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 > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 09-02-2012, 12:23 PM   #1
WB72
Before and After
 
WB72's Avatar
 
Join Date: Feb 2000
Location: Leduc, Alberta CANADA
Posts: 632
Electrical problem? Soilid engine start to run bad then not start.

I am a bit baffled.
I have a strong 383 built up and a few weeks ago it started to intermittently run bad, almost like a miss. As i was trying to diagnose the problem, the truck no longer starts. When it was running (badly) I checked the headers with a temp gun and were all similar in temperature, so it wasn't a bad plug.

I have HEI ignition i am thinking it is in good condition, is there someway to check the components?

I have heard it might be my ignition switch, what should I check to verify that?

There is fuel going to the engine, because it doesn't take long to smell the fuel when it is trying to start.

Any help will be very much appreciated.
__________________
Not Grandpa's C-20 anymore...
383 Stroker 425HP, 485Ft/Lbs
Lowered 3.5" Front / 5" Rear
66,000 miles.
Alberta, CANADA
WB72 is offline   Reply With Quote
Old 09-02-2012, 12:55 PM   #2
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,777
Re: Electrical problem? Soilid engine start to run bad then not start.

HEI module!
Common problem.
geezer#99 is offline   Reply With Quote
Old 09-02-2012, 12:57 PM   #3
GASoline71
"I ain't nobody, dork."
 
GASoline71's Avatar
 
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,978
Re: Electrical problem? Soilid engine start to run bad then not start.

In the service manual there are steps to check the module, coil and pick up coil. All you need is a multimeter.

Gary
__________________
'cuz chicks dig scars...

My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread.

The Rebuild of Creeping Death after the wreck

Quote:
Originally Posted by LONGHAIR View Post
I would never rebuild a 305.
Quote:
Originally Posted by prostreetC-10 View Post
I love using vacuum gauges as part of the carb tuning process. I hook the gauge to the inside of my garbage can and leave it there.
Quote:
Originally Posted by Marv D View Post
Remember Murphys 2nd law of mechanical relationships... "OPPOSING COMPONENTS ATTEMPTING TO OCCUPY THE SAME SPACE, AT THE SAME TIME, GENERALLY END UP OCCUPYING ADJOINING SPACE AT THE BOTTOM OF THE OIL PAN"
Quote:
Originally Posted by cableguy0 View Post
Its cheaper to listen to advice given when you ask for help than it is to ignore everyone and wait for carnage.
GASoline71 is offline   Reply With Quote
Old 09-02-2012, 12:59 PM   #4
Xeen
Registered User
 
Xeen's Avatar
 
Join Date: Aug 2012
Location: Topeka Kansas
Posts: 2,655
Re: Electrical problem? Soilid engine start to run bad then not start.


I am sorry to hear you are having engine trouble.
This thread would be better suited over in the "General Truck Forums - Engine and Drivetrain" section of the board because you will get more dedicated help over there.
Good Luck.
__________________
Please call me Brian.
Check out My 1972 SWB Fleetside 5.3L Vortec Restomod Build
Xeen is offline   Reply With Quote
Old 09-06-2012, 12:02 AM   #5
WB72
Before and After
 
WB72's Avatar
 
Join Date: Feb 2000
Location: Leduc, Alberta CANADA
Posts: 632
Re: Electrical problem? Soilid engine start to run bad then not start.

New module, cap, coil, and rotor, still not running. It is running very rough and won't stay running for more than 45seconds. I dont know what to check next...
Posted via Mobile Device
__________________
Not Grandpa's C-20 anymore...
383 Stroker 425HP, 485Ft/Lbs
Lowered 3.5" Front / 5" Rear
66,000 miles.
Alberta, CANADA
WB72 is offline   Reply With Quote
Old 09-06-2012, 07:47 AM   #6
Zeke's Garage
Senior Member
 
Zeke's Garage's Avatar
 
Join Date: Feb 2010
Location: Kennesaw, GA
Posts: 288
Re: Electrical problem? Soilid engine start to run bad then not start.

Have you verified that the power wire feeding your HEI, is good? Did you re-use the old resistor wire that went to the points type coil?

While troubleshooting this issue (And to rule out an issue with the ignition switch), run a single 18 gauge or better wire directly from the battery to the power input of the HEI, just to make sure the issue isn't electrical.

If it still runs poorly or not at all with the direct wire, you might want to pull the HEI and check that the shaft and gear are in good shape.

While the engine is running, does it backfire or pop through the carb?

Have you checked the initial timing of the engine again? Maybe something went wonkey with the timing chain?

Depending on who put them together, new engines can develop all kinds of crazy issues.


Good luck


Shawn
Zeke's Garage is offline   Reply With Quote
Old 09-06-2012, 08:33 AM   #7
CC69Rat
Senior Member

 
CC69Rat's Avatar
 
Join Date: Jan 2011
Location: Chattanooga TN
Posts: 6,224
Re: Electrical problem? Soilid engine start to run bad then not start.

I'm thinking the resistor wire too. you may not be getting a full 12v to the HEI. ^^ In agreement with Zeke.
__________________
Chad

1967 C10 SWB - Project Savannah - 6.0/4L80 *Currently underway*
1968 C10 SWB - TOTY 2018, 50th Anniversary Tribute Project * Sold * Pride and Joy
1986 Silverado Short Fleet - Scarlet *Sold*
1985 Silverado Short Fleet *Sold*
2022 Jeep Gladiator Mojave
2001 Jeep Cherokee XJ 4x4 - Lifted, Built
1992 Jeep Cherokee XJ 4x4 - Lifted
2013 Honda Accord EX-L v6 Coupe 6spd (wife's ride)
CC69Rat is offline   Reply With Quote
Old 09-06-2012, 09:22 AM   #8
low&slow
Account Suspended
 
Join Date: Jan 2009
Location: Kuna, Idaho
Posts: 1,046
Re: Electrical problem? Soilid engine start to run bad then not start.

I had the same problem with my truck. Couldn't figure it out if my life depended on it. Just an idea, but you could just put a push button start in like I did lol. Other than that as for not running very long, You probably have a slight short somewhere lol.

Sorry not very much help
low&slow 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 04:07 AM.


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