IGNITION PROB... THE FINAL FRONTIER. help!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

redz 1970 K5 · 03-17-2005, 01:25 PM

So, when I was pulling the old distributor and wires, I was like baahh, child's play, I can get it back together and didn't pay close attention to the wire routing.

I dropped the new distributor, hooked up the ignition module and the 12v, and ran new plugs and wires.

She cranked, but would not fire. Fuel is definitely getting into the cylinders, so it is definitely ignition. I got the engine set to TDC, made sure the rotor was pointing to cylinder 1, and I confirmed I have around 10 volts to the Distributor. This is how my wires are routed now-

Now, after checking more things, I looked at the old cap. It's routing is like this-

All manuals say the above pic is the norm, but my old routing is different. Since it ran, I am suspecting I need to run the wiring and reset the distributor pointing to 1 at TDC and try again...

Can anyone shed light on this? It's a 74 engine.

71jimmy · 03-17-2005, 01:46 PM

Sorry, All I have is the manual for the 71Jimmy, not HEI, but shows wiring as in pic 1, first pic. Do you have spark? You probably did this already but unplug spark plug wire from cyl one spark plug, hold wire just above the plug and have someone crank, should see a spark arcing from the wire to the plug. May need to put a bolt into the end of the wire to extend out of the boot and have it somewhat dark in the garage. I ussually hold the wire with a pair of insulated pliers, so I don't get that tingle in my arm when she cranks.

jhow66 · 03-17-2005, 01:47 PM

Did you changed from points to HEI ? If so the 1st diagram is the one to use. The 2nd one is how a points dist. was wired. You will need to retime your dist. so that rotor is pointing to #1 @ TDC in 1st diagram.

redz 1970 K5 · 03-17-2005, 01:56 PM

I swapped an old OEM HEI dizzy for a new aftermarket HEI dizzy. No kidding, the old HEI was wired as in pic 2. That's why I am confused.

Last night, I set TDC and retimed the dizzy to insure the rotor was pointing to position 1 on the Cap already ( as in pic 1).

Far as checking for spark, couldn't I just use an inductive timing light hooked up to the wire, and see if the strobe flashes when someone cranks it over?

redz 1970 K5 · 03-17-2005, 02:31 PM

Ok, did some more research. Something changed between 1974 and 1975 on HEI plug wire routing- that #1 position did change between those years... I cross referenced this to confirm, and am 99% sure that pic 2 is the correct routing for my truck.

Of course, can't it be said that as long as the firing order is correct, and that plug 1 corresponds to cylinder 1 at TDC that it will run? So plug 1 can be in any location? Or is there something in the ignition that requires a specific routing?

WEIRD...

*72CSTC5* · 03-17-2005, 03:19 PM

Bring your number 1 cylinder to top dead center and make sure you stab the distributor so that your rotor is pointing there and then start wiring according to which diagram you use. I've never heard of the firing order changing on an HEI distributor. New to me.

redz 1970 K5 · 03-17-2005, 03:28 PM

The firing order didn't change, just the location of the wires... I am sure I can use either pic 1 or 2 , so long as #1 is at TDC.

But, thanks everyone for the help. Any more troubleshooting tips would be appreciated.

71jimmy · 03-17-2005, 03:36 PM

Well, if you insist on doing it the easy way I suppose hooking your timing light up would work. I however always do things the hardest way humanly possible, gives me an excuse why I didn't finish. LOL

redz 1970 K5 · 03-17-2005, 03:44 PM

HAHA!

She's coming out of the garage tonight or tomorrow morning, either under her own power or mine... I can do the rest of the work in the driveway at this point.

vtblazer · 03-17-2005, 06:56 PM

I know it's obvious but it hadn't been mentioned.
TDC, yes of course but make sure it's on the [compression stroke]
I'm sure you did but just checking.

redz 1970 K5 · 03-17-2005, 07:17 PM

Yup, I crank the crank cwise while my finger is over the #1 plug hole. As soon as I start to feel a push of air, I just continue to crank the engine over until the mark on the h-balancer lines up with the timing marker at 0 Degrees.

jostrans68 · 03-17-2005, 09:18 PM

how did you wire power up it should not be 10 volts should be 12 did you run a new wire for power? if you connected to old yellow wire that may be problem

**VetteVet** · 03-17-2005, 11:21 PM

Not trying to be a smartazz or questioning your ability but you did use the drivers side front cylinder as no. 1 and not the passenger side.
VetteVet

redz 1970 K5 · 03-18-2005, 04:38 AM

So, after some more troubleshooting, it ended up being the splice to the HEI ignition; it is spliced into the pink wire from the firewall, it is a 12V switched source. I started at the coil and started tracing back... Voltage was correct on the truck side of the splice, but low on the HEI lead... Just removed the splice, soldered and shrink wrapped the joint, and voila 11.8 volts.

Hooked up the timing light, cranked a few times (it was like 11:30 PM with open headers, so I couldn't start her), but the strobe of my timing light was strobing, and I know my wires are setup right, so all signs point to go tomorrow AM.

70 shorty · 03-17-2005, 11:24 PM

I also noticed the 10 volts mentioned. You should be getting a full 12 volts at the distributor for an HEI to work properly.

**pjmoreland** · 03-18-2005, 12:05 AM

The original ignition wire that runs from the connector on the firewall is some special type of wire that has high resistance to drop the voltage. The yellow wire from the starter motor temporarily raises the voltage to 12 volts while the engine is cranking. I installed an HEI distributor in my truck a while ago. I got rid of the original ignition wire and the yellow wire from the starter motor. I ran a wire from the fuse panel through the firewall to the distributor.

If you hook up a timing light and have an assistant crank the engine over, you can check to make sure your timing is correct.

Longhorn Man · 03-18-2005, 12:36 AM

#1 can be anywhere you put it. In all reality, it doesn't matter where it is. Bring the engine to TDC...then back it about 8 degrees. Stab the dist into the hole and make sure you get the oil pump in the grove...if you can clamp it dowm then it's good.
Pop the rotor on there. Where ever the end of the rotor is, is now #1. I usually mark the base of the dist exactly in line with the end of the rotor.
Now clamp the cap onto the dist. Locate the mark on the side of the dist body. If it is directly under a spark plug wire tower, then wire it 1843....ect.
If it is not directly under a wire tower, then rotate the dist untill it is.
Then wire it.
Asuming you have it at TDC on compression, like you indicated, then it'll fire right up as soon as you hit the key.
The 10 volts you are reading...your battery is probably weak. Dome light on, crankin the crap out of it...listing to some tunes...ect. The resistance wire woulda cut it down lower than 10, so if it'll crank, then you'll be OK on that.

crispy · 03-18-2005, 09:50 AM

first off, i just wanna say good luck Redz. obviously, we're all pulling for you. secondly i wanna say that this thread is awsome for information and just plain old troubleshooting ideas. thanks everybody

busterwivell · 03-18-2005, 12:47 PM

And.............????

I'm sure you're havin' too much fun now with it runnin' and all. TELL US!

You gonna be at DelMar?

03-17-2005, 01:46 PM	#2
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,084	Sorry, All I have is the manual for the 71Jimmy, not HEI, but shows wiring as in pic 1, first pic. Do you have spark? You probably did this already but unplug spark plug wire from cyl one spark plug, hold wire just above the plug and have someone crank, should see a spark arcing from the wire to the plug. May need to put a bolt into the end of the wire to extend out of the boot and have it somewhat dark in the garage. I ussually hold the wire with a pair of insulated pliers, so I don't get that tingle in my arm when she cranks. __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

03-17-2005, 01:47 PM	#3
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Did you changed from points to HEI ? If so the 1st diagram is the one to use. The 2nd one is how a points dist. was wired. You will need to retime your dist. so that rotor is pointing to #1 @ TDC in 1st diagram. __________________ 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

03-17-2005, 01:56 PM	#4
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	I swapped an old OEM HEI dizzy for a new aftermarket HEI dizzy. No kidding, the old HEI was wired as in pic 2. That's why I am confused. Last night, I set TDC and retimed the dizzy to insure the rotor was pointing to position 1 on the Cap already ( as in pic 1). Far as checking for spark, couldn't I just use an inductive timing light hooked up to the wire, and see if the strobe flashes when someone cranks it over? __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 02:31 PM	#5
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	Ok, did some more research. Something changed between 1974 and 1975 on HEI plug wire routing- that #1 position did change between those years... I cross referenced this to confirm, and am 99% sure that pic 2 is the correct routing for my truck. Of course, can't it be said that as long as the firing order is correct, and that plug 1 corresponds to cylinder 1 at TDC that it will run? So plug 1 can be in any location? Or is there something in the ignition that requires a specific routing? WEIRD... __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more Last edited by redz 1970 K5; 03-17-2005 at 02:57 PM.

03-17-2005, 03:28 PM	#7
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	The firing order didn't change, just the location of the wires... I am sure I can use either pic 1 or 2 , so long as #1 is at TDC. But, thanks everyone for the help. Any more troubleshooting tips would be appreciated. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 01:25 PM	#1
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	IGNITION PROB... THE FINAL FRONTIER. help!! So, when I was pulling the old distributor and wires, I was like baahh, child's play, I can get it back together and didn't pay close attention to the wire routing. I dropped the new distributor, hooked up the ignition module and the 12v, and ran new plugs and wires. She cranked, but would not fire. Fuel is definitely getting into the cylinders, so it is definitely ignition. I got the engine set to TDC, made sure the rotor was pointing to cylinder 1, and I confirmed I have around 10 volts to the Distributor. This is how my wires are routed now- Now, after checking more things, I looked at the old cap. It's routing is like this- All manuals say the above pic is the norm, but my old routing is different. Since it ran, I am suspecting I need to run the wiring and reset the distributor pointing to 1 at TDC and try again... Can anyone shed light on this? It's a 74 engine. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 03:19 PM	#6
72CSTC5 Account Suspended Join Date: Nov 2004 Location: Deer Park, Tx. Posts: 2,524	Bring your number 1 cylinder to top dead center and make sure you stab the distributor so that your rotor is pointing there and then start wiring according to which diagram you use. I've never heard of the firing order changing on an HEI distributor. New to me.

03-17-2005, 03:36 PM	#8
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,084	Well, if you insist on doing it the easy way I suppose hooking your timing light up would work. I however always do things the hardest way humanly possible, gives me an excuse why I didn't finish. LOL __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

03-17-2005, 03:44 PM	#9
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	HAHA! She's coming out of the garage tonight or tomorrow morning, either under her own power or mine... I can do the rest of the work in the driveway at this point. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 06:56 PM	#10
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	I know it's obvious but it hadn't been mentioned. TDC, yes of course but make sure it's on the [compression stroke] I'm sure you did but just checking.

03-17-2005, 07:17 PM	#11
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	Yup, I crank the crank cwise while my finger is over the #1 plug hole. As soon as I start to feel a push of air, I just continue to crank the engine over until the mark on the h-balancer lines up with the timing marker at 0 Degrees. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 09:18 PM	#12
jostrans68 Jostrans68 Join Date: Mar 2001 Location: Bloomington indiana Posts: 1,182	how did you wire power up it should not be 10 volts should be 12 did you run a new wire for power? if you connected to old yellow wire that may be problem __________________ [CGTW Member former 67-72 now with a 96 silverado

03-17-2005, 11:21 PM	#13
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Not trying to be a smartazz or questioning your ability but you did use the drivers side front cylinder as no. 1 and not the passenger side. VetteVet __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

03-18-2005, 04:38 AM	#14
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	So, after some more troubleshooting, it ended up being the splice to the HEI ignition; it is spliced into the pink wire from the firewall, it is a 12V switched source. I started at the coil and started tracing back... Voltage was correct on the truck side of the splice, but low on the HEI lead... Just removed the splice, soldered and shrink wrapped the joint, and voila 11.8 volts. Hooked up the timing light, cranked a few times (it was like 11:30 PM with open headers, so I couldn't start her), but the strobe of my timing light was strobing, and I know my wires are setup right, so all signs point to go tomorrow AM. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

03-17-2005, 11:24 PM	#15
70 shorty Where's my beer? Join Date: Oct 2004 Location: Glen Allen, VA Posts: 1,772	I also noticed the 10 volts mentioned. You should be getting a full 12 volts at the distributor for an HEI to work properly. __________________ 70 C10, shortstep, .30 over 250,Hurst shifted 3 spd parts hauler. Holley 390, Clifford Intake, Header, ported cylinder head, unknown bigger cam. 79 Corvette L82, 4 spd, black, red interior, headers, flowmasters, and unkown bigger cam. '03 Grand Cherokee Laredo, 4.0 4x4 daily driver. 165K miles, and runs great '08 Tahoe LTZ 4x4 155K



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03-18-2005, 12:05 AM	#16
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,773	The original ignition wire that runs from the connector on the firewall is some special type of wire that has high resistance to drop the voltage. The yellow wire from the starter motor temporarily raises the voltage to 12 volts while the engine is cranking. I installed an HEI distributor in my truck a while ago. I got rid of the original ignition wire and the yellow wire from the starter motor. I ran a wire from the fuse panel through the firewall to the distributor. If you hook up a timing light and have an assistant crank the engine over, you can check to make sure your timing is correct.

03-18-2005, 12:36 AM	#17
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	#1 can be anywhere you put it. In all reality, it doesn't matter where it is. Bring the engine to TDC...then back it about 8 degrees. Stab the dist into the hole and make sure you get the oil pump in the grove...if you can clamp it dowm then it's good. Pop the rotor on there. Where ever the end of the rotor is, is now #1. I usually mark the base of the dist exactly in line with the end of the rotor. Now clamp the cap onto the dist. Locate the mark on the side of the dist body. If it is directly under a spark plug wire tower, then wire it 1843....ect. If it is not directly under a wire tower, then rotate the dist untill it is. Then wire it. Asuming you have it at TDC on compression, like you indicated, then it'll fire right up as soon as you hit the key. The 10 volts you are reading...your battery is probably weak. Dome light on, crankin the crap out of it...listing to some tunes...ect. The resistance wire woulda cut it down lower than 10, so if it'll crank, then you'll be OK on that.

03-18-2005, 09:50 AM	#18
crispy '71 Chevy Blazer Join Date: Jan 2005 Location: San Leandro, CA (near Oakland) Posts: 96	first off, i just wanna say good luck Redz. obviously, we're all pulling for you. secondly i wanna say that this thread is awsome for information and just plain old troubleshooting ideas. thanks everybody __________________ '71 K5 Blazer (new project / daily driver) "If you are not working to improve the situation, you have no business complaining"

03-18-2005, 12:47 PM	#19
busterwivell Registered User Join Date: Jan 2002 Location: Sahuarita, AZ USA Posts: 2,033	And.............???? I'm sure you're havin' too much fun now with it runnin' and all. TELL US! You gonna be at DelMar? __________________ Bill - Tucson, AZ 47 Chevrolet 2 dr sedan 56 Chevrolet 210 2 dr sedan 66 Chevrolet Malibu 2 dr 4 speed 71 Chevrolet C30 Longhorn 86 Chevrolet Monte Carlo SS (Sold) 01 Chevrolet Tahoe IM - BUSTERWIVE@aol.com

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