The Ford Barn

cottonginner · 05-14-2013, 08:54 PM

What is first thing to look for if my A misses at higher rpm?It idles fine.

BRENT in 10-uh-C · 05-14-2013, 09:39 PM

Generally speaking it will be spark related but it could be one of several things. The first thing I would check would be points gap and make sure they are dressed properly. Coil polarity that is reversed will cause hi-speed issues too. If it is fuel related, maybe the GAV is too lean? Amazing what hearing does for diagnosis!!

HoarseWhisperer · 05-15-2013, 10:58 AM

I'll go along with Brent's suggestion on the first and easiest thing.

Changing plugs won't solve incorrect gap or pitted points.

ford3 · 05-15-2013, 01:00 PM

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how many of you remember the old spark plug testing machines? the one where you put the plug in the machine, applied spark and watched the plug fire, if it couldnt spark at 125# psi you replaced the plug, basically the same thing happens in an engine at higher rpms, the pressure builds up to a point where the spark cant jump the plug gap, thus a high rpm miss, but any thing in the electrical system may cause that, coil, condensor, points, rotor,cap, spark plugs and coil wires, to make sure you have the best chance of stopping that, but american parts, if offered chinesse parts tell the parts guy to flush then down the toliet, because they are sh**, pay more and get a lot more confedence in your engine, start with the plugs as was suggested in more than one reply

05-14-2013, 08:54 PM	#1
cottonginner Junior Member Join Date: Mar 2013 Posts: 3	Engines misses at higher rpm What is first thing to look for if my A misses at higher rpm?It idles fine.

05-14-2013, 09:39 PM	#2
BRENT in 10-uh-C Senior Member Join Date: May 2010 Location: Eastern Tennessee Posts: 11,508	Re: Engines misses at higher rpm Generally speaking it will be spark related but it could be one of several things. The first thing I would check would be points gap and make sure they are dressed properly. Coil polarity that is reversed will cause hi-speed issues too. If it is fuel related, maybe the GAV is too lean? Amazing what hearing does for diagnosis!! __________________ . BRENT in 10-uh-C . www.model-a-ford.com ...(...Finally Updated!! ) .

05-15-2013, 10:58 AM	#3
HoarseWhisperer Senior Member Join Date: May 2010 Location: Ontario, Canada Posts: 1,470	Re: Engines misses at higher rpm I'll go along with Brent's suggestion on the first and easiest thing. Changing plugs won't solve incorrect gap or pitted points. __________________ I know a lot of things; I just can't remember them all. 1928 CCPU 82-A 1931 Roadster 40-B Dlx (Canadian)

05-15-2013, 01:00 PM	#4
ford3 Senior Member Join Date: Oct 2012 Location: oroville calif. Posts: 1,453	Re: Engines misses at higher rpm Sponsored Links (Register now to hide all advertisements) how many of you remember the old spark plug testing machines? the one where you put the plug in the machine, applied spark and watched the plug fire, if it couldnt spark at 125# psi you replaced the plug, basically the same thing happens in an engine at higher rpms, the pressure builds up to a point where the spark cant jump the plug gap, thus a high rpm miss, but any thing in the electrical system may cause that, coil, condensor, points, rotor,cap, spark plugs and coil wires, to make sure you have the best chance of stopping that, but american parts, if offered chinesse parts tell the parts guy to flush then down the toliet, because they are sh**, pay more and get a lot more confedence in your engine, start with the plugs as was suggested in more than one reply