V8 HEI Installed Issues ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

54blackhornet · 04-05-2022, 05:32 PM

I installed a original GM HEI last summer on my 307. Ran great after I hooked up everything.Yesterday I started it up and it ran horrible. Pulled the plugs to find them dry but pretty black so I figured it was the 2 Barrel Rochester until I noticed that the distributor cap was not completely secured, only one of the spring clamps was on properly. Do these work loose or did I not get them on properly ?

CantPutTheSmokeBack · 04-05-2022, 05:47 PM

It's pretty easy to think you've got them seated, just for them to come undone. Picked up several cars in the past that had one or two loose/unseated. Just give it another shot.

**C101972** · 04-05-2022, 05:55 PM

The cap sits in a slot, you can tell when it’s in the proper location. When you fasten it, if you feel under the ledge of the distributor where the hold downs are. They also have a slot that holds the four of them in place. Also you might want to take a peak inside the cap, because when it was running rough the rotor could have possibly gouge inside of it. Good luck! Thanks Chuck
Posted via Mobile Device

54blackhornet · 04-05-2022, 06:41 PM

Thanks fellas ! I just tightened them up but now the engine will not fire ? Will pull the cap and check the rotor and underneath the cap.

**'68OrangeSunshine** · 04-05-2022, 07:14 PM

If you have a spare module, try that.

CantPutTheSmokeBack · 04-05-2022, 07:27 PM

I got into the habit of, when changing the cap and rotor, forgetting to install the rotor. Also, make sure it's plugged in. If it is, make sure you've got power. Easy to overlook the small things.

bry593 · 04-06-2022, 11:54 AM

Quit buying Chinese distributors and you won't have any problems.

**LockDoc** · 04-06-2022, 12:53 PM

Quote:

Originally Posted by bry593

Quit buying Chinese distributors and you won't have any problems.

This isn't really helpful.... Not cool.

Did you even read his original post?

LockDoc

BigBird05 · 04-06-2022, 07:52 PM

Dito LockDoc

54blackhornet · 04-08-2022, 01:36 PM

Follow up ! Original GM HEI , off a 75 C/10 finely died.

**C101972** · 04-08-2022, 01:56 PM

Unless you are trying to stay pretty much OE, go to Summit Racing and purchase a MSD HEI distributor. They are easily to install and are a breeze for recurving your timing advance. If you can find the right person to setup, you will have more power and better fuel economy. Thanks Chuck
Posted via Mobile Device

54blackhornet · 04-08-2022, 02:27 PM

Thanks Chuck for the suggestion !….Jack

**hatzie** · 04-10-2022, 01:24 PM

There's no reason to replace an HEI distributor.
You can completely rebuild your original HEI distributor on your work bench in a few hours.
As long as the advance weight pins or the shaft aren't worn past serviceability they're easily rebuildable.

Page down to post #4 in this thread where I posted a fairly decent howto on rebuilding the coil in cap HEI distributors with some links to more.
http://67-72chevytrucks.com/vboard/s...d.php?t=765779

If the pigtail harness from the module to the cap looks the least bit gnarly just replace it with an AC Delco D221 HEI pigtail & Condenser. If you're running the original condenser it's likely reached the end of its useful lifespan. Electrolytic capacitors usually only last a three decades or so. The goobers selling this part on Amazon call it a radio antenna module capacitor...

Pay attention to the driven gear end play with the body and the proper placement of the shims.

**Warrens69GMC** · 04-10-2022, 02:22 PM

Did you run a new 12v source to the HEI?

Or did you run the existing wire?

conoco · 04-10-2022, 03:37 PM

Quote:

Originally Posted by 54blackhornet

I installed a original GM HEI last summer on my 307. Ran great after I hooked up everything.Yesterday I started it up and it ran horrible. Pulled the plugs to find them dry but pretty black so I figured it was the 2 Barrel Rochester until I noticed that the distributor cap was not completely secured, only one of the spring clamps was on properly. Do these work loose or did I not get them on properly ?

I recently had the same issue with my GM HEI. I ended up buying a new coil after replacing my spark plugs and wires. I wasn't getting any spark. Took me a while to figure out why. Long story short it was the coil.

Just throwing this out there but I recently replaced my hei with a Progression Ignition HEI. I could not be happier. This thing is awesome and my truck runs so much smoother. There are some guys on this forum that helped me out a lot while I figured out the different timing table to play with. Best purchase I have made for my 72 beside my gear vendors unit. Plus its made in the USA and I will always pay a little more for a product in country Good luck brother!

https://progressionignition.com/

KQQL IT · 04-10-2022, 05:07 PM

My latest HEI fail

54blackhornet · 04-10-2022, 06:11 PM

Again thanks everyone for your input. This pickup never ventures off my property, just used to bring firewood in from my wood lot. It sits quietly from October/November until the snow goes away. I can’t justify sinking a lot of cash into that awesome electronic control distributor but I appreciate your suggestion. After looking inside the GM HEI I decided not to rebuild it because it sat outside before I got it and it’s corroded badly. I have another one in much better condition lined up….will keep you updated on my progress..Jack

04-05-2022, 05:32 PM	#1
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,393	V8 HEI Installed Issues ? I installed a original GM HEI last summer on my 307. Ran great after I hooked up everything.Yesterday I started it up and it ran horrible. Pulled the plugs to find them dry but pretty black so I figured it was the 2 Barrel Rochester until I noticed that the distributor cap was not completely secured, only one of the spring clamps was on properly. Do these work loose or did I not get them on properly ? __________________ 71 C-20 07 Magnum RT AWD

04-05-2022, 05:47 PM	#2
CantPutTheSmokeBack Registered User Join Date: Mar 2022 Location: Erin, TN Posts: 46	Re: V8 HEI Installed Issues ? It's pretty easy to think you've got them seated, just for them to come undone. Picked up several cars in the past that had one or two loose/unseated. Just give it another shot.

04-05-2022, 05:55 PM	#3
C101972 Senior Member Join Date: Jan 2021 Location: Saint Cloud, Minnesota Posts: 539	Re: V8 HEI Installed Issues ? The cap sits in a slot, you can tell when it’s in the proper location. When you fasten it, if you feel under the ledge of the distributor where the hold downs are. They also have a slot that holds the four of them in place. Also you might want to take a peak inside the cap, because when it was running rough the rotor could have possibly gouge inside of it. Good luck! Thanks Chuck Posted via Mobile Device

04-05-2022, 07:14 PM	#5
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,512	Re: V8 HEI Installed Issues ? If you have a spare module, try that. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

04-05-2022, 07:27 PM	#6
CantPutTheSmokeBack Registered User Join Date: Mar 2022 Location: Erin, TN Posts: 46	Re: V8 HEI Installed Issues ? I got into the habit of, when changing the cap and rotor, forgetting to install the rotor. Also, make sure it's plugged in. If it is, make sure you've got power. Easy to overlook the small things.

04-05-2022, 06:41 PM	#4
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,393	Re: V8 HEI Installed Issues ? Thanks fellas ! I just tightened them up but now the engine will not fire ? Will pull the cap and check the rotor and underneath the cap. __________________ 71 C-20 07 Magnum RT AWD

04-06-2022, 11:54 AM	#7
bry593 Registered User Join Date: May 2016 Location: Oklahoma Posts: 201	Re: V8 HEI Installed Issues ? Quit buying Chinese distributors and you won't have any problems. __________________ 1971 C20 Custom Deluxe, HT383, 4L80E, 3.73 Locker, 4 Wheel Discs

04-06-2022, 07:52 PM	#9
BigBird05 Registered User Join Date: Aug 2019 Location: Cheraw Posts: 1,300	Re: V8 HEI Installed Issues ? Dito LockDoc

04-08-2022, 01:36 PM	#10
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,393	Re: V8 HEI Installed Issues ? Follow up ! Original GM HEI , off a 75 C/10 finely died. __________________ 71 C-20 07 Magnum RT AWD

04-08-2022, 01:56 PM	#11
C101972 Senior Member Join Date: Jan 2021 Location: Saint Cloud, Minnesota Posts: 539	Re: V8 HEI Installed Issues ? Unless you are trying to stay pretty much OE, go to Summit Racing and purchase a MSD HEI distributor. They are easily to install and are a breeze for recurving your timing advance. If you can find the right person to setup, you will have more power and better fuel economy. Thanks Chuck Posted via Mobile Device

04-08-2022, 02:27 PM	#12
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,393	Re: V8 HEI Installed Issues ? Thanks Chuck for the suggestion !….Jack __________________ 71 C-20 07 Magnum RT AWD

04-10-2022, 01:24 PM	#13
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: V8 HEI Installed Issues ? There's no reason to replace an HEI distributor. You can completely rebuild your original HEI distributor on your work bench in a few hours. As long as the advance weight pins or the shaft aren't worn past serviceability they're easily rebuildable. Page down to post #4 in this thread where I posted a fairly decent howto on rebuilding the coil in cap HEI distributors with some links to more. http://67-72chevytrucks.com/vboard/s...d.php?t=765779 If the pigtail harness from the module to the cap looks the least bit gnarly just replace it with an AC Delco D221 HEI pigtail & Condenser. If you're running the original condenser it's likely reached the end of its useful lifespan. Electrolytic capacitors usually only last a three decades or so. The goobers selling this part on Amazon call it a radio antenna module capacitor... Pay attention to the driven gear end play with the body and the proper placement of the shims. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

04-10-2022, 02:22 PM	#14
Warrens69GMC Registered User Join Date: Jan 2003 Location: Safford,AZ Posts: 3,625	Re: V8 HEI Installed Issues ? Did you run a new 12v source to the HEI? Or did you run the existing wire? __________________ 1969 307, t350 1950 Chevy Wagon 1978 Big 10 1967 C10, 250,3-OTT

04-10-2022, 05:07 PM	#16
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,260	Re: V8 HEI Installed Issues ? My latest HEI fail Attached Images __________________ " That didnt make it any newer " " Dont antique the equipment "

04-10-2022, 06:11 PM	#17
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,393	Re: V8 HEI Installed Issues ? Again thanks everyone for your input. This pickup never ventures off my property, just used to bring firewood in from my wood lot. It sits quietly from October/November until the snow goes away. I can’t justify sinking a lot of cash into that awesome electronic control distributor but I appreciate your suggestion. After looking inside the GM HEI I decided not to rebuild it because it sat outside before I got it and it’s corroded badly. I have another one in much better condition lined up….will keep you updated on my progress..Jack __________________ 71 C-20 07 Magnum RT AWD



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