Cant' start Truck. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Lobo'74 · 05-04-2004, 07:26 PM

After driving Truck for 9 months he decided not to start today. Smell gas likes its flooded, but holding the pedal to the floor until it catches didn't work.

I pulled a plug to see about spark and found it looked nasty. A Bosch platinum plug but foulde out in black gunk. 4 of the 8 were like that, 2 were so bad they had the tip covered over. I'm surprised Truck could get going at all. I changed all the plugs (had to pull the passenger side headers to get tho 1 on that side). Got everything back together, still no start.

I've had to crank 2 to 3 short tries to get it started occasionally, but Truck usually starts 1st or 2nd try.

Delco/Remy HEI ignition. My first HEI. . . hate to sound stupid, but I don't see a coil to check, and there are only 8 wires out of the top of the distributer/HEI ignition box.

Edelbrock 1470, 750cfm carb. Its sounds like it is squirtin' gas fine, and you can smell gas after the 5th, or 6th, or 7th . . . start attempt.

I'm clueless. Any ideas on what I can check before I have to get it (shudder) towed to a shop?

Would like to fix it myself rather than take it in, but I need to get it running again. Projects await that need Truck!

Gordo · 05-04-2004, 07:53 PM

Check for spark. Take one of your old spark plugs and attach one of the spark plug wires coming from the dist to it, lay it down some where it can get grounded and have someone crank the engine over while you watch for spark. If none is found, I would suspect the ignition module as long as you have power going into the dist.

cdowns · 05-04-2004, 08:16 PM

when the HEI was installed was a new wire run to it? if using the original wireing you wouldn't have been getting a full 12volts and would cause the module in the HEI to meltdown

Lobo'74 · 05-04-2004, 09:03 PM

Hmmmm.
I don't know. PO rebuilt and installed the '79 350. Which wire would it be? From the battery to the HEI? I need to check and see, but am uncertain as to what I am looking for.

Jeepster376 · 05-04-2004, 09:37 PM

Should be a wire from the unfused ignition circuit on the fuse box to the HEI.

First and foremost check for spark, before you diagnose why you don't have one. use a plug on the block, or what I like to do is stick a timing light on it and see if it flashes.

Cat Fuzz · 05-04-2004, 10:15 PM

I agree with Gordo. I've found that modules go out more than the coil. BTW, the coil sits right on top of the dist. cap under a plastic cover.

Lobo'74 · 05-04-2004, 10:30 PM

Are the modules easily replacable? How do I test the module itself? I still have to go out and check for spark, thats the first thing. If I do not have one it sounds like the next step is to check the ignition module of my Delco-Remy HEI.

Lobo'74 · 05-05-2004, 09:09 AM

No spark. Didn't spark with a plug against the block. Had the induction timing light on another wire, no light.

HEI is a late '70's stock Delco-Remy. Since the engine is a '79 4 bolt main it is either stock, or correct for the time period.

HEI has three wires running from it through the firewall. One each, green, black, red. Green goes to aftermarket tach. Red goes to ignition switch, black is spliced into a different red wire also coming off the back of the ignition switch.

Nothing at all on the fuse block "IGN UNFUSED" location, both lugs empty.

Anyone have any pictures showing the correct wiring diagram for a "stock" late '70's HEI? What is a good publication to see the insides of the HEI? Something like the '67 chassis manual I use would be great.

Thanks for the help so far, and for any more info anyone can provide.

Stanford · 05-05-2004, 11:35 AM

Is the HEI rebuilt, does it have new components in it.

I have had this problem before. Drove to school, and when I left to go home she wouldn't start. It was the module. They are under the cap and rotor and you can take them to your local auto parts dealer and they should be able to test it. For your wiring you need a full twelve volts to the battery plug all the time. If you run a 14 gauge wire from your ignition unfused to the battery plug you'll be fine. The should also be a group of wires coming out of the distributor base, and they are all grouped together and can only go in the cap one way. There is also a ground strap that helps ground out the module and the coil. If thats not in there it will not have spark. I have also seen that the tach plug when plug in, for some reason will take the power away from the coil and want start as well.

Just a few things I have had happen.

Stanford

05-04-2004, 07:26 PM	#1
Lobo'74 Registered User Join Date: Nov 2002 Location: Charlottesville, VA Posts: 404	Cant' start Truck. After driving Truck for 9 months he decided not to start today. Smell gas likes its flooded, but holding the pedal to the floor until it catches didn't work. I pulled a plug to see about spark and found it looked nasty. A Bosch platinum plug but foulde out in black gunk. 4 of the 8 were like that, 2 were so bad they had the tip covered over. I'm surprised Truck could get going at all. I changed all the plugs (had to pull the passenger side headers to get tho 1 on that side). Got everything back together, still no start. I've had to crank 2 to 3 short tries to get it started occasionally, but Truck usually starts 1st or 2nd try. Delco/Remy HEI ignition. My first HEI. . . hate to sound stupid, but I don't see a coil to check, and there are only 8 wires out of the top of the distributer/HEI ignition box. Edelbrock 1470, 750cfm carb. Its sounds like it is squirtin' gas fine, and you can smell gas after the 5th, or 6th, or 7th . . . start attempt. I'm clueless. Any ideas on what I can check before I have to get it (shudder) towed to a shop? Would like to fix it myself rather than take it in, but I need to get it running again. Projects await that need Truck! __________________ "Truck" '67 small window '79 350 .030 over, LT1 "clone"

05-04-2004, 07:53 PM	#2
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	Check for spark. Take one of your old spark plugs and attach one of the spark plug wires coming from the dist to it, lay it down some where it can get grounded and have someone crank the engine over while you watch for spark. If none is found, I would suspect the ignition module as long as you have power going into the dist. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

05-04-2004, 08:16 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	when the HEI was installed was a new wire run to it? if using the original wireing you wouldn't have been getting a full 12volts and would cause the module in the HEI to meltdown __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

05-04-2004, 09:03 PM	#4
Lobo'74 Registered User Join Date: Nov 2002 Location: Charlottesville, VA Posts: 404	Hmmmm. I don't know. PO rebuilt and installed the '79 350. Which wire would it be? From the battery to the HEI? I need to check and see, but am uncertain as to what I am looking for. __________________ "Truck" '67 small window '79 350 .030 over, LT1 "clone"

05-04-2004, 09:37 PM	#5
Jeepster376 Registered User Join Date: Feb 2004 Location: Massachusetts Posts: 269	Should be a wire from the unfused ignition circuit on the fuse box to the HEI. First and foremost check for spark, before you diagnose why you don't have one. use a plug on the block, or what I like to do is stick a timing light on it and see if it flashes. __________________ 72 Cheyenne Super 4x4 SWB

05-04-2004, 10:15 PM	#6
Cat Fuzz My son, my joy. Join Date: Sep 2003 Location: Spokane WA Posts: 463	I agree with Gordo. I've found that modules go out more than the coil. BTW, the coil sits right on top of the dist. cap under a plastic cover.

05-04-2004, 10:30 PM	#7
Lobo'74 Registered User Join Date: Nov 2002 Location: Charlottesville, VA Posts: 404	Are the modules easily replacable? How do I test the module itself? I still have to go out and check for spark, thats the first thing. If I do not have one it sounds like the next step is to check the ignition module of my Delco-Remy HEI. __________________ "Truck" '67 small window '79 350 .030 over, LT1 "clone"

05-05-2004, 09:09 AM	#8
Lobo'74 Registered User Join Date: Nov 2002 Location: Charlottesville, VA Posts: 404	Status so far . . . No spark. Didn't spark with a plug against the block. Had the induction timing light on another wire, no light. HEI is a late '70's stock Delco-Remy. Since the engine is a '79 4 bolt main it is either stock, or correct for the time period. HEI has three wires running from it through the firewall. One each, green, black, red. Green goes to aftermarket tach. Red goes to ignition switch, black is spliced into a different red wire also coming off the back of the ignition switch. Nothing at all on the fuse block "IGN UNFUSED" location, both lugs empty. Anyone have any pictures showing the correct wiring diagram for a "stock" late '70's HEI? What is a good publication to see the insides of the HEI? Something like the '67 chassis manual I use would be great. Thanks for the help so far, and for any more info anyone can provide. __________________ "Truck" '67 small window '79 350 .030 over, LT1 "clone"

05-05-2004, 11:35 AM	#9
Stanford WILLY FOR PRESIDENT!! Join Date: Feb 2004 Location: Wichita, Kansas Posts: 190	Is the HEI rebuilt, does it have new components in it. I have had this problem before. Drove to school, and when I left to go home she wouldn't start. It was the module. They are under the cap and rotor and you can take them to your local auto parts dealer and they should be able to test it. For your wiring you need a full twelve volts to the battery plug all the time. If you run a 14 gauge wire from your ignition unfused to the battery plug you'll be fine. The should also be a group of wires coming out of the distributor base, and they are all grouped together and can only go in the cap one way. There is also a ground strap that helps ground out the module and the coil. If thats not in there it will not have spark. I have also seen that the tach plug when plug in, for some reason will take the power away from the coil and want start as well. Just a few things I have had happen. Stanford __________________ *"He's a high tech REDNECK."* George Jones '67 C/10 FOR SALE!! $600, runs, strait grill, good parts, or beater truck '68 GMC K25, 4x4, current project '71 Custom/10, Crate 350, My Baby!! '97 Pontiac Grand Prix GTP



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