No spark, any suggestions?

[Tynee]

The HEI in my '70 isn't throwing a spark. I drove it home from work on Monday, commented to my wife how well it ran after I replaced the fuel pump last weekend, then jumped in it Tuesday after work to run some errands, and it wouldn't even try to start.

Took the module to O'reilly, it tested good, replaced the capacitor and distributor cap with known good ones that I had in the shed. Still no spark. Any suggestions?

[ChevLoRay]

Mine did something similar, but the wire to the pick-up coil in the HEI had a break in it that would cause an open circuit when I let off of the gas and the vacuum advance moved the "breaker" plate.

After I replaced the old HEI with a new Accel HEI, no more problems.

[texanidiot25]

I'd test the ign wire and make sure it's hot when the key is on. If the Dizzy is mechanically sound, that'd be my guess.

[soba_03]

If it's got HEI I'd check the carbon button that contacts the top of the rotor. I've had them just vanish...LOL. it's something simple to check. Let us know what you find.

Good luck..

[68gmsee]

I used these sites to check mine out some time ago. Make sure you have a good ground (clean) connection at the base to the frame. Also, if you converted to HEI from points, insure you are using a non resistive wire to the distributor. If you used the old wire, it may work but can damage the module. Make sure you are using the dielectric grease on the module.

http://www.granitecityperformance.co...&print=1&page=

Testing the GM HEI Distributor
A no-spark condition is checked by checking the distributor for power at the connector on the side of the cap. If there is power, disconnect the electrical connector and remove the cap. Check the rotor and the cap for excessive wear. Check the coil tower for excessive wear. Remove the top plastic cap on the distributor cap. Use an ohmmeter and check the coil positive terminal to the metal case of the coil. The reading should be infinity. Check the coil tower and the negative terminal. The reading should be 900 ohms. Check the positive terminal to the negative terminal. The reading should be around 700 ohms. If any of these tests show drastically different readings, the coil is bad. If the coil is good, the cap and rotor are not cracked or worn significantly and there is no spark at any wire, replace the ignition module.

[maddog1331]

Originally Posted by texanidiot25

I'd test the ign wire and make sure it's hot when the key is on. If the Dizzy is mechanically sound, that'd be my guess.

What Texanidiot said I fixed a friends truck that had the same problem some time back. It had been running fine, one day it just wouldnt start. The ignition wire looked fine but it had a complete break in it. It looked factory (truck was an 80 model or some such) and the outside of the wire looked fine, but the actial wire inside was extremely brittle.

EDIT: By the way Tynee, Hiya neighbor! I didn't realize there was anyone near Somerset on the board!

[Tynee]

Hey maddog, there are indeed several members from the general area. There used to be a post where all of the kentuckians checked in. Might run a search for Kentucky. There's actually a member in or very close to Somerset named Junkyardjohn. Moved to Somerset from Las Vegas, NV a few years ago. I was as close to you as Russel Springs the other day on my way to my grandparents' house in Edmonton.

Anyway, I've pretty well narrowed it down to a the coil pickup being the most likely culprit. My question is, how do I get it out from under the mechanical advance assembly?

I'm looking real hard at just replacing the entire Dizzy. It's filthy in there, even some rust from an unknown source. When I look around, I' ve found an ACCELL HEI on CL that's supposed to be almost brand new, for $80, or I can replace the coil pickup in my current unit for $40. I'm leaning towards the ACCEL unit.

[Sinister]

Skip White HEI on E-Bay is another option.

[VetteVet]

This may be helpful:http://www.rustpuppy.org/ignition2/Ignition%202b.htm

[Tynee]

Originally Posted by VetteVet

This may be helpful:http://www.rustpuppy.org/ignition2/Ignition%202b.htm

That's good info, thx.

[68gmsee]

I used the rustpuppy site to rebuild mine and also this site-

http://rmcavoy.freeshell.org/HEI.html

If you scroll down, he gives pn's for the items you may need.

One thing I will caution you on. If the shaft is pretty much dried up or caked up with gunk and won't budge, don't force it out. Let it soak with a solvent agent or whatever you use for degreasing and slowly work the shaft out.

I forced mine and moved the upper bearing. I was able to tap it back down, though.

[maddog1331]

Originally Posted by Tynee

Hey maddog, there are indeed several members from the general area. There used to be a post where all of the kentuckians checked in. Might run a search for Kentucky. There's actually a member in or very close to Somerset named Junkyardjohn. Moved to Somerset from Las Vegas, NV a few years ago. I was as close to you as Russel Springs the other day on my way to my grandparents' house in Edmonton.

Anyway, I've pretty well narrowed it down to a the coil pickup being the most likely culprit. My question is, how do I get it out from under the mechanical advance assembly?

I'm looking real hard at just replacing the entire Dizzy. It's filthy in there, even some rust from an unknown source. When I look around, I' ve found an ACCELL HEI on CL that's supposed to be almost brand new, for $80, or I can replace the coil pickup in my current unit for $40. I'm leaning towards the ACCEL unit.

Hey, thanks for the info! I did a search and realized there were quite a few Kentucky members, it is good to know Maybe this summer a bunch of us can all go participate in the Somernites Cruise one weekend or something. My truck isn't by any means a show truck, but any excuse to take her up and down the road is a good one!