Re: Help with no spark please
 

How did you determine there is no spark?

Re: Help with no spark please
 

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

Re: Help with no spark please
 

It had HEI when I bought the truck and just stayed with hei when I swapped.

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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

Re: Help with no spark please
 

When you say, "no spark", are you using that term in a general sense to mean the engine isn't starting, or did you physically confirm that the spark plugs are not sparking by using a spark checker, timing light, etc?

Re: Help with no spark please
 

I pulled the number 1 spark plug and grounded it to the engine block and I have no spark. I also held it about .25 inches away and still nothing. I just bought a spark plug tester but had to fly back to work and didn't have time to use it. I will check when I get back. Just hope I can get it running so I can go on my fishing trip next weekend.

Was I checking for spark incorrectly? I always thought to just pull the number 1 plug from the engine, leave it attached to the spark plug wire and ground it to the engine. Maybe I did it wrong.

Re: Help with no spark please
 

Had a similar situation . Was going to put new valve cover gaskets on the 72 . Went and washed the engine at the local car wash had the engine running and it stalled got in no start. Did all the usual things sprayed inside the cap with wd40 wipped it out sprayed all the wires checked every connection at the distributor. Got a test light no juice to the distributor. The po had put in the HEI and used a fuse in line . Well the water shorted the wire a blew the fuze 30 minutes for a 10 cent fuse.

Re: Help with no spark please
 

Sounds good.

Re: Help with no spark please
 

Man I hope at this point it is that easy of a fix. I have installed alot of new parts this week lol. I will check when I get home and trace the line. If I cant get it going when I get back I am taking it to the shop after I test everything I already have 1 more time. Maybe my perspective will change a little and I will find what the heck is going on. I will say prior to this happening last week my truck was running outstanding.

Re: Help with no spark please
 

I've been thinking about your problem. If I understand, you had the same issue with the old distributor. You said you are getting power at the Batt terminal on the distributor. Exactly where are you putting the test probe of your multimeter to check that? The reason I ask is that you may have a faulty connection plugging the power wire into the distributor. Did the previous owner use an actual HEI pigtail like the first picture or is it just a crimped on connector like the second picture? I have seen it before where those generic crimped female connectors miss the terminal inside the distributor and although there is power at the connector it is not making good contact to the distributor.

Re: Help with no spark please
 

Mine look like the two of those combined. The picture you have of the red a green all as one piece. I have that same connector but instead of them being combined, they have two separate plugs. I also don't have red and green wires. My battery wire is a thick yellow wire and the tach wire is a smaller red wire. Both plugs I believe have the same grooves as the one in your picture. The yellow one has that little spin that goes down the middle of the plug to I think lock it in place. The red one has the open section on the plug like the one you show.

I did by a new pig tail off amazon. its only 6 bucks so it's not breaking the bank. When I get home I am going to follow both those wire from the back of the distributor and see if they are fried anywhere. Obviously something happened because when I posted the pic of my ignition switch the plug was melted a little bit on the top red wires. Maybe something else is fried also. I will change out the plug and see if that helps anything.

I am testing for power doing the following.
Key in the ON position.
Test light probe touching the bat and tach side with the distro cap removed. Both of them the light will come on when touched.

Re: Help with no spark please
 

Okay. I'm a little concerned that you are seeing power on the tach terminal. Not sure if that is correct. Someone more knowledgeable than I can chime in on that.

As for the plug on the distributor, not trying to be condescending, but is there a chance it is put in backwards? Being two pieces I don't know if it is possible. I'm thinking that could maybe be the cause of the melted terminal on the back of the ignition switch. In the attached image, the red wire is the+12V (color not important). What is important is the tang you can just make out on the backside of the plug in this image. It slides into a groove in the distributor to ensure the plug can only go in one way. The +12V terminal on the distributor is the one closest to the firewall.
Unless you have a tach, the other wire doesn't need to be connected. Since you have a 2 piece plug, I would leave that terminal disconnected just to eliminate one more potential problem.

Oh, also is the ground strap inside the distributor in place?

Re: Help with no spark please
 

They are as you described . My yellow wire has the tang and goes closest to me. My red is by the firewall. I have a tach which is stock in my truck and it does work. Has since I got it. Your not being condescending at all. Wouldn't be the first time I didn't see something small as to the source of an issue. My plugs only go in one way though just like the 1 piece plug you attached. I am assume the Tach wire has power when I put the test light on because it goes from the tach spot on my distributor, then plugs into one side of my tach and then there is another wire on the other side of my tach that plugs into my fuse panel.

Re: Help with no spark please
 

I'm confused. I thought you said your yellow wire is the battery +12V. That should be going to the terminal closet to the firewall as per the picture of the distributor.

PM sent if you wanna call me.

Re: Help with no spark please
 

Your right. My thinker wire of the two is the yellow wire, but it is plugged into the slot where the yellow wire above goes in the picture above. The Red wire goes to the red position but it is not as thick as the yellow wire. I would say that might be the problem but I have been driving my truck for almost 2 years and it has been running great. maybe that is why the ignition switch finally burnt out. I don't know. I will trace the yellow and red wires when I get home and let you know where they both go. I would love to take you up on that phone call next week when I fly home if I cant get this figured out.

Re: Help with no spark please
 

Sure, call anytime. I'll be out of phone service June 25-July 5 (taking a friends boat from Bellingham, WA up to Juneau) Aside from that, I'm free.

Re: Help with no spark please
 

This is the set up I took out and the original when I bought it. worked great up until last week.

Re: Help with no spark please
 

I suggest trace where the yellow and red wires actually go. Find out exactly where they connect in the cab and verify they don't connect to some other wire on the way to the cab, for example you don't want the power wire connecting to a white cloth covered wire in the engine wire bundle. The white cloth covered wire is a resistor wire. I've seen some cars and trucks where one wire is spliced onto another wire for a couple feet, and then spliced to yet another wire, and sometimes there are bad crimp connections, or wire nuts used, and other stuff like that.

Don't connect the tach wire to the distributor at all while trying to figure out why your distributors won't fire. Just connect the power wire. If you have a short in the tach wire or problem with the tach, or if you have a kill switch somewhere in your truck that connects the tach wire to ground, the truck won't start.

If it has a locking clip on the connector, make sure that clip is clipped onto plastic housing of the distributor. Power should come from the 12 gauge pink wire that comes from the ignition switch, or from IGN UNFUSED connector on the fuse panel. If power comes from somewhere else let us know where.

You had the plastic coil cover off for one of your pictures and you mention how you tested for voltage, but I'm not clear on exactly where or how you tested. Inside that cover you have the metal strips that run from the connectors to the coil. Use an alligator clip test wire to connect your volt meter to the metal strip closest to the firewall, and connect your power lead to the underside connector on that same strip. Verify you get voltage with the key on, and during cranking.

The negative lead of the volt meter should be connected to a good ground.

Re: Help with no spark please
 

I thought of this on my way home: I agree with dmj. Trace the wires and check the connections. Somewhere there may be a poor connection or splice. Carries enough current to see 12v on your multimeter or your test light, but not enough current for the distributor to operate.

Re: Help with no spark please
 

Thank you I will do as advised.

I testing for power twice. Once with a test probe and once with my multi meter. Both my probe an meter have the standard needle points end. So I put the Red on the Batt wire and the black on the steel bolt for my master cylinder. With the key on I had the necessary voltage, But when I crank the engine the voltage would drop to 0. With the key on same thing with the test light. It showed power to both the Tach and Batt metal clips.

I also checked the OHMs before the distributor was installed. I test for low and primary resistance. Everything was with in specs from what I had read and researched.

I think that tracing the wires I might find what is going on. I should have done that first. My brain was stuck on mechanical issue because it had been running so good prior to this, it didn't occur to me that it could be wiring.

Thanks for everyone's help on this. As soon as I get her back and running I will post. If I cant find anything with the wires then i'll keep on it. Thanks again.

Re: Help with no spark please
 

Make sure that you intake manifold is grounded to the firewall and the firewall is grounded to the frame and your engine block is grounded to the frame.

Next time you are at the junkyard pick up an HEI module or two and keep it in the glove box for spares. Best if you grab one from a wrecked car, since you know it was functioning when the car crashed :lol:. The old factory OEM HEI modules are way better than any of the aftermarket ones.

Re: Help with no spark please
 

Did your new distributor come with a new coil or did you use your old one? You could have a bad coil, but yes you should trace the 12V wire back and look for any issues. Did you check the underside of your cap to make sure the center pin is still there that touches the rotor. Good luck, keep looking you will find the issue it just takes time.

Re: Help with no spark please
 

I had this problem a few years ago on my Z's LT1. It had shut off a coupe times for no apparent reason but always restarted. Then on a long trip many miles from home it died on the interstate and would not restart. Turned out to be the +12v coil wire has started to die at the connector one strand at a time so it was not capable of supplying enough current.