The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   The 1967 - 1972 Chevrolet & GMC Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=3)
-   -   Ignition question (https://67-72chevytrucks.com/vboard/showthread.php?t=595010)

71 super 08-31-2013 11:18 PM

Ignition question
 
Help i am having ignition troubles that just showed up. truck runs ok for a of time- three miles or so sputters and then dies. will spin over a couple of times with no fire and then acts as if there is no power. I replaced coil on hunch and changed fuel filter, cranked and ran ok. Couple of miles later I am back to where I started earlier. Have I fried the pertronix module or is it a resistance issue? Mind you I have drive truck quite a bit as it was set up and now this problem raises its head.. .. I have a pertronix replacement pick- up and now their 1.5 ohm coil(original delco tested at 3 ohms). The resister yellow wire shows 11.56 volts with switch on, with positive meter line at coil and jumper to ground still shows less than 12 volts. The battery shows 12.5 volts across terminals. According to pertronix , the unit must have 1.5 coil no resistance wire and 12 volts minimum to positive side of coil. What is the best method to get the 12 volts there? I felt like I could go from unfused terminal at fuse block to get the 12 volts I need( done this before to hei types). Any suggestions are appreciated.
Posted via Mobile Device

luvbowties 09-01-2013 02:58 AM

Re: Ignition question
 
Just for experimenting, use that terminal from fuse box to operate a relay; run a fused wire directly from +BATT to relay--and then, when actuated by fuse-box terminal--from other output terminal to coil. Will give full batt voltage to coil, definitely above 12 volts(13.5-range) IF your BATT is good.
Sam

So.Cal.Super 09-01-2013 03:24 AM

Re: Ignition question
 
since you mentioned fuel filter. where is it located in line, before or after the pump?

cdowns 09-01-2013 06:16 AM

Re: Ignition question
 
i have always just removed the resistaance wire from the harness and installed a new wire to the bulkhead connection then rewraped the harness and got a nice factory lookin harness with the updated wiring

jcd9730 09-01-2013 06:48 AM

Re: Ignition question
 
Sounds like resistance issue. Resistance=heat and low voltage. Bad/old connections or splices somewhere lowering voltage as it heats up probably.

Check out madelectric. I put his 'New System' in, and it came with a lot of good info and turned out to be a really good upgrade for the money. Ran better and stronger afterwards too.

71 super 09-01-2013 09:50 AM

Re: Ignition question
 
The fuel filter was at carb, and it was offering resistance. The harness is a new harness from m&h, truck was restored 13 years ago but had sat a lot. The pertronix has been in place for at the entire time, however,this issue just showed up. Have had intermittent fuel issues but beginning to think that it has been an ignition problem due to resistance. I am going to make up a jumper and try that to see how it goes.
Posted via Mobile Device

chipflyer 09-01-2013 10:01 AM

Re: Ignition question
 
Don't overlook the fuel pickup tube in the tank Harold. I had a 70 Gmc about ten years ago that started acting like that and it ended up being an almost completely plugged up pickup tube, I'm sure that truck was not the only one that had that going on but you rarely see anyone else find the same thing. I also have done and recommend what cdowns did for a power source, replace the resistor wire at the bulkhead. It's the wire that drops the voltage, it's 12volts at the terminal.
Good luck

Jeff
Posted via Mobile Device
Posted via Mobile Device

msgdsrf 09-01-2013 10:25 AM

Re: Ignition question
 
Sounds more like a fuel issue and also consider looking for a stuck needle. Sounds to me like a flooding issue. Next time take a look at float bowl levels when it dies on you. Lower than at rest then maybe filter, etc.. Higher, needle/seat.


All times are GMT -4. The time now is 08:27 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com