Help with no spark please

[conoco]

I had my truck in the garage all winter why I replaced the rockets. I pulled it out last week and it fired up right away. Took if for a drive and it ran great. Now I try to start it and it turns over really strong but has no spark.

I replaced the entire distributor
I replaced all the spark plug wires
I replaced all the spark plugs
Replaced the alternator.

I put a new ground cable from the battery to the block.

I have no idea what else to do but I am super frustrated. Can anyone help me out or give me things to check or replace that might fix it. All the other wiring works good. I just dont understand how it fired right up and drove great and now nothing. Thank u

[geezer#99]

What distributor is it?

[conoco]

It had 5 stars and people seemed to like it. Everything I researched on it said it was good too.

[geezer#99]

Do you have a dedicated 12v power supply hooked to it?
Pull the connection off the distributor and check for 12v with key on.

[conoco]

It has power to the red and yellow wires off the distributor with my test light. Would you know what setting I need to put it on to check for volts with this multimeter?

[conoco]

I figured it put. It says I have 12.38 volts coming from the red wire I checked it at the exposed area on top

[57taskforce]

You can also test it by running a wire straight from the battery positive to the positive terminal of the distributor. If it starts you know you’ve got a power issue feeding the distributor. Beware you won’t be able to kill it while wired like this unless you pull the wire off the battery. You need to have 12v going to the distributor while it’s cranking and while the key is in the run position. Sounds like maybe the cranking portion of that circuit at least is not working.

[Sheepdip]

I hate coincidences but they do happen, and seems like to me more than anyone.

Check to see if you got 12 volt power to the distributor while cranking it over.

Could be you ignition switch went south also.

[conoco]

While I am cranking it with the volt meter it goes to 0. Should it do that?

[BigBird05]

You need at least 12v while cranking it over to start. Run a test wire from the battery to the + side of the dist. (one that can be disconnected to shut off the engine ) It should start. If it does you need to find out why you don't have 12v from the ign. switch when you are cranking the truck over.

[Sheepdip]

Originally Posted by conoco

While I am cranking it with the volt meter it goes to 0. Should it do that?

Nope....your ignition switch is bad. Quick double check with a jumper wire from your battery +12 volt to your distributor +12 volt crank it over and should fire right up.

[conoco]

It still won't fire. It does go to 10 volts with the jumper while I am cranking it though.

[RustyPile]

Originally Posted by conoco

It still won't fire. It does go to 10 volts with the jumper while I am cranking it though.

If you ran a jumper from the battery positive to the "BATT" terminal on the distributor and it still won't fire, The problem is NOT the ignition cylinder, NSS, starter, nor anything related to them.. The problem is inside the distributor.. With it being a new unit, don't go digging in it trying to find the problem.. Take it back and get another distributor...

I'm wondering why you replaced the alternator because of a "no run" condition??

[57taskforce]

red cap racing power made me laugh for some reason. That’s your problem right there. Like I said above gotta have power cranking and in the run position.

[57taskforce]

What’s the voltage on the battery while the key is off

[conoco]

Brand new batter read 12.35. I have dual batteries can I hook them together and try?

[conoco]

I think the last thing left to replace is the ignition cylinder. I will pick one up tomorrow. Starting to get super frustrated and disappointed. It ran so good and now nothing.

[tim_mc]

I had a year-old ACDelco HEI go out on me just a few weeks ago. A new coil and module from Advance Auto Parts did the trick. I've since upgraded to Davis Unified Ignition 50K coil and their module. Runs even better now! The USA-made module from Advance is now in the glovebox as a spare.

Frankly, I'd avoid distributors with no-name labels (Yicton?) or appear to be made in China. I've read that there is a large production run of HEI distributors that are known to be defective and are being resold online.

[tim_mc]

Here is an awesome HEI troubleshooting guide I used by WIDESIDE72 on this site:
http://67-72chevytrucks.com/vboard/s...d.php?t=645976

[Luvlegs]

Any chance you went from points distributor to the electronic dizzy? Meaning you changed the resistance wire out?

[Fbks_Cruiser]

I’ve heard good things about Davis Unified (DUI). I suspect that cheap distributor has other problems too.When I change out mine I’m gonna go with a DUI distributor. Granted it cost more at $285 but worth it to not have made in China.

If your getting power to the distributor in run and start positions the ignition switch isn’t the problem. Also you said you ran a jumper wire from battery to the distributor which also eliminates the ignition switch power source as the problem.

[tim_mc]

Originally Posted by Fbks_Cruiser

I’ve heard good things about Davis Unified (DUI). I suspect that cheap distributor has other problems too.When I change out mine I’m gonna go with a DUI distributor. Granted it cost more at $285 but worth it to not have made in China.

Amen to that. My GM HEI was made in Taiwan, if I recall correctly. One reason I wanted it was for its melonized gear since I was installing roller cam. I thought a GM distributor would be solid, but I guess not now that I've replaced the coil and module in about a year. DUI is based in Memphis:
https://performancedistributors.com/

While on the subject, here's a handy spark checker I picked up from Harbor Freight for only $3.99 - a lot cheaper than the parts stores.
https://www.harborfreight.com/90-in-...ker-63593.html

[conoco]

I pulled the ignition switch to replace it just because I had already bought it. This is what I found. I really hope this is the problem. Anyone know the best way to attach a new pig tail? I just dont understand how everything went from running awesome to having this burnt out. Like I said, not sure if this will fix everything but I hope it does and will let u all know. Thanks very much for everyone's suggestions on this.

[Sheepdip]

Originally Posted by conoco

I pulled the ignition switch to replace it just because I had already bought it. This is what I found. I really hope this is the problem. Anyone know the best way to attach a new pig tail? I just dont understand how everything went from running awesome to having this burnt out. Like I said, not sure if this will fix everything but I hope it does and will let u all know. Thanks very much for everyone's suggestions on this.

I just put these on mine earlier this year

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[conoco]

Well even with the original pig tail obviously melted I put the new one in and still have no spark..I want to burn my truck to the ground at this point.ill try to double check everything I already have when I fly back home next Monday..This is killing me. If anyone has any other ideas I am all ears..thanks fellas