The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Electrical

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old Yesterday, 01:30 PM   #1
Bunkythe3rd
Registered User
 
Join Date: Jun 2021
Location: Naples Maine
Posts: 4
Truck Won't Run

I am having an issue where I go to turn my truck on and the motor will start when on the starter but when the key returns to the run position I lose spark. The motor then spins down to a stop. I put a timing light on it to verify there was no spark.

One other thing to note is, I was having an issue with the motor stalling out before not starting so I did replace the carburetor during this time to rule out fuel.

Now the stuff I have replace. I have replaced the ingnition switch and the ignition coil. What else should I test or replace?

The fact it is running when on the starter and actually over runs it has me stumped. I have attached photos of the switch and distributor just in case it is something as stupid as a wire is missing.

Thank you to everyone in advance.
Attached Images
  
Bunkythe3rd is offline   Reply With Quote
Old Yesterday, 02:27 PM   #2
dmb
Active Member
 
dmb's Avatar
 
Join Date: Sep 2023
Location: randolph va
Posts: 147
Re: Truck Won't Run

you have the wrong wire hooked to the distributor come off the switchs terminal that that says ign or dist run a new wire as the one on it may be a resister wire
__________________
Old dogs and children and watermelon wine
dmb is offline   Reply With Quote
Old Yesterday, 06:48 PM   #3
Bunkythe3rd
Registered User
 
Join Date: Jun 2021
Location: Naples Maine
Posts: 4
Re: Truck Won't Run

I should also mention i believe this is a later model chevy 350 crate engine. That is the only reason I was thinking it wasn't that the resistor wire was left in but I will have to check because this is how I got it.

What makes you think it is the resistor wire? Is there a marking on it?

Thank you
Bunkythe3rd is offline   Reply With Quote
Old Yesterday, 08:03 PM   #4
dmb
Active Member
 
dmb's Avatar
 
Join Date: Sep 2023
Location: randolph va
Posts: 147
Re: Truck Won't Run

they had a resister wire on the gms up to electronic ign. A yellow wire came off the starter solenoid to the coil to give it 12 volts while cranking and when the switch was turned back to run it would run off the wire from the switch with resistance in it
you did not say what truck you are working on
__________________
Old dogs and children and watermelon wine
dmb is offline   Reply With Quote
Old Yesterday, 08:06 PM   #5
dmb
Active Member
 
dmb's Avatar
 
Join Date: Sep 2023
Location: randolph va
Posts: 147
Re: Truck Won't Run

you have to have 12 vlts at the dist with the switch on, I dont think you have it there. you can check it with a test light
__________________
Old dogs and children and watermelon wine
dmb is offline   Reply With Quote
Old Yesterday, 08:06 PM   #6
RustyPile
Registered User
 
RustyPile's Avatar
 
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,690
Re: Truck Won't Run

A resistor wire has a solid conductor, not strands. Also, the insulation is cloth-like, not vinyl. The wire cannot be soldered, solder will not stick..
RustyPile is offline   Reply With Quote
Old Yesterday, 09:18 PM   #7
Bunkythe3rd
Registered User
 
Join Date: Jun 2021
Location: Naples Maine
Posts: 4
Re: Truck Won't Run

Ok, so if the yellow wire is the 12 volts to the starter, which one is the resistor wire? Is it part of the connector in the back?

Oh also it is a 1969 Chevy C20 by Vin. It has a 67 front end on it.

Last edited by Bunkythe3rd; Yesterday at 09:37 PM.
Bunkythe3rd is offline   Reply With Quote
Old Today, 02:04 AM   #8
RustyPile
Registered User
 
RustyPile's Avatar
 
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,690
Re: Truck Won't Run

I thought I gave a pretty good description of those wires.. OK, I'll try again.. The resistor wire runs from the coil through the harness to the firewall plug. It is readily identifiable as the insulation is cloth like instead of the normal vinyl. Also, it will probably have a faded appearance.. And as you stated, the yellow wire runs from the coil down to the starter.. The 2 wires are joined together at the coil terminal..

Remove both wires, they're not needed, especially the yellow wire as it is "HOT" when the ignition is ON... Separate the firewall connector by removing the bolt in the center. Using needle nose pliers, reach in and grasp the terminal on the edges and squeeze it.. This releases the "catch" and the terminal can be removed. Here is a link to the replacement terminal.. No need to order online, most parts stores have them in stock.

https://www.classicindustries.com/pr...1069ea6c9cfcda

[EDIT] Here is a link to the proper terminal and plug for connecting the new ignition wire to an HEI...

https://www.summitracing.com/parts/s...+5ca6324dae5a6

Last edited by RustyPile; Today at 02:09 AM. Reason: Add information
RustyPile is offline   Reply With Quote
Old Today, 07:01 AM   #9
Bunkythe3rd
Registered User
 
Join Date: Jun 2021
Location: Naples Maine
Posts: 4
Re: Truck Won't Run

You did give a good description. The truck is not where I am currently so I am trying to gather my understanding through the pictures.

Thank you for the help.
Bunkythe3rd is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:19 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com