Need a quality US Made HEI recommendation for my 250 I6
 

Well, from the research I've done it sounds like my HEI module or something in my HEI system on my late 70's i6 250 might be going. I'm not sure what company of HEI to go with but don't want cheap off shore stuff, preferably US made quality. Don't need performance but something to replace the stock set up for trouble free driving.

My truck runs great, starts awesome but while driving I have a very rare and very intermittent stall or buck like someone shut the key off real quick then back on.(it's not a fuel issue, too quick, no sputter) Sometimes the engine kicks back on right away and other times it stalls instantly while I'm on the gas heavy or light. When it stalls, I coast a bit and it always starts right back up like nothing happened. Very odd but I need it to be reliable and figured I might as well just replace the entire HEI which is now probably 40 = years old..

Can someone recommend a quality HEI set up, Cheers

Re: Need a quality US Made HEI recommendation for my 250 I6
 

I think DUI is still made in America

Re: Need a quality US Made HEI recommendation for my 250 I6
 

I think when I need one I will buy a rebuilt or remanufactured one, or send mine to somebody to get it rebuilt. I'm just tired of Chinese stuff that works for a little while then falls apart.

I don't know if these are the right people, but I bookmarked them a while back and they may be worth a call. http://philbingroup.com/rebuilt/distributors.htm
Their website is kind of cruddy and has broken links, but I see they have a phone number to call. They don't seem to have crazy prices. I'm not endorsing them, just suggesting you be our test animal and let us know how it goes. :-)

The problem with your HEI may be in the wiring that powers it. Maybe you have a corroded connection or wire, or maybe the coil is giving up.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

>>The problem with your HEI may be in the wiring that powers it.<<

I agree, but it could be the pickup coil wires in the HEI that are constantly flexing with the vacuum advance. It doesn't sound like a module problem.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Rebuilt / Re-manufactured GM
Paul Jr @ GMCPauls

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Find out what needs fixed on your good old USA made by GM distributor and fix it.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

OP

did your truck come with a HEI dizzy or was it originally a points dizzy truck?

if the later than the resistance wire needs to be replaced with a 10 gauge stranded wire

I have Pertronix module in 2 of my classic car/trucks using the stock points dizzy. Just swap out the resistance wire.

If you have the white cloth covered wire coming out of your bulkhead connector...you still have the resistance wire which needs to be replaced

Your issue may be more coil and or wiring

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Before you waste the family fortune buying another distributor, consider this.
Your running symptoms indicate a cold carb and intake.
Is your heat riser valve working?

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Thanks to everyone for the replies, very much appreciated! So I guess I should try to troubleshoot a bit before I go and shotgun the whole system. Please forgive my lack of knowledge on this stuff, a couple months back I had no clue what an HEI distributor even was! Lol

So, all I know history wise of this engine is the PO blew up the original 250 ci and found a later GMC truck 250 and put it in then the truck sat for 7 years. When I bought the truck, it would only idle and stall out if revved up. After a carb rebuild and a gas tank clean me and my Dad realized the choke had no mechanism for opening up when the engine got warm. This makes me believe the PO never got to drive the truck with the new engine, got frustrated cause it wouldn't run right with a constant full choke and sold it.

I've attached a bunch of pics of the distributor, not sure if it's original to the mid to late 70's GMC engine though.. Looks like the harness has been spliced several times, is the resistance wire the one that starts out yellow then has a bunch of butt connectors leading into the distributor? There's no way the original yellow wire from the harness is 10 gauge. How far back would that yellow wire go under the electrical tape do you think?

My electrical diagnosing skills are minimal but I'm not scared to replace any wiring as long as I know what to remove and redo. I have extensive soldering skills from building guitars amps.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

I originally thought it my be the engine starved for fuel as well but have played around with the choke when this happens and it doesn't matter where the choke is, on or off ( I have a manual choke now). The symptoms are very instant and abrupt when it stalls, it kinda bucks once and the engine instantly dies like the key was turned off. If the engine doesn't die, it's kind of like a random buck then back to normal driving. Very weird..

I've attached pics of the heat riser valve, not sure how to test it. Is it just spring operated and the spring closes on it's own when warm?

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Heat riser is under the carb. Parts are a flapper valve, bimetallic spring type coil and a counter weight.
Take a pic under the carb where the exhaust pipe is.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Info here.


http://67-72chevytrucks.com/vboard/s...d.php?t=313227

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Just measure the DCV with engine running, on that yellow spliced into red wire going into dizzy. It should readd 12vdc when running.

if it reads around 9...than that wire still has the white braided resistance wire in it between bulkhead connector and dizzy.

There is another thread here showing a new braided wire IIRC cost that OP around $8 to replace the entire wire from bulkhead connector. It comes with the male terminal for bulkhead connector attached and bare end at other that would, in your case, connect to dizzy since you have a coil in cap HEI. For external coil you just run that wire to + terminal of coil.

You can easily make your own new wire if needed. Those spade terminals are available at places like Del City

Typicallly when HEI module fails it's instant shut off, usually when engine is at operating temp. Sometimes when cool the motor will restart.

Your issue may be something else like wiring or fuel delivery issue

I can't see in your pics if vacuum advance is hooked up...it should be. Without it you can experience stumbling issues accelerating as no more timing is being brought in. It won't cause your engine to shut off though

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Ok I'll check the voltage while running. If it is only giving the 9v power using the old wire, would that cause the issues I'm experiencing?

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Here's a pic of the flapper under the carb. It seems to move nice and free and bounce back with the spring. Anything else I should check with that?

Re: Need a quality US Made HEI recommendation for my 250 I6
 

HEI dizzy and Pertronix modules require 12vdc vs the points using around 9vdc so they don't burn up quick. 9vdc will kill a HEI module

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Should be good as long as someone hasn’t removed the flapper inside.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

My experience is that modules either work or they don't. Plus it is usually something else such as a high resistance in the secondary that kills them.

Take a real close look at the wires where they connect to the terminals and coil end on the pickup coil. I had that proven to me back in the late 70's when they were still pretty new. Even when they were only 3 years old those wires were failing at the conection.

The Napa Echlin module or other ign parts used to be good but who know who makes them now.

I'd trust the Accel 35361 but they aren't cheap. I've never had an issue with Accel ign parts.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

OP

You might want to un tape the wiring harness that yellow wire to dizzy is in to see if it has any more splices and with the ones using butt crimp connectors..remove those and solder the wires together first putting heat shrink on one wire first to cover the solder connections.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

I agree, it probably is the pickup coil like Richards photo. It is not hard to replace but you have to pull the shaft out to do it. The shaft usually has some varnish on it & doesn't want to come out. Spray some carb cleaner around it at the bottom & it will come on out. This isa good time to clean up & grease the mechanical advance mech. & check the vacuum advance. That is a good unit. Don't replace it with an aftermarket dist.

George

Re: Need a quality US Made HEI recommendation for my 250 I6
 

>>It should readd 12vdc when running.

if it reads around 9...than that wire still has the in it between bulkhead connector<<

>>HEI dizzy and Pertronix modules require 12vdc vs the points using around 9vdc so they don't burn up quick. 9vdc will kill a HEI module<<

72SB, none of that is true.

If you remove the resistance wire, you should have 14 volts.
You should be within a couple tenths of the battery voltage, which should be close to 14 volts if the alternator is charging close to normal.

I have had my '67 since 1985 and for the last 33 years it has had an HEI powered with that white braided resistance wire still in place. Originally it had a coil-in-cap HEI as pictured in this thread. When I installed AC about 15 years ago, I installed an HEI with external coil for clearance under the compressor.

The white braided resistance wire (ballast resistor) will drop the voltage about 2 volts, but since you are actually starting with 14 volts, you should measure 12 volts at the HEI. If I recall, the last time I measured the voltage at my external HEI coil, it measured 11.8 volts and at the time, my alternator was going out. I haven't had reason to recheck it.

>>9vdc will kill a HEI <<. If that were true, anyone that has had a dead battery would have surely killed their HEI.

I experienced a CS130 alternator failure in my Corvette that had an HEI.
I drove 50 miles home with the BAT light ON and the instrument VM showing under 12 volts. It wasn't until the VM showed 8.5 volts that the engine began to sputter. It did not die, it sputtered into my driveway.

Over voltage can kill an HEI as well as many other automotive electronics. The Pertronics I , mentioned in this thread are very susceptible to any voltage close to 16 volts.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Just put a Dui in my brother's 235

Also worth mentioning new set of wires really woke up the 454 in our old blue.

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Unfortunately you are wrong. Believe what you want. External ballast and resistor wires are for points dizzy.

Pertronix specifically says in any of their units to eliminate resistor wire if converting over to points. There are several threads on this forum about replacing the resistor wire for HEI be it a GM unit or Pertronix. Read up

Agreed lower voltage will not "immediately" kill a HEI module...but it will after time

Re: Need a quality US Made HEI recommendation for my 250 I6
 

The module can go lickity split with low voltage. I had two go up on me in a row. Like the replacement lasted a day or two. I looked farther and found that both wires into the distributor had oxidized green showing almost at the distributor. The insulation had cracked, and this was on a rebuilt HEI I paid good money for. I grabbed that harness off a junk truck I had and that fixed it and kept it going forever. It's true, either a module works or it doesn't... crank crank crank crank was the symptom

Re: Need a quality US Made HEI recommendation for my 250 I6
 

Do you know where I could get a quality pickup coil like that? Is that more of a specialty part or would most parts stores have that?