Still Need MUCH Help with my 86 CJ!!! - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 02-24-2003, 07:28 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Still Need MUCH Help with my 86 CJ!!!

Hello all, It's me again. Incase you haven't heard, I have a 86 CJ that is making me grey! I have been having trouble with it back firing and pop popping alot. I've replaced just about everything.I checked the ignition wiring as well, it looks good. Today, I figured that I would try to blow some crap out of the intake with some Mystery oil down the carb. Then I bought a high daller gas treatment. Were am I going with this , you ask? Well, I'm thinking now that maybe it is my valves after all. Then I drove it and it drove pretty well. Some tiny pop pop, but other than that, like a champ. Then I took it out tonight, and it drove terrible!!! When I got back home I turned my head lights out and the engine picked up and no pop pop. Then I turned them back on and 1 pop. Then off, nothing. Then on, 1 pop. All this time the engine is up and down. Like it's being strained considerably. Does this strike an idea with anyone. One more thing. When I drive it between the pop pops, and I'm in a good gear and press the pedal to the floor it respones GREAT, then all of a sudden while im still pedal down, it will back down and pick up, back down and pick up. Kinda like if you were to start to run out of gas (exp. verrrrrr mmmmmmmmmmm verrrrrr mmmmmmmmmmmm) The "ver" is to accelerate and the "mmmmm" is the "not" planed decereration. Any ideas you have, would be a HUGE help!!!!!! [img]images/graemlins/thud.gif[/img]
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 02-24-2003, 07:38 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

1. Grounds are bad.
2. Repair the ground circuits.
LEVE is offline  
post #3 of (permalink) Old 02-24-2003, 07:40 PM
Old Hand
 
Skellator's Avatar
 
Join Date: Aug 2000
Location: Conowingo, Md.
Posts: 1,124
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

</font><blockquote><font class="small">In reply to:</font><hr />
When I drive it between the pop pops, and I'm in a good gear and press the pedal to the floor it respones GREAT, then all of a sudden while im still pedal down, it will back down and pick up, back down and pick up. Kinda like if you were to start to run out of gas

[/ QUOTE ]


My 1980 Volare did that for a while, turns out the wire for the balast resistor was making intermitten contact. Just a thought. [img]images/graemlins/burnout.gif[/img]
Skellator is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 02-24-2003, 07:47 PM
BigUgly
Guest
 
Posts: n/a
Re: Still Need MUCH Help with my 86 CJ!!!

What engine do you have? How many miles is on it? Have you tried a vacuum line check? The way you check this is take a can of carb cleaner and spray it on the lines, if you hear the engine rev then, that's where the leak is. I could be a bad carb flooding or fuel pump that is cutting out. A plugged gas filter might do that to you. These are the easy things to check. The harder things are a flat lobe on the cam. In "The BigUgly", my `73 Blazer it has a 350 v8, I bought it as a tow away because of backfiring at 55mph. It idled fine and ran good until about 2500 rpm, then pop, it backfired and did about the same thing as you say. I bought it with about 98k miles on it and now it has 189k and all I did was change the cam and lifters. Good luck,




TheBigUgly
post #5 of (permalink) Old 02-24-2003, 09:46 PM
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

Something is obviously intermittant. Those are the hardest ones to find. Gotta figure out if it's spark or fuel that's degrading or cutting out. You could put a t fitting in the fuel line after the pump and put a gauge under your windshield wiper arm and watch it as you drive. No fuel lines in the passenger compartment please.

I'm trying to figure out if there is a way you could monitor spark quality as you drive. You need one of those old neon timing lights you put in series with the spark plug wire, and stick that up under your wiper arm. You could see if the spark dies off when the motor starts to die.

As Leve suggested, it sure could be electrical. Those components can warm up and become intermittant. I had a car that had a bad pickup coil in the distributor and I never figured it out till I swapped out the distributor. Something happened after running it for a while and it would cut out. I couln't find the fault with a meter, even after heating up the part with a blow dryer.

The backfiring and power loss are also consistant with the mixture going lean. That would be either dirt plugging the pickup in the tank, pump problem (??? but intermittant????), dirt in the filter, needle and seat problem or dirt in the carb. Dirt can move around and clog things up then unseat after the motor dies off demand again.

Does it ever just die? If so, push in the clutch, coast to a stop and pull out the plugs. See if they are wet with fuel (ie the spark died), or scorched white from a lean mixture (fuel supply problem). Obviously I'm grasping at straws here. Takes a better man than I to come up with a systematic approach. It would be good to know at least which camp to side with (spark or fuel).
TiminMb is offline  
post #6 of (permalink) Old 02-24-2003, 10:43 PM
 
Join Date: Aug 2001
Posts: 395
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

If you still have the computer hooked up to the carb, that's probably the place to start. Rip it out, and all the vacuum lines that go with it. Search on Nutter Bypass and Motorcraft 2100 carb. Otherwise you need to find an old school mechanic who understands the computer feedback carb system and open your wallet wide.
80sCJ7 is offline  
post #7 of (permalink) Old 02-24-2003, 10:53 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

</font><blockquote><font class="small">In reply to:</font><hr />
Then I drove it and it drove pretty well. Some tiny pop pop, but other than that, like a champ. Then I took it out tonight, and it drove terrible!!! When I got back home I turned my head lights out and the engine picked up and no pop pop. Then I turned them back on and 1 pop. Then off, nothing. Then on, 1 pop.

[/ QUOTE ]1. OK, now sit down and think!
2. You've done a lot of work on that Jeep, and it's helped,
3. However, the symptom you describe is directly related to voltage.
4. Voltage is the life blood of the ignition system.
5. Try driving a Jeep with a constant loss system... or the alternator ain't chargin'.
6. You'll do fine as long as the voltage is above about 11 volts.
7. The second the voltage drops below about 10.8 volts, all hell breaks loose.
8. No you turn on the lights, and guess what's happening?
9. I'd almost bet the voltage is dropping... but why?
10. Well, it could be the dimmer switch is bad, corroded,
11. It could be the light switch is bad, corroded,
13. You've got to check those items out to rule them out as a problem.
14. You've got to rule out the grounds because current returns via the ground.
15. If the grounds are corroded you'll get lots of strange problems.
16. So, again I'm gonna say:
a. Check your grounds.
b. Check the quality of the headlight swtich,
c. Check the quality of the dimmer swtich/connector,
d. Check the quality of the headlight wiring and connectors.
17. Make sure the symptoms are repeatable by turning on the headlights,
18. If they are you've found a very important clue.
LEVE is offline  
post #8 of (permalink) Old 02-24-2003, 10:55 PM
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

When I think of all the hoses, cto swiches, check valves, sol-vac, vacuum switches and wiring involved in the 80's emissions system the name Rube Goldberg comes to mind and the word "contraption" as well (kinda like that mousetrap game). Elegant solution definately does not apply to what they put under the hood of our jeeps. Too many mechanical failure prone parts. I simply unplugged my stepper motor and it ended an erratic idle.
TiminMb is offline  
post #9 of (permalink) Old 02-25-2003, 07:15 AM
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Still Need MUCH Help with my 86 CJ!!!

Leve's right, it's got to be electrical if it is affected by your headlights. I was too tired last night and didn't pick up on that (even though it was in writing before my eyes!).
TiminMb is offline  
post #10 of (permalink) Old 03-01-2003, 09:54 AM
**DONOTDELETE**
Guest
 
Posts: n/a
It\'s fixed!!! LEVE, you have saved the day!!!

It's fixed!!! LEVE, you were 100% correct sir!!! I went out side and looked at all the grounds. I never could find the ground from the moto to the body, so I made one, just incase! Then I looked over at the ground from the moto to the frame and guess what? You guessed it, it was loose, loose, loose!!! So I toke it off sanded it and the moto contact down and tightened her up. She purrs like a kitten now. It's amazing after all that time and money I spent on replacing items that it breaks down to just a ground! I never noticed the light going dim and the volt drop until the last time and I posted and you answered. Thanks for the help man, and thank you to the rest of you that added a helping hand!!! <font color="red"> </font color> [img]images/graemlins/40BEER.gif[/img]
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome