HEI conversion problem - any input?

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BB73Challenger

BB73Challenger

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OK here's my application...

1967 273
2 barrel
mostly stock
was points ignition

Here's the problem...

Starts great.
Idles great.
Rev the engine and it flat lines around 1500 - 2000 RPM.
When I have my dial back timing light hooked to the #1 wire or any other and the engine is running, I get the steady flash at idle.
Run the RPM's up and the car won't rev above the 2000 ish mark and the light stops. No flash.

I've read and re-read other posts and I know I'm missing something simple.
I pieced my ignition together on Rock Auto
1974 318 distributor
New LX301 module
New e-core type coil ( 1988 Blazer 350 ci Chevy PN C611)
Relay sending a new power supply to module and coil ( double checked voltage to both )
Also checked and double checked ground/s.
I did need to "swap" my distributor wires the 1st time that go into module. It was a no start before that.
I also kept my set-up close and simple.
My relay is right next to my module, which is right on the firewall above the motor.
I do have that mounted on a 3/8" thick piece of aluminum for heat sink.
The coil is on a home made bracket right where the old coil was. So I don't have long stretches of wire. I also ran my distributor to module wires in a wire loom.

What if I had to "guess" is my hang up is my previous cheap copper core spark plug wires.
I have no problem in upgrading them, but want to get it right, so was thinking a spiral core.

So please hit me with any thoughts on what I missed, and thanks in advance.
 
You are running a full 12 volts to the coil correct? If not low voltage will do this. Remove the ballast resistor. You may also need to power the ignition from a relay using 10 ga wire from B+.
 
It could be the copper core plug wires. The resulting EMI may be causing the HEI coil current limit to cut in at low current. That would limit the RPM.
 
Yes was very concerned about not enough voltage.
I removed the ballast resistor and I am using that lead to trigger my relay.
I am getting good voltage to the coil and module.
My 12 volts is 10 ga wire from the Bat. terminal from the starter relay.
It is fused.
 
KitCarlson said:
It could be the copper plug wires. The resulting EMI may be causing the coil current limit to cut in at low current, due to noise.
Click to expand...

I'm hoping this is the case, I feel I'm very close.
I just wasn't sure if this seemed possible.
 
KitCarlson said:
It could be the copper core plug wires. The resulting EMI may be causing the HEI coil current limit to cut in at low current. That would limit the RPM.
Click to expand...

I didn't catch that, resistor core wires are what you need for sure.
 
Does your radio sound like a Fukushima gieger counter with those wires?
 
I bet the neighbors will appreciate the new wires too. I wonder what the TV looks like!
 
Try a factory GM module,the china ones are garbage.Bought a similar kit from a member on here and had a bad mis at around 3000 replaced the china module with one out of old junker and ran like a top.
 
Did you ground the body of the HEI module, i.e. at the mounting screws, and I don't mean just a sheet-metal screw into the painted body of the car? Did you twist the pickup wires from distributor to HEI module?

Post a photo. One guy asked a similar "HEI don't work" question here and when he finally offered a photo it was of gomered wires all over the place w/ alligator clips and such as his "production" setup. If you don't twist the pickup wires, they can pickup from the spark wires and thus "self-excite". Also, view the plug wires in the dark to see if sparks are jumping to ground. Finally, not all dbl-bullet connectors are correct. I bought 2 Mopar pickups a few years ago and one had the wrong connector so that the male tips didn't firmly connect. It was a standard appliance type connector that the Chinese factory must have thought was correct.
 
Well I did the wires and now I'm having a run issue.
Not related to the wires I'm sure, but now the car won't continue running.
Starts fine, idles good, and now won't run long enough for me to pull it in/out of the garage.

As for a ground wire I did run a direct line from the unit itself to the ground to body wire off the back of the engine
I also did " braid " the coil pick up wires and tuck them into a wire loom.

I had an old Pertronix oil filled coil laying around, so I put it on and the same symptoms.
I tried running "direct jumpers" from the battery for 12 volts pos and ground, same results.
Tried thinking maybe this "new" stalling after 10 seconds problem was fuel related, and I've run through an arms length of remedies.
Replaced all rubber lines, checked for fuel leaks, blew the fuel line from the fuel pump back to the gas tank, replaced the fuel filter,swapped fuel pumps ( mechanical ) swapped another BBD carb I had laying around.
I'm leaning towards not fuel related because I now have a "clear" fuel filter I can see has gas and when the car goes to stall when I pump the throttle under the hood I can see fuel pumping from the "shot" of the fuel enrichment.
Tried an old "orange box" ignition, still won't keep running.

I'm guessing the distributor itself and the pick-up are going to be on my checklist. It too is the cheapest full distributor you can buy from Rock Auto ( I did have points ).
I still have that cheap a$$ china coil on, but I'm quick to dismiss it due to me trying the Pertronix coil with the same results.


I feel like I have to apologize for wasting you guys time, these have all been good ideas, and this WAS a running car before I "fixed" it, so I'm kind of bummed that in an effort to save a few dollars I've caused myself a bit of grief.

I'm going to go to a St. Paddys party today so I'm going to enjoy myself and get back at it later. Thank you all again.
I will update when I figure something out.
 

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My buddy went through same thing and same results. Bought a new unit and no problems. Some of the stuff is crap from the start.
 
Are you saying that it stops running and won't restart? If so, it should be easy to verify whether it loses spark or not.

You said you tried the orange box ignition and it still did it, so that would tend to take the coil and module out of the equation. It would NOT take the wiring from the ignition switch to the ballast and box out of it though.
 
BB73Challenger said:
Tried an old "orange box" ignition, still won't keep running.

I'm guessing the distributor itself and the pick-up are going to be on my checklist.
I feel like I have to apologize for wasting you guys time,
Click to expand...

Sounds to me like this surely must be a distributor problem, but it could be a "weird" defective module. I used to think modules either ran pretty much or not, but at least a couple of guys on here have had Mopars that ran and not well.....turned out to be the ECU

FIRST thing I'd do is check shaft play in the dist. Get a .008" (inches) brass feeler and check the reluctor gap. Check for strike damage and debri in and around the reluctor. Make sure the distributor connector is "made" well.

Make CERTAIN the distributor is hooked via the diagram. Looking at your mount that looks fine

One of the members on here was good enough to "professionalize" my hand drawn diagram. Not which distributor terminal "as drawn" the 'small spade' hooks to. It MUST be this way

attachment.php
 
I am trying to see if the plug wires are interlaced with the pickup wires from distributor, but the picture is not helping. Keep plug wires away from module wiring.

The running and not restarting is likely what Del says, about setting the pickup gap, it is likely too wide. You could also check continuity on the pickup coil when hot, about 350 Ohms. Long ago I found one open, when hot.
 
For your small block, you can buy a complete HEI distributor for $45 on ebay (skip white, etc). For that price, keep one in the trunk or for garage testing. Buy the Harbor Freight in-line spark tester ($4 on sale). Have someone watch it as you try to back out of the garage. If the engine stumbles while the spark is still flashing, it sounds like a fuel problem. Trying shots of starter fluid usually verifies that. I have kept engines running with that when the electric fuel pump seized.
 
...........Doesn't sound like he has a HEI compatible coil or do u not need that?.....or like others say the pick up in the dist........if u have the vac line on the dist unplug it and see what happens.........kim.........
 
oldkimmer said:
...........Doesn't sound like he has a HEI compatible coil or do u not need that?.....or like others say the pick up in the dist........if u have the vac line on the dist unplug it and see what happens.........kim.........
Click to expand...

Before I tore mine down for paint I was simply running the factory Mopar coil. HEI does not seem to be fussy on coils. You CAN get better performance by using an optimal coil with them.
 
67Dart273 said:
... HEI does not seem to be fussy on coils. You CAN get better performance by using an optimal coil with them.
Click to expand...

Mixed results. A factory coil works fine for some. This guy found a Flame Thrower coil didn't work with his HEI module, making internal sparking noises:
www.forabodiesonly.com/mopar/showthread.php?p=1971170753
It probably depends more on the spark plug gap you set, which can be 50-60 mil w/ HEI, if your coil can handle the higher voltage output. e-core type coils are made for that.
 
OK - here's what I have to report...

After sleeping on it, and thinking about how I had cheaped out on the dist and coil, I could only think what's wrong with myself in my head.
So I opted to purchase through Mancini a new distributor. I also opted for one of those advance limiter plates, it's pretty slick.
I also picked up a Delco coil.

So I replace, and double check my connections, and hit the key.
Fires up and dies out... much like I was fighting.

I had just rebuilt my carb 2 years ago, and was not giving it much thought to my problems.
The run condition was a sticking needle :violent1:
It would not let enough fuel in to idle more than a few seconds
Shortly after my flooding was the same issue.
I can't believe it but I had a fresh housing and needle in a drawer.
After airing out the cylinders, checking the oil and replacing my needle/seat the car fires up.

Now spins like a top.
Idles, restarts, cruise and throttle is great.
The mechanical advance limiter plate from FBO seems spot on too.

Thank you all for your continued thoughts and ideas.
I really can't thank you all enough.
 
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