Sign up to remove ads. We'd love to have you amongst our ranks! Just Click here!


pontiac forums   pontiac forums

Go Back   Pontiac Forums > Pontiac Car Forums > Pontiac LeMans Forum

Advertisements
cars connected social network






Notices

Pontiac LeMans Forum Discuss topics regarding the Pontiac LeMans.

Pontiac Forum: 67 Lemans 326 Intermittently Missing
Reply
 
Thread Tools
  #1  
Old August 31st, 2018, 05:17 PM
LeMans326's Avatar
LeMans326 LeMans326 is offline
Junior Member
 
Join Date: Dec 2017
Location: Flint, MI
Posts: 11
LeMans326 is on a distinguished road
67 Lemans 326 Intermittently Missing

I purchased this car about a year ago. When I bought it it had been running rich, and the exhaust was sooty (would leave black marks on the ground when first starting it), and I've been trying to get everything back into good shape. Earlier this year the car started randomly missing after getting warmed up. I assumed the plugs were probably in bad shape so I pulled them and replaced them with new Delcos. The miss went away and the car drove great, however during a rolling cruise a few weeks ago it started missing again. Car was not overheating or anything, and it didnt get any better once I headed home. By the time I pulled in the driveway it was missing so badly that it would stall at idle. Over the past couple weeks, I have checked the following:

Replaced Coil
Replaced Voltage Regulator
Checked and regaped Points
Visual inspection on ground straps/wiring
Visually inspected plug wires
Visually inspected cap/rotor
Checked fuses.

The car cranks strong, and occasionally when it's cold it will run pretty good, but it always misses again once it warms up.

I have a dwell meter/DC volts meter I had hooked up. And I switched it over to Volts while it was hooked to the coil

It read 6 volts at key on/engine off
And would jump to around 12 volts when cranking, and then fall immediately to 3 or 4 volts and stay there when the engine was running.

This car has been a "learn as I go" type of project, and I appreciate in advance any tips or insight!
Reply With Quote

  #2  
Old September 1st, 2018, 11:20 AM
melsg5's Avatar
melsg5 melsg5 is offline
Senior Member
ADMINISTRATOR
 
Join Date: Dec 2008
Posts: 18,344
melsg5 is on a distinguished road
You state you have a dwell meter, did you set the dwell to 30 degress and then set the timing with vacuum advance disconnected?
when you reconnect the vacuum advance to a vacuum souce does the timing advance?
Assuming the points look good, not burnt, did you try replacing the points condenser?
Did you use your meter set it for ohms and measure the resistance on each wire, no more than 1k per foot of wire.
What number plug did you install and did you gap them to .035?
Hve you checked the voltage readings you get on another car to make sure the meter is reading correctly. You should not be seeing 3 or 4 volts at any time ?
with the engine running is the alternator putting out 13.5 to 14.5 volts?
which carburetor is on the car, 2bbl or 4bbl rochester?
__________________
1971 GTO 455 HO Ram Air
Reply With Quote
  #3  
Old September 1st, 2018, 07:07 PM
Kraig1957's Avatar
Kraig1957 Kraig1957 is offline
Member
 
Join Date: Oct 2017
Location: Central California
Posts: 34
Kraig1957 is on a distinguished road
I think 1967 was the last year they used the Carter AFB for the 4BBL carb. It wasn't until 1968 when they started using the Rochester for the 4BBL carb.
__________________
1964 Pontiac Catalina 389V8+.060, Rotohydromatic 375
1972 Pontiac Lemans 400V8+.020, Turbohydromatic 400
1967 Ford F-100, 352V8, C6 automatic transmission
2003 Ford Crown Victoria, 4.6LV8, automatic transmission
2016 Ford F-350 Dually, 6.7L Turbo Diesel, Automatic transmission
2016 Ford Mustang, 5.0LV8, Automatic transmission
Reply With Quote
  #4  
Old September 2nd, 2018, 10:00 AM
LeMans326's Avatar
LeMans326 LeMans326 is offline
Junior Member
 
Join Date: Dec 2017
Location: Flint, MI
Posts: 11
LeMans326 is on a distinguished road
The car has a 2bbl carb.

I did verify the dwell meter/volt meter are both accurate.

Dwell is at 30°

Timing is set correctly, and vaccuum advance is working

Plugs are gapped correctly

I have not replaced the condenser yet, though I did replace the points just to be sure and there was no difference.

I am still reading 3 volts on the coil when engine is running. I'm starting to wonder if the ignition switch may be bad. I'm going to run a bypass wire from the battery to the coil and see if everything smooths out.
Reply With Quote
  #5  
Old September 2nd, 2018, 11:08 AM
melsg5's Avatar
melsg5 melsg5 is offline
Senior Member
ADMINISTRATOR
 
Join Date: Dec 2008
Posts: 18,344
melsg5 is on a distinguished road
with the engine running and the voltmeter attached to the battery do you get 13.5 to 14.5 volts?
The coil positive terminal has a dual wire, one comes from the starter and supplies full battery voltage when cranking. The other is a resistance wire coming from the switch and lowers the voltage to about 9 volts. Does anything look suspicious about that dual wire where it connects to the positive terminal of the coil?
__________________
1971 GTO 455 HO Ram Air
Reply With Quote
  #6  
Old September 2nd, 2018, 11:16 AM
melsg5's Avatar
melsg5 melsg5 is offline
Senior Member
ADMINISTRATOR
 
Join Date: Dec 2008
Posts: 18,344
melsg5 is on a distinguished road
First year for Pontiac usage of Quad

Quote:
Originally Posted by Kraig1957 View Post
I think 1967 was the last year they used the Carter AFB for the 4BBL carb. It wasn't until 1968 when they started using the Rochester for the 4BBL carb.
Read this link
http://www.mre-books.com/quadrajet/index.html
__________________
1971 GTO 455 HO Ram Air
Reply With Quote
  #7  
Old September 4th, 2018, 10:05 AM
cammerjeff's Avatar
cammerjeff cammerjeff is offline
Senior Member
 
Join Date: Nov 2013
Location: Belleville MI
Posts: 396
cammerjeff is on a distinguished road
As said I would check for the 8 to 9 volts to the coil with the engine running, also if you have not replaced the plug wires I would, in my experience they can only be counted on to perform well for about 5-7 years. They may look fine but can break down internally.
__________________
2009 G8 GT
2006 Mallet LS2 Solstice
1978 Catalina Safari Buick 350 TH350
1978 Sunbird Safari Buick 3.8 2004R
1977 Astre Formula 215 Buick V8 T-5
1973 Lemans Safari 400 4-speed (factory)
1971 Catalina Freeway Enforcer 455 TH400
1969 Firebird Sprint 301 OHC-6 T-5
Reply With Quote
  #8  
Old September 5th, 2018, 12:32 PM
LeMans326's Avatar
LeMans326 LeMans326 is offline
Junior Member
 
Join Date: Dec 2017
Location: Flint, MI
Posts: 11
LeMans326 is on a distinguished road
I appreciate everyone's help!

It's fixed! Turns out it was the condenser for the points that was bad. Replaced it and it's never run better!
Reply With Quote
  #9  
Old September 5th, 2018, 01:29 PM
melsg5's Avatar
melsg5 melsg5 is offline
Senior Member
ADMINISTRATOR
 
Join Date: Dec 2008
Posts: 18,344
melsg5 is on a distinguished road
excellent news
__________________
1971 GTO 455 HO Ram Air
Reply With Quote
  #10  
Old September 6th, 2018, 08:20 AM
cammerjeff's Avatar
cammerjeff cammerjeff is offline
Senior Member
 
Join Date: Nov 2013
Location: Belleville MI
Posts: 396
cammerjeff is on a distinguished road
That's Interesting, I always replaced the Condenser when changing the points as it usually came with the Kit, but I actually never had one go bad. Thanks for the update.
__________________
2009 G8 GT
2006 Mallet LS2 Solstice
1978 Catalina Safari Buick 350 TH350
1978 Sunbird Safari Buick 3.8 2004R
1977 Astre Formula 215 Buick V8 T-5
1973 Lemans Safari 400 4-speed (factory)
1971 Catalina Freeway Enforcer 455 TH400
1969 Firebird Sprint 301 OHC-6 T-5
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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 02:14 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
pontiacforum.com recognizes that "Pontiac", it's logos and various model names and numbers are registered trademarks of the General Motors Corporation. These terms are used for identification purposes only. pontiacforum.com is not affiliated in any way with the General Motors Corporation, Pontiac or any other company listed herein. All information on this site is the opinion of its members and not the opinion of the site itself. ©2017 pontiacforum.com. All rights reserved.


MADISON ROSS MEDIA GROUP MARKETPLACE
Need products for your Pontiac? Check out your options at the links below:

Miss the Pontiac G8 GT? Believe it or not, Kia may have something for you. The Kia Stinger is a large sport-oriented hatchback sedan in the mold of the Audi A7.