HEI question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

boundstaffpress · 05-17-2008, 09:36 PM

When replacing the coil in my HEI cap, I don't have a wire that goes from the ground on the coil to the ground terminal for the module. The coil just grounds to itself.

Is this a problem?

**michael bustamante** · 05-17-2008, 09:49 PM

I believe coil grounds when you run the hold down screws, but its been awhile since I opened my cap

BarryB · 05-17-2008, 10:03 PM

You have three wires coming out of the dis, and go to the coil, I am pretty sure the coils grounds itself thru the control module. It has to complete the circuit in order for the module to work. That's my thoughts for what there worth.

Wrenchbender Ret · 05-17-2008, 11:32 PM

There is a terminal that goes under the coil to the center term on the connector where the dist plugs in. Some early models used a wire. This is often left out when someone replaces the cap. It must be there or serious component failure will occur.

LONGHAIR · 05-18-2008, 03:15 AM

Yes, you need that.
I really have no clue as to why someone would leave it out, but they do. Apparently it will run (at least for a while) with out it, but I have never seen it. Every one I ever worked on was because it wouldn't start.

old Chevy guy · 05-18-2008, 05:38 AM

After putting a new intake gasket on one of the many chevy vans Ive had I put a new cap ,wires and plugs in. Without realizing I left that little ground strap between the coil and the plug out. The van ran but when I
test drove it it didnt seem to run quite right so I drove past the driveway and drove it further in the other direction,all at about 2 in the morning on a work night. Well when I went to turn around again the truck stalled and would not start again,I tried until the battery was dead. It turned out to be the darkest night ever,me without I light,broke down next to the cematary 2 miles from home 230 am.It was so dark I could only find my way by following but barely seeing the yellow lines in the center of the road.Where I live there are few street lamps ,mostly only at corners,and the houses are few and far between!Needless to say when changing a HEI cap I never forgot that ground again! By the way it started right up and was fine when I fixed the ground in the daylight the next day

jhow66 · 05-18-2008, 06:57 AM

The ground strap looks like this:

boundstaffpress · 05-18-2008, 07:04 AM

Thanks guys.

Are these available at checker/napa?

:Edit: They are. Just found them here.

**El Jay** · 05-18-2008, 11:22 AM

Quote:

Originally Posted by old Chevy guy

After putting a new intake gasket on one of the many chevy vans Ive had I put a new cap ,wires and plugs in. Without realizing I left that little ground strap between the coil and the plug out. The van ran but when I
test drove it it didnt seem to run quite right so I drove past the driveway and drove it further in the other direction,all at about 2 in the morning on a work night. Well when I went to turn around again the truck stalled and would not start again,I tried until the battery was dead. It turned out to be the darkest night ever,me without I light,broke down next to the cematary 2 miles from home 230 am.It was so dark I could only find my way by following but barely seeing the yellow lines in the center of the road.Where I live there are few street lamps ,mostly only at corners,and the houses are few and far between!Needless to say when changing a HEI cap I never forgot that ground again! By the way it started right up and was fine when I fixed the ground in the daylight the next day

Did you "whistle past the graveyard?"

LONGHAIR · 05-18-2008, 03:32 PM

It has been years since I worked on one with the ground missing, but I don't remember one starting by just putting the ground back on. I seem to remember it always killing something else. Module? coil?

boundstaffpress · 05-18-2008, 05:18 PM

I lost a coil. It may have been from old wires and rusty coil support, but I suspect that I have also lost my module now. I have a new one. I should have just bought a whole new skip white unit in the beginning.

LONGHAIR · 05-18-2008, 05:32 PM

That's a live-and-learn thing. From what I have heard, his stuff is great, and the cost difference would be minimal. Oh well, next time

boundstaffpress · 05-18-2008, 10:22 PM

I ended up making a ground, as they were out at the parts store, and the salvage yard was not open.

I did get the engine to fire up, but I still have a weak spark on #5, #7 and #2. May have to order some new plugs.

05-17-2008, 09:36 PM	#1
boundstaffpress Jamie Hyneman is my twin Join Date: Nov 2005 Location: La Junta, Colorado Posts: 705	HEI question When replacing the coil in my HEI cap, I don't have a wire that goes from the ground on the coil to the ground terminal for the module. The coil just grounds to itself. Is this a problem? __________________ Justin SOLD 1967 K10 Fleetside, 283, Front and Rear Posi SOLD Color Wiring Diagrams Now in High Resolution V8 and Cab and Cab and Chassis

05-17-2008, 10:03 PM	#3
BarryB Senior Member Join Date: Jul 2006 Location: Blountville, Tn. Posts: 3,904	Re: HEI question You have three wires coming out of the dis, and go to the coil, I am pretty sure the coils grounds itself thru the control module. It has to complete the circuit in order for the module to work. That's my thoughts for what there worth. __________________ We could learn a lot from crayons... Some are sharp; some are pretty;and some are dull. Some have weird names; and all are different colours;but they all have to live in the same box. You may be only one person in the world, But you may also be the world to one person. * Some mistakes are too much fun to only make once. Two rules in life. 1. Never sweat the small stuff! 2. Everything is small stuff! Last edited by BarryB; 05-17-2008 at 10:03 PM.

05-17-2008, 11:32 PM	#4
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: HEI question There is a terminal that goes under the coil to the center term on the connector where the dist plugs in. Some early models used a wire. This is often left out when someone replaces the cap. It must be there or serious component failure will occur.

05-18-2008, 05:38 AM	#6
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: HEI question After putting a new intake gasket on one of the many chevy vans Ive had I put a new cap ,wires and plugs in. Without realizing I left that little ground strap between the coil and the plug out. The van ran but when I test drove it it didnt seem to run quite right so I drove past the driveway and drove it further in the other direction,all at about 2 in the morning on a work night. Well when I went to turn around again the truck stalled and would not start again,I tried until the battery was dead. It turned out to be the darkest night ever,me without I light,broke down next to the cematary 2 miles from home 230 am.It was so dark I could only find my way by following but barely seeing the yellow lines in the center of the road.Where I live there are few street lamps ,mostly only at corners,and the houses are few and far between!Needless to say when changing a HEI cap I never forgot that ground again! By the way it started right up and was fine when I fixed the ground in the daylight the next day

05-18-2008, 07:04 AM	#8
boundstaffpress Jamie Hyneman is my twin Join Date: Nov 2005 Location: La Junta, Colorado Posts: 705	Re: HEI question Thanks guys. Are these available at checker/napa? :Edit: They are. Just found them here. __________________ Justin SOLD 1967 K10 Fleetside, 283, Front and Rear Posi SOLD Color Wiring Diagrams Now in High Resolution V8 and Cab and Cab and Chassis Last edited by boundstaffpress; 05-18-2008 at 07:11 AM.

05-17-2008, 09:49 PM	#2
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,873	Re: HEI question I believe coil grounds when you run the hold down screws, but its been awhile since I opened my cap __________________ 1967custom

05-18-2008, 03:15 AM	#5
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	Re: HEI question Yes, you need that. I really have no clue as to why someone would leave it out, but they do. Apparently it will run (at least for a while) with out it, but I have never seen it. Every one I ever worked on was because it wouldn't start.

05-18-2008, 06:57 AM	#7
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Re: HEI question The ground strap looks like this: Attached Images __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

05-18-2008, 03:32 PM	#10
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	Re: HEI question It has been years since I worked on one with the ground missing, but I don't remember one starting by just putting the ground back on. I seem to remember it always killing something else. Module? coil?

05-18-2008, 05:18 PM	#11
boundstaffpress Jamie Hyneman is my twin Join Date: Nov 2005 Location: La Junta, Colorado Posts: 705	Re: HEI question I lost a coil. It may have been from old wires and rusty coil support, but I suspect that I have also lost my module now. I have a new one. I should have just bought a whole new skip white unit in the beginning. __________________ Justin SOLD 1967 K10 Fleetside, 283, Front and Rear Posi SOLD Color Wiring Diagrams Now in High Resolution V8 and Cab and Cab and Chassis

05-18-2008, 05:32 PM	#12
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	Re: HEI question That's a live-and-learn thing. From what I have heard, his stuff is great, and the cost difference would be minimal. Oh well, next time

05-18-2008, 10:22 PM	#13
boundstaffpress Jamie Hyneman is my twin Join Date: Nov 2005 Location: La Junta, Colorado Posts: 705	Re: HEI question I ended up making a ground, as they were out at the parts store, and the salvage yard was not open. I did get the engine to fire up, but I still have a weak spark on #5, #7 and #2. May have to order some new plugs. __________________ Justin SOLD 1967 K10 Fleetside, 283, Front and Rear Posi SOLD Color Wiring Diagrams Now in High Resolution V8 and Cab and Cab and Chassis Last edited by boundstaffpress; 05-18-2008 at 10:24 PM.



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