Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / engine backfire

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: engine backfire -- page: 1 2     ken ct. 03-10-2013 @ 6:28 PM reply profile send p.m. Senior Posts: 1513 Joined: Jan 2010 It only takes 1 back fire through the carb to blow out PV. Check it for sure. Youve had many according to your statements. ken cy. Stroker 03-05-2013 @ 1:18 PM reply profile send p.m. Senior Posts: 1460 Joined: Oct 2009 MG: Only if it is due to a lean mixture. MG 03-05-2013 @ 9:50 AM reply profile send p.m. Senior Posts: 1262 Joined: Nov 2009 Stroker, Will pulling the choke out cure the backfire through the carb? Stroker 03-04-2013 @ 5:33 PM reply profile send p.m. Senior Posts: 1460 Joined: Oct 2009 Well, the term "physics" scares most of us without a doctor's degree in math, but basically, a lean fuel mixture will burn faster than a stoichometric (read as: "just right") mixture. A very lean fuel mixture can start burning before the intake valve closes, which results in flames from the cylinder going backward into the intake manifold with a resulting minor explosion, which results in a "backfire" through the carb. That's why we always ask if it is backfiring through the intake, or the exhaust. 39topless 03-04-2013 @ 12:09 PM reply profile send p.m. Member Posts: 77 Joined: Feb 2013 Great help, I am going to rebuild the carb and hope that will do it. I don't quite understand the physics behind the backfire but if rebuilding the carb solves the problem, that's all I need to know. Thanks to you all for the excellent advice. This forum is great, Phil 37RAGTOPMAN 02-28-2013 @ 3:52 PM reply profile send p.m. Senior Posts: 1969 Joined: Oct 2009 39topless I had the same problem with a MODEL A, the plugs were dirty,it was poping though the carb, This was in a rebuilt engine,I think breaking it in, caused to it to soot up,maybe to much slow speeds.? and I disected the carb,points timing,etc, there is not alot to look for in a simple system like a MODEL A I found solution in a old time repair manual, make sure you have the correct plugs [heat range] in for your type of driving, I can tell you I had a problem with original CHAMPIONS, in my 37 ,they were very old,and one or 2 were burnt away,from many years of use, I tried a set of NGK, Let me tell you that my 37 runs very well with them it it, I was Amazed how much more power it has, and seems like it gets better MPG, My 3 cents 37RAGTOPMAN supereal 02-27-2013 @ 6:51 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 A sticking valve wouldn't affect all five cylinders. Sooty plugs usually indicate an over rich fuel mixture. In the carb, the only part that would affect more than four cylinders is the power valve because each side of the carb feeds four cylinders only. It is probable that either the power valve is leaking, or its gasket is the source of excess fuel, and also causing the backfire. It can also be due to carb flooding caused by overfilling. In that case, suspect the float.or the float is hanging up. I'll bet your problem will return. It only takes one backfire thru the carb to blow out the diaphragm in the power valve. This message was edited by supereal on 3-1-13 @ 8:38 AM 39topless 02-27-2013 @ 5:47 PM reply profile send p.m. Member Posts: 77 Joined: Feb 2013 Ok, figure this one out. I checked for vacuum leaks,none. I pulled all the plugs, 5 were very black, cleaned and replaced and did a compression check. All between 55-75. Started up the engine, NO backfire. I am guessing maybe a hanging valve decided to be good.??? Thanks for all your help. Phil oldford2 02-22-2013 @ 5:18 PM reply profile send p.m. Member Posts: 275 Joined: Oct 2009 If you have been getting backfires thru your carb your power valve may be blown too and leaking gas down the throat. Check it also. John 39topless 02-22-2013 @ 8:50 AM reply profile send p.m. Member Posts: 77 Joined: Feb 2013 Great suggestions. I will get on this this weekend and post my results. Thanks so very much.

<< previous || next >>

PAGE: 1 2

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1