[Shawn Watson]

I would say most-definitely. Now the question is "why" and I'm no good with electrickery. I'd try to find your ballast resistor and check the voltage before and after it. Maybe it's shot to hell.


Shawn

 

[Ken4444]

Used a volt meter to see what kind of volts I'm getting. Battery is at 12.5v, Positive in to the starter solenoid is 12.5v, but only 4.5v are actually getting to the coil. Could this be my problem? New starter solenoid?

This is a wild a$$ guess, but when I did the HEI install on my '85, I remember something about a factory-installed resistor (or resistor wire) that was used to limit the voltage to the OEM coil, and I needed to bypass this to get full voltage to the new HEI unit. I found a Jeephammer diagram that might support this. Look for the "Ignition resistor" in the diagram below.

On the other hand if you're seeing only 4.5 volts, then that might be too low, even considering a resistor that might be there.

Here's a page from the good book of Jeephammer with detailed troubleshooting procedure:

http://www.jeepforum.com/forum/f8/icm-coil-voltage-question-1296641/#post12612259

 

[zrstonestreet]

I would say most-definitely. Now the question is "why" and I'm no good with electrickery. I'd try to find your ballast resistor and check the voltage before and after it. Maybe it's shot to hell.

Shawn

Thanks for the info fellas.

I read that these jeeps use a resistor wire, not a ballast resistor. But if the resistor is shot, wouldn't I be getting the full 12v to my coil, not amplified resistance?

This is a wild a$$ guess, but when I did the HEI install on my '85, I remember something about a factory-installed resistor (or resistor wire) that was used to limit the voltage to the OEM coil, and I needed to bypass this to get full voltage to the new HEI unit. I found a Jeephammer diagram that might support this. Look for the "Ignition resistor" in the diagram below.

On the other hand if you're seeing only 4.5 volts, then that might be too low, even considering a resistor that might be there.

Here's a page from the good book of Jeephammer with detailed troubleshooting procedure:

http://www.jeepforum.com/forum/f8/icm-coil-voltage-question-1296641/#post12612259

I read through JeepHammer's write-up, and will perform the procedure when I get back to my jeep. I definitely think it's ignition/electrical based.

MSD's website says:

"The ballast is not necessary if an MSD 6 or 7-series Ignition Control is being used with the points distributor."

Does this mean I can splice the ignition wire directly to the the 'I' wire going to the coil if I get the MSD 6A?

Or should I order a ballast resistor since the original setup had a resistor wire?

Been saving up for the MSD 6A for a while now, might go ahead and pull the trigger while I'll be pulling plugs and testing stuff. Is it okay to get the standard 6A, or is there an 'offroad' or 'marine' one I should be looking at instead?

 

[Shawn Watson]

In my humble and often refuted opinion, I'd scrub the MSD idea and go with a D.U.I. It's a simple installation and better for these applications.


Shawn

 

[zrstonestreet]

In my humble and often refuted opinion, I'd scrub the MSD idea and go with a D.U.I. It's a simple installation and better for these applications.

Shawn

**insert horrible joke about drinking and driving here** lol

But in all honesty, why would a DUI be more beneficial than a setup using separate pieces that every autoparts store carries on demand? I already have the MSD coil and my setup has the team rush upgrade.

I'm not shutting down the idea, I'm definitely open-minded about it, but I need to be persuaded haha if my coil has somehow already burnt up from this issue, I'll probably be even more attentive to your proposal..

 

[Shawn Watson]

Well that's just it. You can carry a spare cap, rotor and module in the Jeep that are also available anywhere to replace if something on the D.U.I. goes bad. If your MSD box craps out, you're screwed.

Plus, MSD's marketing department loves to say "multiple sparks below 2,500 rpm ensure a complete burn..." which is complete bs. The truth is that the tiny, lightning bolt crack that CDI boxes produce will barely run down low so they have to zap them 5 times per cycle in hopes of getting the fire lit.

That long duration, yet still very hot spark you get from a D.U.I., in my opinion, is the only way to go. Unless you're winding 7,000 rpm. I'm way outnumbered on JF with this opinion but it is what it is.

Also, you'll need a pre-81 distributor if you want a centrifugal curve so factor that in as well.


Shawn

 

[zrstonestreet]

I'm way outnumbered on JF with this opinion but it is what it is.

Also, you'll need a pre-81 distributor if you want a centrifugal curve so factor that in as well.

Shawn

Well Shawn, I'll definitely give it some thought.

And what does that whole last statement even mean?

 

[Shawn Watson]

The computer used to control your advance curve. It's now out of the loop so you need a pre-computer distributor that has a mechanical advance curve for your engine to run "correctly".

There should be a ton of threads regarding this topic. Buckle up, lol


Shawn

 

[zrstonestreet]

I thought timing the motor to 8* BTDC took care of the advance curve? The motor seems to run pretty well when it actually starts lol or are you talking about only when doing the D.U.I.?

 

[Shawn Watson]

Here you go... http://www.hotrod.com/articles/ccrp-0512-ignition-advanced-basics/

 

[Matt1981CJ7]

I thought timing the motor to 8* BTDC took care of the advance curve? The motor seems to run pretty well when it actually starts lol or are you talking about only when doing the D.U.I.?

Initial timing is just for starting the engine. The advance curve Shawn is talking about applies to higher RPMs.

Without the computer, your engine needs around 30* of centrifugal advance at 3000 RPM to run efficiently. Your distributor only provides about 7*.

Matt

 

[zrstonestreet]

Initial timing is just for starting the engine. The advance curve Shawn is talking about applies to higher RPMs.

Without the computer, your engine needs around 30* of centrifugal advance at 3000 RPM to run efficiently. Your distributor only provides about 7*.

Matt

So I have to get a distributor off of an 81 or older cj that provides the advanced timing? I have the distributor manifold vacuumed, not ported, will the centrifugal curve make up for the difference between cracked throttle and WOT?

 

[zrstonestreet]

Well that's just it. You can carry a spare cap, rotor and module in the Jeep that are also available anywhere to replace if something on the D.U.I. goes bad. If your MSD box craps out, you're screwed.

Plus, MSD's marketing department loves to say "multiple sparks below 2,500 rpm ensure a complete burn..." which is complete bs. The truth is that the tiny, lightning bolt crack that CDI boxes produce will barely run down low so they have to zap them 5 times per cycle in hopes of getting the fire lit.

That long duration, yet still very hot spark you get from a D.U.I., in my opinion, is the only way to go. Unless you're winding 7,000 rpm. I'm way outnumbered on JF with this opinion but it is what it is.

Also, you'll need a pre-81 distributor if you want a centrifugal curve so factor that in as well.

Shawn

I'm going with you on this one. Contacted Tom at Redline again, and my new H.E.I. Distributor should be here this week. By far, the best customer service you could ask for; for both technical advice and getting the correct parts. I was definitely supporting the idea of having the entire CDI system made up of all MSD parts for not only under-hood presentation, but also dependability.. But, the H.E.I. system is so much simpler when it comes to limiting points of failure. Now instead of an ignition failure "possibly" being the ignition control module, or the resistor wire from the switch, or the coil, or the ECM, or the power supply/ground to any of these... The H.E.I. distributor has one power connection, no resistor wire, eliminates the ICM, ECM, and the separate coil, and all the wiring garbage that goes along with them. Also, one other thing to consider if you're thinking about switching to the H.E.I. is the location of everything. Currently, your stock jeep's ICM is on the back of your driver's side fender, below the windshield washer reservoir... If you plan on going into water deep enough to touch the bottom of the body, the ICM is extremely vulnerable to water damage. I believe water and electrical ignition components are all factors of a bad day. Really looking forward to how the new H.E.I. will perform with the Weber 38. Not that I'm trying to make my jeep run like the buggies on MadRam11's youtube page, but I believe the ol CJ should get some pep in her step. So, thank you Shawn and Tom for your help in making this decision, and I'll keep you posted with the project.

 

[Ken4444]

You can carry a spare cap, rotor and module in the Jeep that are also available anywhere to replace if something on the D.U.I. goes bad. If your MSD box craps out, you're screwed.

I have a DUI HEI ignition on my 258 with a Weber 38. For anyone who does the DUI route (or a generic HEI ignition), carry a spare ignition module ($50) and be sure the DUI is grounded well. I added a dedicated ground from the internal ground wire to my dedicated ground bus bar. The ignition is supposed to ground through its contact with the engine block, but having a dedicated ground wire helps rule out a poor engine ground.

If your engine craps out and you're not getting any spark, it's a 10 minute job to replace the ignition module in the HEI housing, but if you add a dedicated ground wire, there is less chance of frying the ignition module.

As I've written many times before, the combination of the Weber 38 and the DUI really woke up my 258. The DUI gave me a great increase in power at higher speeds, such as when getting on the freeway and maintaining freeway speeds (50 to 65 MPH). The Weber 38 brought an improvement at all speeds as well as reliability and quick starting.

If I ever had to work on another 258, I would do these two upgrades early on in the project.

 

[zrstonestreet]

Heading home tonight and starting the HEI install tomorrow. Will be removing all wiring for ECM and ICM tomorrow. Any advice before I get started? I want to do a thorough installation procedure and review on it, should I start a new thread or just keep it on here?

 

[Ken4444]

Heading home tonight and starting the HEI install tomorrow. Will be removing all wiring for ECM and ICM tomorrow. Any advice before I get started? I want to do a thorough installation procedure and review on it, should I start a new thread or just keep it on here?

I would post a new thread. When I removed some of the factory the wiring from my '85 after doing the Nutter and removing some of the parts for the old feedback carburetor system, I started the engine after cutting 1 or 2 wires. This helped ensure I didn't yank out something that was actually important. Then I shut off the engine and find the next wire to remove. My '85 had the original diagnostic connector on the passenger side between the battery and the fender, and many of the wires I removed were for that. Also the ECM had plenty of wires going to it too.

 

[zrstonestreet]

I would post a new thread. When I removed some of the factory the wiring from my '85 after doing the Nutter and removing some of the parts for the old feedback carburetor system, I started the engine after cutting 1 or 2 wires. This helped ensure I didn't yank out something that was actually important. Then I shut off the engine and find the next wire to remove. My '85 had the original diagnostic connector on the passenger side between the battery and the fender, and many of the wires I removed were for that. Also the ECM had plenty of wires going to it too.

I'll start a new post. I've read your thread MULTIPLE times on the PNBWR. I'm sure the engine bay will be about spotless after this H.E.I. install since I no longer even need the famous orange and purple wires and all that garbage anymore.

 

[Bigdog223344]

Great write up. Thx