Electronic Ignition Problems

I_am_fishbait · Post by **I_am_fishbait** » September 14, 2009, 12:01 pm

Hey guys I need a little troubleshooting help.
I have a 70 351w in my 62 Uni. I got tired of dealing with the points, so i upgraded the distributer to a late 70's electronic distributor with the standard ole brain box on the fender.
I had the truck running fine and everything was working five out of five. Then life happened and the truck has been sitting for over a year without being cranked. Now I am not getting any fire to the plugs. I have checked most of my connections an power inputs but it is still not firing. The really odd thing is that if you pull the main wire from the middle of the distributor and ground it you can see it fire at the moment you release the key from the start position to the run position. It only fires once ( I am assuming the coil is collapsing) but it does it everytime. I have changed out the brain box to no avail.

Any answers or suggestions ?
Thanks.

clevor347 · Post by **clevor347** » September 14, 2009, 5:00 pm

sounds like a weak coil or a bad pickup coil if these have pickup coils? replaced the pickup coil in my ihc with a pertronix coil thing and eliminated the brain box... runs great and haven't had any problems with it.. I'd try checking the resistance between everything with a meter.

Roger Carter · Post by **Roger Carter** » September 14, 2009, 5:04 pm

I would check out the dist cap and the plug wires. Make sure the cap is free from hairline cracks inside and the the dist and cap are dry. I have seen plug wires break dowm over time, when not being used.
I have also encountered carbs filled with water, from condensation. Make sure that is gas coming out of the carb.
I am sure you have checked for good gas and that all the electrical connections are good, with no corrosion.
I wouldn't think the problem could be anything too serious, since all was fine before you quit driving the truck. Check and double check all the basics and don't assume anything.

Good luck.

Roger Carter

I_am_fishbait · Post by **I_am_fishbait** » September 14, 2009, 5:22 pm

The whole (engine) electrical system from the battery all the way to the spark plug wires are less than two years old. I checked under the dizzy cap and everything looked fine, the coil looks good, and I checked my voltages going to the brain box. The bazaar thing is that it only fires when you release the key from the start position. I know I have got to have more than one little spark to get it going.
The reason I didn't go with one of those spark-tronic kits is that I could get a new dizzy, cap, and the brain box for less than the kit...
I don't know if this will shine some light but I am powering the brain box directly from the start and run posts of the starter solinoid..?

Thanks for the recomendations so far..

62galxe · Post by **62galxe** » September 14, 2009, 6:20 pm

is the coil getting power (small terminal on coil) in the start and run positions on the switch ?

Hawkrod · Post by **Hawkrod** » September 14, 2009, 7:42 pm

I_am_fishbait wrote:The whole (engine) electrical system from the battery all the way to the spark plug wires are less than two years old. I checked under the dizzy cap and everything looked fine, the coil looks good, and I checked my voltages going to the brain box. The bazaar thing is that it only fires when you release the key from the start position. I know I have got to have more than one little spark to get it going.
The reason I didn't go with one of those spark-tronic kits is that I could get a new dizzy, cap, and the brain box for less than the kit...
I don't know if this will shine some light but I am powering the brain box directly from the start and run posts of the starter solinoid..?

Thanks for the recomendations so far..

Uh, a minor point, there is no run position on a solenoid. There is two terminal, one is 12V while cranking (normally the I terminal with a brown wire) and the other is cranking (S terminal with red wire with blue stripe). The I terminal does see voltage while the engine is running but it isn't from the solenoid, it is feedback from the coil. Your 12V while cranking should be connected to the I terminal and your voltage while running should be connected to the ignition switch coil lead. You may be starving your coil and brain box with resistance. Hawkrod

I_am_fishbait · Post by **I_am_fishbait** » September 15, 2009, 12:00 pm

Hawkrod-
I am currently out of town and I am having to visualize what you're saying... I think I got it now. I.. I..

I am pretty sure now that I hooked it up wrong.... I wonder how I got it to run last year then?? But that engine has always started really really easily.
When I get home I will have to switch the wires around and give it whirl.

Thanks

Hawkrod · Post by **Hawkrod** » September 15, 2009, 3:21 pm

I_am_fishbait wrote:Hawkrod-
I am currently out of town and I am having to visualize what you're saying... I think I got it now. I.. I.. I am pretty sure now that I hooked it up wrong.... I wonder how I got it to run last year then?? But that engine has always started really really easily.
When I get home I will have to switch the wires around and give it whirl.

Thanks

When the connections are new and clean you have no problems but any resistance from corrosion/moisture etc... can cause the problems. Hawkrod