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Old 07-13-2018, 11:20 AM   #1
ochre1971
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HEI Questions

I have what I believe to be HEI in my 71, see picture to confirm. I really know very little about these except for the basic function.

While on a moderate road trip over the 4th she failed to start one morning. Cranked over just fine, but sounded like she wasn't getting any fire. I removed the air cleaner and started wiggling wires around at the HEI connection while my wife was cranking, to see if I had just lost contact somewhere. She fired right up at that point.

So, my question is, is there any maintenance I should consider doing to this thing? Are there common problems I should look out for? Anything from the crowd with more knowledge than me, which is an admittedly low bar, that I should be aware of?

Thanks for any input and education.
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Old 07-14-2018, 12:13 AM   #2
1967GTO
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Re: HEI Questions

That is an HEI distributor. I just got one to put in my 72. I wonder if the ignition module was hot and just happened to cool down enough to start. I always had a spare module in my 71 c10. I never had to use it though.
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Old 07-14-2018, 12:46 AM   #3
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Re: HEI Questions

HEI is about as trouble-free as they get. It sounds like you just had a loose connection at the terminal.
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Old 07-14-2018, 06:32 PM   #4
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Re: HEI Questions

I have an HEI in my Jeepster and lost the module as well (same symptoms as you describe) but yours does sound more like a loose wire. That said, the ignition module is pretty cheap and probably worth having a spare in the truck.
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Old 07-14-2018, 09:37 PM   #5
paul mora
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Re: HEI Questions

I have been running a hei with a tuned port injection system for over 15 years. I never use any module except for delco. Believe me I have been through many of them. I continue to have a problem staring my Blazer occasionally. This happens once every three more or every six months over sometimes more often. I found that I have good fuel pressure but it won’t Fire. So just keep a can of staring fluid give a two second blast in the air filter and it start right up. I have replaced parts cleaned injectors and I have found the starting fluid solves my problems and I stopped replaceing parts
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Old 07-14-2018, 09:52 PM   #6
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Re: HEI Questions

Quote:
Originally Posted by paul mora View Post
I have been running a hei with a tuned port injection system for over 15 years. I never use any module except for delco. Believe me I have been through many of them. I continue to have a problem staring my Blazer occasionally. This happens once every three more or every six months over sometimes more often. I found that I have good fuel pressure but it won’t Fire. So just keep a can of staring fluid give a two second blast in the air filter and it start right up. I have replaced parts cleaned injectors and I have found the starting fluid solves my problems and I stopped replaceing parts
If starting fluid gets it going the problem isn't with the HEI. Starting fluid only provides fuel; the spark and timing have to be there for it to do any good.
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Old 07-15-2018, 10:45 AM   #7
paul mora
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Re: HEI Questions

I have always that spark was not the problem and it was fuel. But gone thr throughout the fuel system and all is right. Iwill crank alld ay lone with spark at the plugs. Maybe iit is a weak spark
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Old 07-15-2018, 09:30 PM   #8
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Re: HEI Questions

That is a nice looking rig you have. I blocked a drive thru line for a few minutes a while back when my coil wire decided to go. HEI wouldn't have that coil wire but same concept. Hopefully you just had a wire that disconnected. If it happens again, I would replace the wires
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Old 07-16-2018, 05:54 PM   #9
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Re: HEI Questions

Thanks fellas for the responses and input. Doesn't sound like I should worry about this too much at this point. I'll do some more research and probably go ahead and get a new module to have on-hand. Also, sounds like a good excuse to look into some premium spark plug wires, something I've had somewhere on my list for awhile now anyways.
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Old 07-29-2018, 05:24 PM   #10
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Re: HEI Questions

So, an update. Last week couldn't get her to start at all. My low budget fix of wiggling wires seems to no longer be adequate...
Removed cap and distributor today, replaced the module and coil out of desperation. Scuffed and cleaned all contact points. Got everything put back together and no joy.
I have 12v to the distributor when key is on. Pulled a plug wire and used an old plug to check for spark while being cranked. Nothing.

Any ideas? Is there something else in the hei that I should look at replacing? Anyone had similar experience?
Thanks for any help.

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Old 07-29-2018, 10:37 PM   #11
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Re: HEI Questions

Make sure the center button is in the cap. They sometimes drop out.

And this isn't meant as an insult, but make sure your 12v is going to the BAT terminal.
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Old 07-30-2018, 12:16 AM   #12
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Re: HEI Questions

I had an H.E.I. in my '72 Jimmy that quit working. Changed the module, read about it, cussed it, disassembled, reassembled, still no fire. A friend had a new chineez one in the box, dropped it in and away it went. I paid him $50 & I think they're still pretty cheap on ebay & amazon. Might be an easy fix. Sometimes I can't figure out exactly why electrical stuff won't work & I can live with that.
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Old 07-30-2018, 10:04 AM   #13
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Re: HEI Questions

Thanks, not insulted Truckster. Been doing a lot of reading and watching videos, trying to learn myself up to speed on this thing...
I pulled the red battery wire and hooked a voltmeter to it, showed ~14v with key in ON position.
Rusty, good point. And a frustrating one. With all the reading I've done it seems it isn't uncommon for people to say they had one or multiple dead modules out of the box. So, was that my problem but I fixed it with a bad part? Do I go buy more and keep trying until I definitively mark it off the list? Still trying to figure that out.

Question: The center button / brush, is it supposed to contact the flat metal conductor that is on top of the rotor? Or is the electricity supposed to arc across a gap between the two? You can't see the connection once they are in place, but it doesn't appear they are going to be able to touch each other. The brush is slightly recessed into the rubber grommet that goes under the coil.

Will probably take it all apart again tonight and go through it again. At least stare at it for awhile and have a beer or two. Maybe something will come to me...

For the good news, at least it's conveniently located.
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Old 07-30-2018, 10:14 AM   #14
simicrintz
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Re: HEI Questions

Quote:
Originally Posted by ochre1971 View Post
Question: The center button / brush, is it supposed to contact the flat metal conductor that is on top of the rotor? Or is the electricity supposed to arc across a gap between the two? You can't see the connection once they are in place, but it doesn't appear they are going to be able to touch each other. The brush is slightly recessed into the rubber grommet that goes under the coil.
Pretty sure it touches; don't believe there is supposed to be any gap.
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Old 07-30-2018, 12:58 PM   #15
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Re: HEI Questions

There should be no gap there. You should have a spring under the button.
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Old 08-05-2018, 02:37 PM   #16
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Re: HEI Questions

Another update. I have officially proclaimed myself a hei distributor expert. That, and a dollar should get me a cup of coffee...
Hard to put into words the time, effort, frustration, number of times I've crushed my plums hanging over the front end trying to reach the distributor. Etc.
I bought a new coil. New rotor. New cap. Disassembled the shaft and removed the pickup coil and tested. I can't very well think of any component I haven't removed, tested, held in my hand and wished really hard.
Pondered all night about just buying a whole new distributor assembly. While it should have certainly fixed my issue, I couldn't stand the thought of not knowing what was wrong and ultimately being beaten by this #(+@ thing.
That being said, I went to AutoZone and bought a module. Then went to advanced Auto and bought a module. Then went to pep boys, they had 2 options, a $30 one and a $12 one. I bought both.
All except for the cheapo were BWD brand, made in good ol 'merica. The cheapo was Chinese. You probably know where this is going. The Chinese was the only one to work in my bench test and ultimately in the Blazer.
I wish I could send BWD a bill.
I bought this Blazer several years ago for as much of a hobby as I did too drive it. Guess I got what I wished for, but man is it frustrating to spend so much blood sweat and tears on parts that are rotten out of the box.

I've read about this problem here and elsewhere over the past week or so. Ultimately, I was struggling to believe the problem was really that widespread and continued to test, inspect and retest and reinspect everything multiple times instead of trying multiple modules.

Hopefully someone with the same issue will read this and be quicker than I was to buy multiple modules and multiple brands. Thanks for everyone's help. Going to go drink now.

Tomorrow I'll start researching setting timing, as for all the times I pulled the distributor my timing is now off. Be careful what you wish for.
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