Ignition issue.
Jul 14, 2015 | 12:58 PM
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Ignition issue.
72, 454 HEI and MSD box.
Car was unstable at idle but ran fine otherwise.
Red that pluggap should be 0,045 with HEI, had 0,035 previously.
Adjusted to 0,045 and the car ran like crap when it got hot, stumbles and misfires.
Went back to 0,035 and it still runs like crap...
Could it be that plugs or coil has been damaged.
Strange thing is, when it is Cold it runs perfect.
Please someone, give me a solution!
Jul 14, 2015 | 03:07 PM
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
You have a vacuum leak. When it's cold the choke is closed and masking the problem.
Jul 14, 2015 | 03:11 PM
Drifting
Joined: Sep 2010
Posts: 1,412
Likes: 50
From: Laguna Niguel California
What is the quality of your spark plug wires? Big blocks have always been sensitive to spark plug wire quality.
Jul 14, 2015 | 04:10 PM
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Quote:
Originally Posted by
dochorsepower
What is the quality of your spark plug wires? Big blocks have always been sensitive to spark plug wire quality.
It ran just fine Before i started to fiddle with sparkplug gap...
Jul 14, 2015 | 04:13 PM
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Quote:
Originally Posted by
dochorsepower
What is the quality of your spark plug wires? Big blocks have always been sensitive to spark plug wire quality.
MSD street fire wire, ran god Before plug adjustment.
But i have been thinking of that and the coil.
Jul 14, 2015 | 04:40 PM
Race Director
Joined: May 2006
Posts: 18,668
Likes: 2,564
could you have broken the connection in the spark plug boot by pulling on them when changing the plugs? Do you have an ohm meter to test them?
Jul 14, 2015 | 04:48 PM
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Quote:
Originally Posted by
MelWff
could you have broken the connection in the spark plug boot by pulling on them when changing the plugs? Do you have an ohm meter to test them?
Checked all plugs before reinstalled them, did not ohm them.
Did ohm all Cables, could not detect any issus.
Thing is, why does it run god when cold??
Jul 15, 2015 | 05:46 PM
Race Director
Joined: Sep 2005
Posts: 18,640
Likes: 121
From: Farragut,TN
leaning out after choke is off. probably a vacuum leak.
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Jul 16, 2015 | 12:17 PM
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Pulled all plugs again and found one that had a small almost not visible crack.
I am so relieved!