The Ford Barn

adileo · 07-08-2019, 06:01 PM

My 39 coupe - EAB engine - all listed below 2- closer to 3 years old
dual Edlebrock 94s built by Charlie
Disto built to 11A by Bubba
Coil built by Skip
Radiator pulled this winter and had it cleaned. Car @ 95F runs no higher than 190 which to me is perfect.
ALL TOP SHELF BUILDS - and money well spent

Car starts right up
Idles nice
Runs smooth at 60 even 65 highway

Issue is when I get on it - like up a hill or just for heck of it - upper RPMs it breaks up.

Where so I start?
Condenser?
Stop break?
or???

BTW - I already changed fuel filter....which is just before electric pump...

38bill · 07-08-2019, 07:17 PM

Mine will do that if I really stand on it and rev it up between shifts. I pretty sure mine is a float or fuel pressure issue causing it to lean out.

tubman · 07-08-2019, 07:27 PM

Do you have any idea of the RPM you are turning when it starts breaking up? I have seen 5500 from my 258" 8BA with a MAX-1 cam, Isky 185 springs, prepped Edmunds heads, a Mallory dual point, and one 2G carburetor. I don't think I'd want to see more than that. The engine was also balanced when it was built.

adileo · 07-08-2019, 07:43 PM

No I don’t. no tach. I’d guess 3500-4000 but that’s just a guess. I’m all stock with exception of what I’ve mentioned above. Build is 30+ years. If they zero’d odometer at build I’m reading 37,000 miles, of which I put 11k

drolston · 07-08-2019, 09:16 PM

The missing occurs under conditions of high rpm and low vacuum, which is also the occasion of high cylinder compression pressure. That raises the voltage needed to jump the plug gap. Maybe your spark is not strong enough to jump the gap at those pressures. Whatever in the ignition is 30 years old would be suspect, especially the ignition wires. Maybe the coil.

Tinker · 07-09-2019, 12:39 AM

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Condenser would be my first guess. But I don't know. great thread. Seems fuel related. Following.

adileo · 07-09-2019, 05:34 AM

Thanks guys all good advise. I’ll check plugs and wire connections. Then replace condenser it’s a cheap fix if that it.

Gonna check choke rod too maybe that’s it. I have K&N air filters cleaned end of winter but will check that as well.

G.M. · 07-09-2019, 06:22 AM

Sounds like weak point springs. G.M.

tinkirk · 07-09-2019, 07:18 AM

Quote:

Originally Posted by adileo

My 39 coupe - EAB engine - all listed below 2- closer to 3 years old
dual Edlebrock 94s built by Charlie
Disto built to 11A by Bubba
Coil built by Skip
Radiator pulled this winter and had it cleaned. Car @ 95F runs no higher than 190 which to me is perfect.
ALL TOP SHELF BUILDS - and money well spent

Car starts right up
Idles nice
Runs smooth at 60 even 65 highway

Issue is when I get on it - like up a hill or just for heck of it - upper RPMs it breaks up.

Where so I start?
Condenser?
Stop break?
or???

BTW - I already changed fuel filter....which is just before electric pump...

my experience is that if it starts coughing under full throttle it's getting to much fuel or not enough timing
if it start's to lay down it's not enough fuel or to much timing

Just be careful with the timing!!

tinkirk

oldford2 · 07-09-2019, 12:00 PM

Quote:

Originally Posted by G.M.

Sounds like weak point springs. G.M.

I don't know anything about Bubba's dizzies. But as GM says that on original distributors, weak springs will cause "points float". Skipping/missing at high RPM
John

JSeery · 07-09-2019, 12:04 PM

One of the reasons for dual points was better coil saturation at high rpms. Might be worth putting it on a machine and see what is going on.

adileo · 07-09-2019, 12:09 PM

Thanks Bubba Guaranteed for life. But knowing his situation, I hope it’s one of the other suggestions

supereal · 07-09-2019, 12:34 PM

We run all distributors on our Sun machine to be sure the points retain contact. It plainly shows on the strobe. The quality of the point sets being sold today is very low. Of the last six we checked, four were unusable. As said above, point "float" is a likely problem. Another is low dwell, preventing full saturation of the coil. A weak condenser will also do it. Find a shop with a machine.

tubman · 07-09-2019, 01:09 PM

I had the points out of my Mallory dual point a couple of days ago to check for wear and pitting, and they seemed to me to have a lot more spring pressure than some ordinary point sets. I'm wondering if the "points float" guys might be on to something. It might have just been my imagination, but I noticed right away that they seemed real stiff.

07-08-2019, 06:01 PM	#1
adileo Senior Member Join Date: Jun 2014 Location: New Jersey Posts: 1,772	high rpms breaking up My 39 coupe - EAB engine - all listed below 2- closer to 3 years old dual Edlebrock 94s built by Charlie Disto built to 11A by Bubba Coil built by Skip Radiator pulled this winter and had it cleaned. Car @ 95F runs no higher than 190 which to me is perfect. ALL TOP SHELF BUILDS - and money well spent Car starts right up Idles nice Runs smooth at 60 even 65 highway Issue is when I get on it - like up a hill or just for heck of it - upper RPMs it breaks up. Where so I start? Condenser? Stop break? or??? BTW - I already changed fuel filter....which is just before electric pump... __________________ Thanks Andy 1952 F1

07-08-2019, 07:17 PM	#2
38bill Senior Member Join Date: Apr 2014 Location: Minnesota Posts: 1,166	Re: high rpms breaking up Mine will do that if I really stand on it and rev it up between shifts. I pretty sure mine is a float or fuel pressure issue causing it to lean out.

07-08-2019, 07:27 PM	#3
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,312	Re: high rpms breaking up Do you have any idea of the RPM you are turning when it starts breaking up? I have seen 5500 from my 258" 8BA with a MAX-1 cam, Isky 185 springs, prepped Edmunds heads, a Mallory dual point, and one 2G carburetor. I don't think I'd want to see more than that. The engine was also balanced when it was built.

07-08-2019, 07:43 PM	#4
adileo Senior Member Join Date: Jun 2014 Location: New Jersey Posts: 1,772	Re: high rpms breaking up No I don’t. no tach. I’d guess 3500-4000 but that’s just a guess. I’m all stock with exception of what I’ve mentioned above. Build is 30+ years. If they zero’d odometer at build I’m reading 37,000 miles, of which I put 11k __________________ Thanks Andy 1952 F1

07-08-2019, 09:16 PM	#5
drolston Senior Member Join Date: Jun 2014 Location: Williamsburg, VA Posts: 1,627	Re: high rpms breaking up The missing occurs under conditions of high rpm and low vacuum, which is also the occasion of high cylinder compression pressure. That raises the voltage needed to jump the plug gap. Maybe your spark is not strong enough to jump the gap at those pressures. Whatever in the ignition is 30 years old would be suspect, especially the ignition wires. Maybe the coil.

07-09-2019, 12:39 AM	#6
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: high rpms breaking up Sponsored Links (Register now to hide all advertisements) Condenser would be my first guess. But I don't know. great thread. Seems fuel related. Following.

07-09-2019, 05:34 AM	#7
adileo Senior Member Join Date: Jun 2014 Location: New Jersey Posts: 1,772	Re: high rpms breaking up Thanks guys all good advise. I’ll check plugs and wire connections. Then replace condenser it’s a cheap fix if that it. Gonna check choke rod too maybe that’s it. I have K&N air filters cleaned end of winter but will check that as well. __________________ Thanks Andy 1952 F1

07-09-2019, 06:22 AM	#8
G.M. Senior Member Join Date: May 2010 Location: Florida and Penna. Posts: 4,471	Re: high rpms breaking up Sounds like weak point springs. G.M. __________________ www.fordcollector.com

07-09-2019, 12:04 PM	#11
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: high rpms breaking up One of the reasons for dual points was better coil saturation at high rpms. Might be worth putting it on a machine and see what is going on.

07-09-2019, 12:09 PM	#12
adileo Senior Member Join Date: Jun 2014 Location: New Jersey Posts: 1,772	Re: high rpms breaking up Thanks Bubba Guaranteed for life. But knowing his situation, I hope it’s one of the other suggestions __________________ Thanks Andy 1952 F1

07-09-2019, 12:34 PM	#13
supereal Senior Member Join Date: Jul 2014 Location: Iowa Posts: 1,634	Re: high rpms breaking up We run all distributors on our Sun machine to be sure the points retain contact. It plainly shows on the strobe. The quality of the point sets being sold today is very low. Of the last six we checked, four were unusable. As said above, point "float" is a likely problem. Another is low dwell, preventing full saturation of the coil. A weak condenser will also do it. Find a shop with a machine.

07-09-2019, 01:09 PM	#14
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,312	Re: high rpms breaking up I had the points out of my Mallory dual point a couple of days ago to check for wear and pitting, and they seemed to me to have a lot more spring pressure than some ordinary point sets. I'm wondering if the "points float" guys might be on to something. It might have just been my imagination, but I noticed right away that they seemed real stiff.