Need your ideas please on this problem - Pontiac GTO Forum
User Tag List

 1Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 07-21-2019, 09:47 PM Thread Starter
 
Join Date: Mar 2017
Posts: 63
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Need your ideas please on this problem

1969 Pontiac Tempest I bought about 4 years ago with a 400 (non original) engine. Car has been running flawlessly since I have owned it, but tonight, the wife and I went out in it, and as I was accelerating, it bucked and felt like someone turned the switch off, but immediately caught and continued to run. It did this several more times in the next two to three miles of driving, then when I was coasting down a hill, it stalled. Pulled over, and it would crank but not start. waited a minute or two and it started up and ran find for another few minutes then stalled again.

Got it home and it was idling in my driveway while I was looking around the engine compartment. While I was doing this it just died, like somebody shut they key off. I pulled the coil wire and it had spark when I cranked it, put the coil wire back into the cap and it started up again. I did a pertronix conversion two years ago, but I heard that when they go bad, the car will not start at all. I checked all the grounds and the battery cables and they are all clean and tight. Any ideas of where to go from here? I'm now reluctant to take the care our for fear of getting stuck.

Any help is appreciated
ajluzi1957 is online now  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 07-22-2019, 10:13 AM
 
Join Date: Jul 2016
Location: North Louisiana
Posts: 633
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 73 Post(s)
I have heard of problems with the pertronix conversions.

If mine, I think I'd either switch back to points, or switch to an HEI. Obviously, the factory points dist will LOOK more original. Points are also MUCH less likely to leave you stranded. They usually give some warning, rather than just killing the engine. Back before the HEI came along, we ran points in everything, for street & race. MANY millions of vehicles used points, including all the '60's & early '70's Musclecars. It is a very reliable system, IMO.

Another plus for using points is that you can keep the plugs wires you have now.

But, if you wanna try an HEI, & can't come up with a good used one, you might wanna try one of the cheap Chinese models. They sell on Ebay for around $50 & less. SOME guys have reported having good luck with 'em. Some say it's best to swap in a good aftermarket module. Some say they're total junk.

https://www.ebay.com/itm/Pontiac-301...UAAOSwUMVaIY~u

But, if you wanna go with a better quality HEI, the DUI brand is considered, by many, the best. They're just over $300, from Summit. Summit sells several brands.

https://www.summitracing.com/parts/d...w/make/pontiac

https://www.summitracing.com/search/...20distributors

Last edited by bigD; 07-22-2019 at 10:56 AM.
bigD is online now  
post #3 of 16 (permalink) Old 07-22-2019, 03:59 PM
 
joelau27's Avatar
 
Join Date: Sep 2018
Location: Massachusetts
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
How fresh is the gas, maybe fill the tank from a different station.
joelau27 is online now  
 
post #4 of 16 (permalink) Old 07-22-2019, 07:16 PM
 
RMTZ67's Avatar
 
Join Date: Mar 2011
Location: Albuquerque N.M
Posts: 293
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 83 Post(s)
Garage
If you got spark, then check your fuel filter. Take your fuel line at the fuel pump, take your gas cap off and blow through with a compressor. I had a similar issue once seemed like vapor lock and out of the blue I decided to do that and I heard something forced through. I cleaned and rinsed my tank years before so I don't know what it was. Never done it again tho.
RMTZ67 is online now  
post #5 of 16 (permalink) Old 07-22-2019, 07:20 PM
 
Lemans guy's Avatar
 
Join Date: Oct 2014
Location: Nashville, Tennessee
Posts: 765
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 79 Post(s)
Pop off that distributor cap and look real good with a flashlight all around the ignition module. Look for oil......if you see oil crankcase pressure is pushing oil up into the distributor. What that then does is covers the thin cellophane cover over the magnets on the magnet ring and on top of the module.

It will cause just those symptoms intermittent stall, as the oil film interferes with the Hall effect magnet trigger. If it is oil you can plug 4 of the five bottom holes in the dist shaft with RTV or drill some holes to relieve that problem. Then you can correct your PCV Breather system as a bad one causes this pressure.

If not oil check the grounds on the module for loose screws to the dist body, they are very sensitive to grounds. Tighten up and clean up all grounds, even battery to engine and engine to frame. You can test the ground on the module with a direct test wire to negative battery terminal, should have very low resistance.

Use an ohm meter on 200 scale, pos of meter to module plate, negotiations meter to neg battery terminal POST, not clamp. Should be less than .2 ohms, if more find the bad or weak ground.

If that is OK recheck gap on module to magnetic ring or lobes depending which model you have. The modules are very sensitive to that gap should be 10 thousands to 60 thousands....usually 20 to 30 is normal. If it gets loose or out of wahack will only Fire sometimes, giving an intermittent problem.

If that is ok verify your ignition wire provides a full 12 volts to the coil and make sure it is not coming thru a ballast wire that drops the module down to 9 volts which is what points need so they donít burn up. These modules can work on reduced voltage but perform best at full 12 volts.

It is an easy fix with a relay and very reliable if you have reduced voltage from a ballast wire. There are a few ways to fix it

Those are 4 things I would check, if those are all ok could be a weak coil, check with ohmeter and could be fuel pressure as well....

You just have to do some tests
Lemans guy is offline  
post #6 of 16 (permalink) Old 07-22-2019, 08:30 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,739
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 404 Post(s)
Garage
Quote:
Originally Posted by joelau27 View Post
How fresh is the gas, maybe fill the tank from a different station.

X2 on the bad gas. Take a slug of water and it'll do as you say. Pertronix is a good set-up. The earlier units got a bad rap, mostly because if you left the key/power on and the engine was not running, it would burn them out. The fact that it was bucking would have me looking elsewhere. With electronic ignitions, to include HEI, my experience is they either work or don't.

If you have spark, then it is not ignition. Replace the fuel filter just to be sure that is not your issue. Pour a cap full of gas down the carb or give it a shot of ether and see if it catches. If it does, my money is on bad gas. If the car sits for a while, the ethanol in the gas can absorb water over time. If you filled up and the place you went was perhaps low on gas in the in-ground tank or they just got serviced from a tanker, you may have sucked up a dose of water.

If that checks out OK, then I would begin the hunt for an electrical issue.
PontiacJim is offline  
post #7 of 16 (permalink) Old 07-23-2019, 08:27 AM Thread Starter
 
Join Date: Mar 2017
Posts: 63
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Thanks all for the help. I know it's not the fuel as the car does not sputter or fade out, it just shuts off, plus the fuel is fresh.

I think Lemans guy has the answer, but I haven't done those tests yet. I swapped back my old points distributor and car is running fine in the garage. Couldn't take it out last night because of the torrential rain around here, but hope to this evening. Will let you know what finally happens.
ajluzi1957 is online now  
post #8 of 16 (permalink) Old 07-23-2019, 10:03 AM
 
Join Date: Jul 2016
Location: North Louisiana
Posts: 633
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 73 Post(s)
Quote:
Originally Posted by ajluzi1957 View Post
...I swapped back my old points distributor and car is running fine in the garage...
"...verify your ignition wire provides a full 12 volts to the coil and make sure it is not coming thru a ballast wire that drops the module down to 9 volts which is what points need so they don’t burn up. These modules can work on reduced voltage but perform best at full 12 volts..."


If you had switched to a full 12 volts, make sure you switch back, while you are using the points. If you don't have the original resister wire, you can buy a cheap inline resister. That's how I ran most of my bracket engines. Had an on/off toggle switch & a direct 12 volt wire, to which I installed an aftermarket resister. I mounted the resister on the firewall, close to the coil.

https://www.google.com/search?rlz=1C...TcLAmgQ4dUDCAo

https://www.hotrod.com/articles/choo...ignition-coil/

http://www.pertronix.com.au/troubleshooting.html

Last edited by bigD; 07-23-2019 at 10:30 AM.
bigD is online now  
post #9 of 16 (permalink) Old 07-23-2019, 11:02 AM Thread Starter
 
Join Date: Mar 2017
Posts: 63
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Thanks Big D.

When I installed the pertronix, I kept the original resistor wire taped up and out of the way and ran a switched 12v source to the pertronics, so when I swapped back last night, I just hooked up the old resistor wire and all is good
ajluzi1957 is online now  
post #10 of 16 (permalink) Old 07-24-2019, 08:44 AM Thread Starter
 
Join Date: Mar 2017
Posts: 63
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Just an update. Was able to get the car out last night for an extended ride with the points distributor. All is well, so I will leave the points in there and decide down the line if I want to troubleshoot and reinstall the pertronix at some point. thank you all for the help
ajluzi1957 is online now  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO General Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome