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AMC HEI Conversion Distributors


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I met a ol' gear head today and he told me about swapping to a HEI Dizzy.. Sooo What y'all think?

http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=7549

 

 

AMC HEI Conversion 232-258 Inline 6 Cylinder Utilizing the durable and dependable High Energy Ignition (HEI) system pioneered by GM, these distributors avoid the unsightly wiring of the stock electronic ignition systems by installing this one-piece distributor with an internally positioned coil and module. Easy to install: just connect one 12-volt hot wire to the distributor (has optional tach hook-up). These units offer calibrated advance curves that are optimized for maximum combustion efficiency and for the elimination of detonation damage and throttle ping. Assembled from precision-made parts for advance curve smoothness. Offers longer term durability and a higher voltage spark that permits a bigger spark plug gap, resulting in more power and reduced plug fouling. Each unit includes a high-power coil, a premium hi-dielectric cap with brass terminals, and a low-saturation ignition module.

ph_7549.jpg

 

Not bad for a $160 price tag... :dunno: :dunno: :dunno:

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What do you plan to use it in? It's completely incompatible with either the Renix or Chrysler injection/ignition systems. This thing is what was used to replace the old points-and-condenser distributors from the 1960s.

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  • 3 years later...

Eagle, please elaborate on your statement of moving backwards in technology. I have an 1988 MJ w/ 4.0l and maybe there's something you could share that'll be helpful for my project and other peoples projects. I've done an HEI setup before but that was on a CJ. So I am somewhat familiar with the workings of the HEI system, but unclear on the specific affects if installed on a renix or chrysler fuel injected engine. This subject if searched for on many forums has little to no useful info specifically in regards to our beloved Comanches.

:cheers:

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Nothing like going backwards in technology.

 

The ignition system in your '89 replaced that distributor you want to waste good money on.

Got to agree with Eagle on this. The HEI was a vast improvement over the old points and condenser ign system. However it can only operate on a fixed preset conditions.

The computer systems can alter their output to match changes in conditions, temperature, overheating, pre ignition etc. The HEI can't. The only time I can see replacing the Renix-HO with a HEI is if your replacing the engine in a earlier model Jeep (with distributer) with one from a later model (Renix, HO ).

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Usually, people only swap in a HEI for FSJs, because most of the time its somewhat of an improvement for the antiquated technology found in the 258s, and small block AMC V8s. With that being said, the HEI is only useful because these engines were bogged down with an overabundance of electrical wiring from the factory setup; most of it was to control lousy and over-designed emission crap. Believe me when I say this, you're better off with keeping a Renix/HO ignition distributor than going to an HEI setup. If you've ever seen the inside of a 70s and 80s Full Size Jeep, you'll know why.

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Well I learned something new today. And I really appreciate you guys with all of the input. Bc I have been considering HEI and I googled the shenanigans out of this topic for the MJ with no results. Thanks again.

:thumbsup:

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I have used HEI in three of my Eagels and it was a big improvement over the stock setup but as others have already stated, HEI can not manage the spark as well as the factory set up on our inline six cyclinder engines.

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Up through at least 1969 the AMC engines still used conventional points and condenser and a conventional ignition coil for spark. Somewhere in the early to mid-1970s they changed over to a transistorized distributor (no more points and condenser), but the coil remained essentially the same as it had been for decades previous. This HEI (High Energy Ignition) distributor is basically nothing more than a modern version of the transistorized distributor from the 70s. Unless you are replacing an older points-and-condenser distributor, it doesn't really do squat for you. It's best used in conjunction with a high-energy ignition coil.

 

But ... the coil in the Renix and Mopar XJ/MJ systems is already a high-output coil, and the distributor is already a breakerless (no points or condenser) distributor, so there's no gain. Beyond that, as jimoshel mentioned, in the MJ systems (both the Renix and Mopar) the timing is controlled by the ECU based on a variety of inputs, to optimize spark timing to operation. With an old-school (comparatively) HEI distributor, the ECU can't talk to it so you're back to controlling the spark timing just be engine RPM and perhaps engine vacuum (if it has a vacuum advance port). That's why I commented three years ago when this thread was fresh that the HEI distributor is going backwards in technology.

 

Compared to the stack Renix or Mopar systems, the HEI doesn't gain you anything and very likely loses a lot.

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Wow impressive explanation thank you so much. So I guess my next question would be if I want to improve upon the current setup on the 4.0 Renix ignition system. What kind of mods should I look into? Other than just replacing oem parts i.e. sparkplugs, rotor, etc.

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Usually, people only swap in a HEI for FSJs, because most of the time its somewhat of an improvement for the antiquated technology found in the 258s, and small block AMC V8s. With that being said, the HEI is only useful because these engines were bogged down with an overabundance of electrical wiring from the factory setup; most of it was to control lousy and over-designed emission crap. Believe me when I say this, you're better off with keeping a Renix/HO ignition distributor than going to an HEI setup. If you've ever seen the inside of a 70s and 80s Full Size Jeep, you'll know why.

 

 

I'm doing a Ford TFI on my FSJ.... I want the least amount of GM junk on it as possible. But that reuses the stock Motorcraft dizzy.

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Wow impressive explanation thank you so much. So I guess my next question would be if I want to improve upon the current setup on the 4.0 Renix ignition system. What kind of mods should I look into? Other than just replacing oem parts i.e. sparkplugs, rotor, etc.

 

Nothing other than using good quality cap and rotor with brass terminals, Champion copper or NGK plugs, Belden ignition wires from Napa.

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Wow impressive explanation thank you so much. So I guess my next question would be if I want to improve upon the current setup on the 4.0 Renix ignition system. What kind of mods should I look into? Other than just replacing oem parts i.e. sparkplugs, rotor, etc.

Cap+rotor+plug wires.

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  • 2 years later...

I know this is bring up old thread.

I have a 87 and followed the Renix tips from cruiser. I replaced the computer, every sensor, dizzy, took out the 101 connector and wired straight up, and still get rough idle.

I tried 3 different computers, and even rewired one by one every wire.  I put new cap and rotor with brass terminals, Champion copper NGK plugs and Belden ignition wires. Still rough idle.

I bought a HEI and dropped it in and smooth idle on 1st start. The only problem I had was vacuum advance since there is no right place to connect it. I drove it around with advance off and it was amazing. Only suffer 2 mpg.

For me it seemed to fix the problem however I would like to have the Renix ignition system working right.

 

3 months ago I took out the 4.0 and rebuilt it from bottom up. Replaced everything and every sensor again. I did not hook up the HEI and stuck with the renix. Rough idle on newly rebuilt motor still. Now when I say rough idle it does not shake or anything like that. When it starts from cold it idles around 955 to 1025 rpms for warmup time about 75 secs. Then it gos down to 560 to 815 rpms. it will go up and down from 560 to 815 all day long. It does not bog down on start off or die. It never bogs even when I stomp on it. Just that damn idle is bothering me. Since here in Texas my truck is exempt and only needs to pass visual I have done some mods. It has improved idle a bit. Mods are the cruiser advance timing, spectra intake air filter. Straight exhaust with high flow cat.

 

I may try the HEI again if I can not find what the problem is.

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Have you tried replacing your renix dist with a new or used (but known to be good) dist?  The dist could have worn bushings, or a cracked dist shaft, or other defect that contributes to the bad idle.  Also, I seem to remember reading somewhere that the dist gear could be put on two ways, but only one is right, the other way would cause the timing to be off.  Can't remember if that is a Jeep motor or something else...

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I know this is bring up old thread.

I have a 87 and followed the Renix tips from cruiser. I replaced the computer, every sensor, dizzy, took out the 101 connector and wired straight up, and still get rough idle.

I tried 3 different computers, and even rewired one by one every wire.  I put new cap and rotor with brass terminals, Champion copper NGK plugs and Belden ignition wires. Still rough idle.

I bought a HEI and dropped it in and smooth idle on 1st start. The only problem I had was vacuum advance since there is no right place to connect it. I drove it around with advance off and it was amazing. Only suffer 2 mpg.

For me it seemed to fix the problem however I would like to have the Renix ignition system working right.

 

3 months ago I took out the 4.0 and rebuilt it from bottom up. Replaced everything and every sensor again. I did not hook up the HEI and stuck with the renix. Rough idle on newly rebuilt motor still. Now when I say rough idle it does not shake or anything like that. When it starts from cold it idles around 955 to 1025 rpms for warmup time about 75 secs. Then it gos down to 560 to 815 rpms. it will go up and down from 560 to 815 all day long. It does not bog down on start off or die. It never bogs even when I stomp on it. Just that damn idle is bothering me. Since here in Texas my truck is exempt and only needs to pass visual I have done some mods. It has improved idle a bit. Mods are the cruiser advance timing, spectra intake air filter. Straight exhaust with high flow cat.

 

I may try the HEI again if I can not find what the problem is.

 

 

MAP

ICA

TPS

O2

Or vacuum leak

 

 

It's one of those.

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I replaced MAP, ICA, TPS, O2 and all vacuum lines. I even rebuilt the throttle body and put new line in for the map from it. I put new vacuum ball in and new lines for it too. I have replaced everything at least 2 times. I use this truck on my farm and it works great. Never had any issue other then the rough idle since I bought it in 1997.  

 

Yes I replaced dizzy. I have 2 extra ones and all work the same. I have enough parts to build three engines lol

 

I replace the intake manifold and gasket. I did a leak test and nothing. I redone all vacuum lines and gaskets on whole engine.

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Now I do remember I replaced the ecu about a year ago and it ran great on first start up. Then after a few minutes it started running crazy. from idle to 2500 back forth so on. I shut it off and that ECU never worked again. I have 2 other ecu's I have tried they all run the same no change in running at all. I did all new wiring for ECU from sensors to plugs. I have had this issue since 1997 and with nothing I have ever done rough idle never went away till the Hei was put in. I am super stumped. Over the past 18 years I have had many people who know about remix's look at it and they are just as stumped as I am.

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TPS is adjusted correctly?

yes I have it set right at 0.8 volts

 

The orifice from the TB to the MAP is clear? not clogged?

Yes it is clear and all knew. When I rebuilt the TB I replaced it. Also checked it for vacuum leak and it hold vaccum. So new map, new line and new plastic orifice in TB 

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The GM HEI style ignitions are great upgrades for any of the pre-renix AMC crap. The motorcraft /ford type system that replaced their points ignition was inefficient and unreliable. It was used into the 90's on the 360. You will notice an immediate difference in starting and revving with this conversion. This is common knowledge in the FSJ world and also in the AMC hot rod circles. However it does not apply to renix or OBD 1 MJ's.

 

And BTW: AMC did not have a small and big block. The 304/360/401 (and their immediate predecessors ) were all the same physical dimensions.

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