Help with no spark please
 

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

Re: Help with no spark please
 

What distributor is it?

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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?

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

:lol: 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.

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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??

Re: Help with no spark please
 

[QUOTE=RustyPile;8931879]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" I upgraded


I upgraded the alternator to a 12si 100amp about 6 months ago before I pulled it into my garage for the winter. I got the distributor off Amazon and I can return it, I just can't imagine it's faulty, its brand new. I took the cap off and turned the engine over and the distributor turned which tells me it's not mechanical. I just dont get why I can't get spark.
Test lights show power when the key is in the on position to both sides of the distributor. I checked the ohms and everything is where it should be. The fuses are good. The wires look good. The distributor I took out had the same issue,just couldn't get spark all the sudden.

Re: Help with no spark please
 

Bad ignition module in the distributor..... was the distributor you took out also HEI? If so what is the reason you swapped it? If it was, and it worked, try pulling the module from the old distributor and putting it in this one. Many parts stores can test the ignition module. I carry a spare in the glove box. I went through a very frustrating period when the engine would just stop running like turning off the key. Finally tracked it to faulty ignition module. Seems like quality control on them has gone down hill. There are many threads on the subject. I’m sure others can chime in on which seem most reliable.
If you do swap the module be sure to put real heat sink paste under it, not dielectric grease.

Re: Help with no spark please
 

Hey cruiser it's frustrating as he'll. The very first thing I did was replace the module. I bought the last ACCEL from napa here and put it on the old distro I had hoping I would now have spark. After that didn't work I said screw it and just bought a complete new distributor which comes with the control module and everything else, I also bought to plug wires and installed the new distro and wires at the same time. Hoping that would fix it but after doing that today I still have no spark. I am going to check the ground wire from the distro to the engine, I highly doubt it will work. I pick up the ignition cylinder tomorrow and will change that out. I don't know what else I can do after that. I'm completely dumbified

Re: Help with no spark please
 

Hay Conoco, I tell this to people all of the time. New doesn't mean it's any good.

Re: Help with no spark please
 

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.

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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

Re: Help with no spark please
 

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.

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.