bypass mod, clean all the connectors and dielectric grease.
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