tinner

I started working on my '69 Cutlass again. Went to start it....no spark ( I am assuming a bad control module because I do have power to the distributor). Anyway, it had been converted to an HEI before I got the car. It is wired from the IGN spade at the fuse block (which powers on/off at the ignition switch). The wire appears to be pretty light gauge, so I am going to increase that. Is anyone putting an inline fuse in this wire? If so what amp fuse? Also, the car has an external regulator. I read that this set up is hard on modules. Is this true? The car had run when I put it away last fall. Could it have been caused by the regulator, the light gauge "hot" ignition wire, or just plain old Murphy's law?? This HEI has less than 500 miles on it. Any input would be great.

henryk8398

Hmm. I've never heard of needing a fuse on the HEI coil wire. I've also never heard of externally regulated alternators causing a problem for HEIs. Not saying it isn't possible, but I would do some more research on that. As long as you're getting the full 12v, it should be ok. As far as the wire to the coil, try 10 gauge.

My next steps would be some basic troubleshooting as far as the coil, pickup, etc. You might want to get the module tested. Also, check all the wiring to the distributor. Any chance a rodent could have gotten into it?

Rickman48

Recently, on a couple other threads, it's been the dialectic grease under the module causing bad grounds.
Check 'em out!

tinner

Wires are good as far as that goes. I pulled the module out to get it tested. I actually found the post on the Regulator in the Wiki section. I hadn't heard of before either, but I didn't know if I missed something on that one. I will check voltage, but wire is direct from fuse block. Too much Dialectric grease? Never heard that one either....is this even after they had run? Thanks

oldcutlass

Does your 69 have a start circuit from the starter to the dist? If so make sure you are getting 12v to the hei while cranking.

MDchanic

Me neither.
In fact, you don't want a fuse there. You'd rather have a running problem that makes you pull over than have a fuse blow at 80mph on the highway.
Who came up with the regulator idea, and what was his explanation?

... And, to be clear to readers, dielectric grease is insulating grease that is NOT supposed to go under the module - it's for spark plug boots.
The stuff that goes under the module is heat sink paste, which is a completely different thing.

- Eric

oddball

If the ext regulator is the mechanical type, it can cause lots of electrical noise. Add in 40+ year old chokes (capacitors) not quite up to snuf, and life can be hard on sensitive electronics.

MDchanic

Okay, I'll go along with the theory, but have you seen it in practice?
(ie: a car that "eats" HEI modules, but stops doing it when changed to an electronic regulator).

- Eric

oldcutlass

The only problem I have ever encountered with a mechanical regulator and an HEI failure, is over/ or under voltage due to malfunction or maladjustment.

tinner

Here's what I had seen in the wiki search regarding the regulator... This is the quote...
"Electronically Regulated Alternator: You must convert to a electronically regulated (non-vibrating regulator) alternator. Converting externally regulated GM alternators (pre 1971) to internally regulated post-71 alternators is a relativly easy affair. You will be burning out HEI modules at record pace if this is not done!
I took a look at the mechanical regulator and I could see how it would give my HEI a hard time, causing it to fail shorty after installation. One set of points in the regulator is eaten up pretty bad, and it turns out the regulator was causing some problems with dim lights, and what appeared to be generally low battery voltage. When I started the car after installing the new regulator the ammeter indicated about a 25 amp charge. The mechanical regulator was not correctly sensing the battery's charge.
My '71 had the mechanical regulator stock from the factory. However, my Olds Service Manual indicates some cars of that year had the solid-state regulators in the alternator. To check, if you see a black box above the distributor about 3" square on the firewall you likely have a mechanical regulator. I say, "likely," because some replacement, aftermarket regulators are made now that install in the same location and look the similar but have solid-state, electronic guts."

MDchanic

What's your source for that, Tinner?

Looks like he said that he had a bad regulator that was giving him a low voltage, which, as OldCutlass suggested, can be hard on HEI modules. If your voltage is okay, that shouldn't be a problem.

He says that when he started the car with the new regulator, it charged at 25A. That's about what any car I've ever had with an ammeter has charged at, after a normal start, so I'm not sure what he's getting at.

As I say, I have never heard of (properly operating) mechanical regulators burning out HEI modules, but I am glad to change my mind if anyone on this forum has had any actual experience with it.

As far as the action of mechanical regulators goes, yes, there is a vibratory component to the opening and closing of the points, but the power supply in a car, especially an older car, is far from a clean DC waveform - the output of the alternator is not carefully smoothed, and all the regulator does, mechanical or electronic, is to regulate the current through the rotor, which regulates the output voltage. Considering the constantly-changing AC output (changing both in frequency and voltage) of the alternator, rectified by the output diodes to full-wave pulsed DC, I doubt that the mechanical regulator is doing much to pollute that waveform.

- Eric

tinner

MDchanic, I did a search on the site for converting to HEI distributor. I found it and was able to paste it this time. The info I found is (when you scroll down on the link) right under the Ohm test schematics. Had my ignition module tested today...turned out good. Time to check the coil I guess.


http://www.oldsmobilewiki.com/index....ion_Conversion

MDchanic

Well, if you've got no spark at all, and the module's good, that leaves the Hall effect sensor, the power source, the coil, the connections to the coil, the connections to the module (wires pinched and shorting under module retaining screws), and the coil wire (possibly leaking to ground if it's old).

I'd take a good close look at everything and see if you can see anything bad before buying any parts. Do you have any friends with HEI who might swap coils with you to see if that's your problem?

- Eric

tinner

I can pull the coil off of my Monte & give that a shot. The car drove into it's spot in the barn in fall. It's strange that it's not popping now. I have to check volts, but power is right off of the fuse block...I'd assume I would have 12 volts.

MDchanic

Well, y'know what happens when you make an "assumption"... "You" and "'Mption."

I'd check the voltage. The spade lug on the fuse block is not the best place to draw power from (tapping directly into the pink wire from the ignition switch is more direct).

- Eric

Run to Rund

Back in 1975, Olds engineering sent me two HEIs to "test" on my 66 W30 which of course had the external regulator. I ran 12V starting and running to the HEI, and had no issues.

tinner

It was the power source. I got it fired off, but I think I will tap into that pink wire. Thanks again!

MDchanic

Ah HA!!

- Eric

tinner

Yeah Yeah It sure was good to listen to it run again. I still have alot of "bugs" to work out.

Sugar Bear

In the HEI link you provided a resistor is mentioned that decreases voltage to prevent burning the points while the car is running. I believe the resistor is actually the thin gauge wire that goes to the factory non-HEI ignition coil, it is a special wire that is pink in color if I recall correctly. Some cars also had a yellow wire going from the coil to the starter solenoid wire that would supply full battery voltage only when the solenoid was closed during engine cranking to help the starting process. When the solenoid opened it would feed from the resistor pink wire at the lower voltage.

If you can look at a car that has factory HEI, the power supply wire to the distributor will still be pink but heavier gauge.

When checking voltage on the original pink wire it has to be measured when there is current flowing to get the voltage drop so if the key is on and the car is not running, measuring at a loose wire end would read full battery voltage. The voltage will drop when current/amperage flows.

I think that when using the original wire the voltage to the HEI will be too low when running and this could damage a module. Look at how a factory HEI setup is wired and do it that way. Can someone on the forum please chime in as to whether or not there is a higher primary current draw with HEI and whether or not the older ignition switches can handle the increased load or are the older switches still ok to use? Of this I am not sure.

Hope this helps.

MDchanic

You are entirely correct, Bear, though, truth be told, the same has come up a number of times here, and is frequently restated.

As far as current draw, I have never heard of HEI overloading an ignition switch, and, in fact, the switches on the (roughly) '69 to '75 cars are the same.

- Eric

Sugar Bear

MD

Would you know if the advance curves are similar between HEI and the earlier distributors? Are the weights and springs interchangeable to keep the same advance rates?

Thanks!

MDchanic

No and No.

There has been discussion here on the differences in the advance curve, but I can't recall where just now. If my mind is working, then the HEI has a shorter range than the points unit, in other words, you have to set the HEI further advanced (higher number) at idle in order to obtain the desired 34-36° totat at about 3,200 RPM.
There are others who are experts on this, though.

Essentially, if you've got an HEI distributor on an early or modified motor, you will get some improvement if you install an aftermarket tunable weight kit and adjustable vacuum diaphragm.

And I believe the Olds weights are different from Chebbie weights, because the Olds distributor turns counterclockwise.

- Eric

oldcutlass

Also your spark plug gap needs to be .045 with an HEI. Do not use the resistor wire.

The easiest way to set your timing is to run the engine up to 32-3400 rpm (or where ever it stops advancing) and set your timing at 34-36* with vacuum advance disconnected. Then check where your initial falls at curb idle.

With vacuum advance connected you want to see your total advance somewhere at around 50* +/- at 34-3600 RPM. If your sense any detonation back off 2* and test again, repeat until it goes away!

droldsmorland

To add my .02 to this post... Several vendors offer a solid state external regulator. It physically looks and mounts the same. In fact you can put an original Delco cover on it and only a well trained eye will know the difference. My points style reg would constantly hang up for some reason. I replaced it with several new units and they all hung-up and would keep the GEN light lit until the reg unlatched, several seconds after the key was off. The solid state solved that prob.
I'm running one with an original alternator, DUI, HEI. 8mm Taylor spiral cores and Autolites gapped at .040"(.045s ok too I just prefer .040 with the tips ground 1/2 way back).
I did have to customize the advance curve, as the out-of-the-box curve was off for my 11:1, 400. Initial is set at 12*, Adjustable vac can adds another 10*...now were at 22ish. The rest is all in at 2800-3000rpms for a total of aprox 40-42* FYI; you can mix and match springs to obtain your custom curve. Most think they need to use the springs in matched sets. The best most accurate way to get your curve dead-on is to know your Cam, Converter, rear gear, and tire diameter. Then send your distributor along with that info to someone who has a SUN distributor machine. I have performed this myself and with a SUN curve machine, The SUN is more accurate and it takes hours of guess work out of the equation.

MDchanic

Why not?

It's not a race car, and the HEI has plenty of power to spark through resistor wires. If he uses solid wires, he may end up with radio interference, and also, aren't solid wires a speed-shop item for these systems, and therefore a lot more expensive?

If you mean, "Don't use both resistor wires and resistor plugs together," I could see that, since you only need one or the other, but HEI was designed to fire through resistor wire, and there should be no noticeable difference in operation between the two.

- Eric

coppercutlass

I thought the resistor wire dropped voltage to keep the points alive and the hei needs constant 12.

MDchanic

Absolutely true.

Oh crap. You meant the resistor FEED wire.

I though you meant resistor SPARK PLUG wires.

D'oh.

Never mind.

- Eric

oldcutlass

Pay attention! LOL

We will let you off easy this time!! Yes, he will need a different set of spark plug wires, the HEI requires 8mm. But I assumed he already knew this!