1978 random misfiring
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Joined: Jun 2015
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1978 random misfiring
Hey guys, thanks in advance as always for any advice.
Last week I noticed some kind of random in-and-out misfiring. Whenever the car reaches operating temperature, it feels like a cylinder drops out and then comes back in. Never when the car is cold, will be driving along and suddenly it's running rough, then kicks back in fine.
Distributor cap was replaced by mechanic maybe 6 mos ago. Any idea what could cause this? Video attached showing it kick out at the end. It also sounds like some kind of spark knock maybe? Thanks
http://vid3.photobucket.com/albums/y69/bjammerz/Mobile%20Uploads/trim.7A26F30B-DD8E-478D-83BB-28D01033DA88_zpshx13ips5.mp4
Last week I noticed some kind of random in-and-out misfiring. Whenever the car reaches operating temperature, it feels like a cylinder drops out and then comes back in. Never when the car is cold, will be driving along and suddenly it's running rough, then kicks back in fine.
Distributor cap was replaced by mechanic maybe 6 mos ago. Any idea what could cause this? Video attached showing it kick out at the end. It also sounds like some kind of spark knock maybe? Thanks
http://vid3.photobucket.com/albums/y69/bjammerz/Mobile%20Uploads/trim.7A26F30B-DD8E-478D-83BB-28D01033DA88_zpshx13ips5.mp4
Last edited by 1978BackToLife; May 7, 2016 at 12:56 PM.
Safety Car
Joined: Apr 2006
Posts: 4,057
Likes: 421
From: BC
Hey guys, thanks in advance as always for any advice.
Last week I noticed some kind of random in-and-out misfiring. Whenever the car reaches operating temperature, it feels like a cylinder drops out and then comes back in. Never when the car is cold, will be driving along and suddenly it's running rough, then kicks back in fine.
Distributor cap was replaced by mechanic maybe 6 mos ago. Any idea what could cause this? Video attached showing it kick out at the end. It also sounds like some kind of spark knock maybe? Thanks
http://vid3.photobucket.com/albums/y...pshx13ips5.mp4
Last week I noticed some kind of random in-and-out misfiring. Whenever the car reaches operating temperature, it feels like a cylinder drops out and then comes back in. Never when the car is cold, will be driving along and suddenly it's running rough, then kicks back in fine.
Distributor cap was replaced by mechanic maybe 6 mos ago. Any idea what could cause this? Video attached showing it kick out at the end. It also sounds like some kind of spark knock maybe? Thanks
http://vid3.photobucket.com/albums/y...pshx13ips5.mp4
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Distributor cap quality could be an issue; but problem is more likely related to ignition system. If you have an electronic ignition system, heat is the enemy of that type system. Module is usually the 'problem'.
If you still have points, the condensor is usually first to go and it starts with erratic miss condition. "Dirty" points can be the issue also; remove and file/sand clean and smooth...retry. (Or replace)
With either type of system, the coil can eventually start to break down and cause miss condition.
If you have some "substitutes" for any of these items, you can "swap and test".
If you still have points, the condensor is usually first to go and it starts with erratic miss condition. "Dirty" points can be the issue also; remove and file/sand clean and smooth...retry. (Or replace)
With either type of system, the coil can eventually start to break down and cause miss condition.
If you have some "substitutes" for any of these items, you can "swap and test".
