HEI problem? - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

Reply
 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 12-06-2001, 09:14 AM Thread Starter
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
HEI problem?

I've been experiencing temporary rough running of my engine during wet or snowy conditions. I'm guessing it's related to the ignition, and most likely the high tension end of things. Cap, wires and rotor are about 4 years old now. Plugs about 2 months old. I'm thinking it's time to replace them all (cept the plugs). Is the 80's Ford Fairmont with 200 cid inline six still the best fit for wires? Is there any possible problems that I haven't thought of here, like the actual coil (it's still the original from 198?).

Tim

84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, 4.56's and Detroit softlocker, full cage & belts, Xenon flares, Dana 44 rear, GM dual diaphragm brake booster
TiminMb is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 12-06-2001, 11:32 AM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Re: HEI problem?

I think TR'd address crossfiring inside the cap. The air ionizes, and moisture, sure don't help and it tends to either crossfire or disapate the energy. Try a new cap. Ohm out the wires to see if they meet spec. and then try, at night, running the engine and spritzing a little water on the wires to see if you can cause and see an arc... if you can... you found the problem.

LEVE is offline  
post #3 of (permalink) Old 12-06-2001, 11:55 AM
I Might Just Know What I'm Talking About
 
Pete88YJ's Avatar
 
Join Date: Sep 1999
Location: BOSTON
Posts: 1,748
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: HEI problem?

I assume you've at least looked at the condition of the cap and rotor a few times in 4 years? [img]/wwwthreads_images/icons/crazy.gif[/img]

I try to replace that stuff once every year or so.

Good luck
Pete

"Don't fall into the traps laid by society" -- Henry Lee Summer.
Pete88YJ is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 12-06-2001, 12:02 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: HEI problem?

Tim a better fit for the wires are those from a 4.0 Wrangler. The Ford wires are close, but the Jeep ones are much better.

'75 CJ5 with goodies
post #5 of (permalink) Old 12-06-2001, 12:53 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: HEI problem?

I'm placing my bet on a cross firing cap.
This is exactly how mine drove everytime it rained until I did the TR.


'88 Sahara, 4.2 that runs thanx to every Cheap trick on this board. The rest is getting there![img]/wwwthreads_images/icons/blush.gif[/img]
post #6 of (permalink) Old 12-06-2001, 01:28 PM Thread Starter
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: HEI problem?

I'll have to look at a set of 4.0L Wranger wires. You did mean they fit on the HEI distributor cap?

Too bad it's so damn cold out there right now. I'd like to drill a hole in my old cap and check the distributor phasing to make sure the rotor is lined up closely with the strip under hte cap. Doing the HEI conversion you end up phasing / indexing the distributor as close as you can, and I wonder how far one tooth on the drive gear moves the rotor?

Tim

84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, 4.56's and Detroit softlocker, full cage & belts, Xenon flares, Dana 44 rear, GM dual diaphragm brake booster
TiminMb is offline  
post #7 of (permalink) Old 12-06-2001, 02:14 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Re: HEI problem?

Tim... I've got a spare HEI in the garage... I'll count the teeth. Divide 360* by the number of teeth and you've got the amount of degrees one tooth off will index the distributor.

LEVE is offline  
post #8 of (permalink) Old 12-06-2001, 02:45 PM Thread Starter
 
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: HEI problem?

Leve or anyone, can you tell me how the hei's coil in the cap is grounded? I see a red wire for power,yellow for tach, and a black wire on a scew terminal that connects the guts of the coil to the iron transformer core. But nothing hooking the coil up to chassis ground? What is the ground path?

Book says there is either a ground wire or strap. I have neither. Should I run a wire from the coil's iron core to chassis ground? (distributor housing?) (after all, it's hooked up to the coil's black wire).

Tim

84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, 4.56's and Detroit softlocker, full cage & belts, Xenon flares, Dana 44 rear, GM dual diaphragm brake booster
TiminMb is offline  
post #9 of (permalink) Old 12-06-2001, 02:56 PM
 
Join Date: Sep 1999
Posts: 5,383
Thanks: 0
Thanked 1 Time in 1 Post
 
Re: HEI problem?

LEVE is dead right on this one...
4 years is 4 lifetimes for a stock HEI cap and rotor!

Make sure you buy a PREMIUM cap and rotor, or you are just wasting money with the GM HEI.

If you still have the factory resistor wire in place, you may want to look into a power relay for that HEI, because you are limiting spark potential something fiercely with the resistor wire feeding the HEI.

The plug wires you are looking for will come from a 250 CID I-6 Chevy engine, out of probably a '80 pick up truck.
They will have the little 'nubs' on the top of the distributor boots for the stock distributor wire keeper to get a grip on, and they should fit your engine just fine.

Rotor phasing is a real concern for this type of alteration.
The AMC V-8 drive gear isn't indexed for this application, and you will do well to check the rotor phasing with the old cap before tossing it out...
I use my Dremel tool for just chopping a hole in the cap, but you can use what ever high tech device you want to...
--------------

Did you know that GM had an I-6 distributor WITHOUT the coil in the cap?
The distributor used in '76 on 250 CID Chevy pickups had a remote coil, but still used the same distributor base.
The cap is still large, but the rotor is still short...
Coil removed from cap was a great leap forward, but they didn't keep it long. Too bad.

BTW, it should be 13 teeth...
About 28 Degrees per tooth, but you will usually have less than one tooth to move.
The idea is to get the 'Advance Sweep' (The point form no advance to full advance) to start on one side of the correct terminal, and advance right past the terminal to the other side of the terminal in even spacing on both sides. (Like 1/8" before the terminal to 1/8" after the terminal)
This will take some monkeying around with the trigger usually, not the drive gear.

Ignition coil primary circuits are grounded through the ignition module.
Ignition coil secondary circuits are grounded through the spark plugs, that's how they discharge...


So many cats, so few recipes...
Junk Yard Genius is offline  
post #10 of (permalink) Old 12-06-2001, 02:58 PM
Way Outta Control
 
Join Date: Sep 1999
Location: The Palouse
Posts: 13,432
Thanks: 1
Thanked 3 Times in 3 Posts
 
Re: HEI problem?

1. Bad News on the tooth count... I pulled the junk box and the distributor's minus a shaft... and gear... so much for that bright idea...[img]/wwwthreads_images/icons/crazy.gif[/img]
2. The body of the coil ain't grounded.

The coil is part of the voltage circuit that follows the voltage
....from the souce through the coil
....... to the ignition module through the module
............. to ground via
...................the distributor body...

if I remember correctly.

LEVE is offline  
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