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Engine Miss

Posted: Sat Feb 08, 2020 12:03 pm
by wayne thompson
My 1925 Fordoor has an engine miss. So far I have installed new carb, installed new buzz coils, installed new timer, checked compression, checked for air leaks at intake, changed spark plugs but still have a miss. Compression is 48-50 psi. Any help would be appreciated.

Re: Engine Miss

Posted: Sat Feb 08, 2020 12:09 pm
by Jim Sims
First find which cylinder is mis firing by shorting out each plug with a screw driver. Then check to see if you have a short in the coil box.

Re: Engine Miss

Posted: Sat Feb 08, 2020 12:15 pm
by Chris Instness
Is it a constant miss or occasional or while accelerating?

Re: Engine Miss

Posted: Sun Feb 09, 2020 4:04 pm
by wayne thompson
Occasional after checking the spark plugs all seem to be firing ok.

Re: Engine Miss

Posted: Sun Feb 09, 2020 5:27 pm
by 70shovelhead
Check for a broken or weak valve spring

Re: Engine Miss

Posted: Mon Feb 10, 2020 5:39 am
by bobt
Check the firing order 1-2-4-3

Re: Engine Miss

Posted: Mon Feb 10, 2020 10:22 am
by Peter, Memphis TN
I vote for a come-and-go short inside the coil box. Or a bad connection inside the coil box.

Re: Engine Miss

Posted: Mon Feb 10, 2020 11:15 am
by Moxie26
You said you installed new buzz coils?.... I would ask you to contact someone who is knowledgeable in your area to calibrate coils not only for electrical values but also the physical positioning of the upper hardware and points..... Sometimes you do get a ignition miss especially noticeable at idle because the points are physically too close together.

Re: Engine Miss

Posted: Mon Feb 10, 2020 11:39 am
by Ron Patterson
Wayne
Have you recently driven the car in the rain or has it somehow gotten wet
Ron Patterson