flat head
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flat head
I have the 239 flathead and have installed so far the new fuel pump and carb. At that point I got the truck to start. It seems to not be running on all cylinders, when we pull wires strange things happen. We pull #6 and ground the wire to block and the engines seems to run better, the reves come up. So we thought we would change out the distributor and wires. I moved to the MSD Pro billet Ready to run distributor and wires. We used the trick with oil and a tube to make sure we were TDC on plug one. The engine one again started with same problems. # 6 pulled seem to make the motor run on more cylinders. We were able to pull 1, 2, 3 and 4 while engine was running with no affect to how it was running. When we pull #8 the engine does drop like it was running on 8. We then pulled 8 and 6 and tried to start motor and it started. Im running out of ideas and thought I would see if you have any we can try. By chance do you know anyone in Calgary that knows much about the flathead? The other thing is we are seeing a lot of raw gas dripping from the carb and the odor of raw gas. Any Ideas would be so helpful Thanks Dave
Lead Driver
Joined: Oct 1999
Posts: 6,765
Likes: 547
From: Kalispell, MT
Ah, there you are.. I posted a short msg to the welcome post.
We'll need some additional details. What series flathead - is it safe to assume it's an 8BA/8RT? What is it in? And what modifications have been made to it? Are your grounds and ignition system in great working condition? 12 or 6V?
Multiple issues: Fuel pressure is too high OR more likely the float is set too high.
Miss-fire. You've probably got crossfiring going on with your plug wires. Flatheads will run when nothing else will - that's why you can pull wires and it'll keep running. Wires 1 & 2 and 6 & 8 are particularly suseptible to this problem because they fire in sequence to each other.
Are you familiar with Ford's cylinder numbering - passenger side numbers front to back 1234? Driver's side is 5678 front to back. The firing order should be 15486372 Without knowing what all you've done I'd suggest your first step would be to install new top grade plug wires. 2nd, isolate them from each other.
Welcome by the way - I can provide a ton of links where you can find specific help you need. Do you have a shop manual? When we know the answers in bold type above we'll be able to be a bit more specific.
We'll need some additional details. What series flathead - is it safe to assume it's an 8BA/8RT? What is it in? And what modifications have been made to it? Are your grounds and ignition system in great working condition? 12 or 6V?
Multiple issues: Fuel pressure is too high OR more likely the float is set too high.
Miss-fire. You've probably got crossfiring going on with your plug wires. Flatheads will run when nothing else will - that's why you can pull wires and it'll keep running. Wires 1 & 2 and 6 & 8 are particularly suseptible to this problem because they fire in sequence to each other.
Are you familiar with Ford's cylinder numbering - passenger side numbers front to back 1234? Driver's side is 5678 front to back. The firing order should be 15486372 Without knowing what all you've done I'd suggest your first step would be to install new top grade plug wires. 2nd, isolate them from each other.
Welcome by the way - I can provide a ton of links where you can find specific help you need. Do you have a shop manual? When we know the answers in bold type above we'll be able to be a bit more specific.
Last edited by mtflat; Nov 28, 2005 at 09:16 AM.
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yes its a 8ba
i believe i have the wires on in the correct order
numbering from front passenger side 1-4
drivers side 5-8
any idea why pulling 6 would make the motor run better?
I will check the float
It is a new stock fuel pump
the carb is a new rebuild
the firing order i have is 15486372 one being at the bottom of distributor
i believe i have the wires on in the correct order
numbering from front passenger side 1-4
drivers side 5-8
any idea why pulling 6 would make the motor run better?
I will check the float
It is a new stock fuel pump
the carb is a new rebuild
the firing order i have is 15486372 one being at the bottom of distributor
Lead Driver
Joined: Oct 1999
Posts: 6,765
Likes: 547
From: Kalispell, MT
Hi Dave,
I'd say you can rule out fuel pressure with a stock pump. Rebuilt or not I'd check the float level. Did it come with a card showing what float level should be? For a Holley 94 take the top off (5 screws and some linkage) turn the top over so the float is resting in the closed position. It should measure right around 1 5'16" from the bottom of the float to the flat machined surface. Bend the tab on the hinge of the float to adjust.
If you've had a backfire thru the carb since you installed it, the power valve has probably blown and that'll drain the gas from the bowl into the intake every time you shut it down.
Keep in touch and we'll get it sorted out. These are fairly easy.
Tim
I'd say you can rule out fuel pressure with a stock pump. Rebuilt or not I'd check the float level. Did it come with a card showing what float level should be? For a Holley 94 take the top off (5 screws and some linkage) turn the top over so the float is resting in the closed position. It should measure right around 1 5'16" from the bottom of the float to the flat machined surface. Bend the tab on the hinge of the float to adjust.
If you've had a backfire thru the carb since you installed it, the power valve has probably blown and that'll drain the gas from the bowl into the intake every time you shut it down.
Keep in touch and we'll get it sorted out. These are fairly easy.
Tim
Last edited by mtflat; Nov 28, 2005 at 09:35 AM.
Lead Driver
Joined: Oct 1999
Posts: 6,765
Likes: 547
From: Kalispell, MT
I'd say from your description 6 and 8 are crossfiring. Try isolating the wires with plastic loom and see if that helps. It's also possible your timing is off a little - try turning the dist a bit (ccw)to give a little more advance while it's running and see if it settles down. If not, decrease the advance - flatheads don't like as much advance as the OHVs.
Also make sure your grounds are good from battery to cab, cab to engine, cab to frame and starter to block. Especially if 6V. And make sure all your contacts are clean and tight.
Out of curiosity, what plugs are you using?
Your problems sounds much like my 48 did when I first got it going. Take heart, the longer you run it the better it will get.
Also make sure your grounds are good from battery to cab, cab to engine, cab to frame and starter to block. Especially if 6V. And make sure all your contacts are clean and tight.
Out of curiosity, what plugs are you using?
Your problems sounds much like my 48 did when I first got it going. Take heart, the longer you run it the better it will get.
Last edited by mtflat; Nov 28, 2005 at 09:48 AM.
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i have coverted to 12 volt
i have all wires numvered at both ends as to not install them in the wrong order.
This motor had not been run in 25 years and had been rebuilt by ford about 1000 miles earlier
I am using the champion plugs recomended
i have all wires numvered at both ends as to not install them in the wrong order.
This motor had not been run in 25 years and had been rebuilt by ford about 1000 miles earlier
I am using the champion plugs recomended
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Lead Driver
Joined: Oct 1999
Posts: 6,765
Likes: 547
From: Kalispell, MT
Have you tried Marvel Mystery Oil or equivalent in the crank case, gas and in the cylinders? You could have valves sticking a little - that'll make it run real ragged.
Also, I've never had any luck with Champions plugs in a Ford. I only use Autolite 216.
Also are you running an ignition resistor in your power to the coil or is your coil internally resisted? Make sure your specs are in line with what MSD requires. I'm still using the stock setup.
ps. The forum allows you 1 hour to go back and edit each post. I've added some things to the earlier ones cause I remembered some stuff I should have included. Might go back and check them.
Also, I've never had any luck with Champions plugs in a Ford. I only use Autolite 216.
Also are you running an ignition resistor in your power to the coil or is your coil internally resisted? Make sure your specs are in line with what MSD requires. I'm still using the stock setup.
ps. The forum allows you 1 hour to go back and edit each post. I've added some things to the earlier ones cause I remembered some stuff I should have included. Might go back and check them.
Fleet Owner
Joined: Jul 2004
Posts: 27,283
Likes: 1,046
From: NM
If one whole bank is not working (i.e., pulling those plugs doesn't make a difference), I'd suspect the jet or idle mixture circuit is plugged or turned all the way in on that side. Put both idle screws at 1.5 turns out from bottom.
You may be damaging an otherwise good motor if you are having to hold the throttle wide open to keep it running. You should do some investigation to eliminate the usual culprits.
You may be damaging an otherwise good motor if you are having to hold the throttle wide open to keep it running. You should do some investigation to eliminate the usual culprits.
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Joined: Jul 2001
Posts: 2,119
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From: Southern New Hampshire
Before you hurt the engine do a compression test. More than likely you have a few valves stuck open and the test will tell you which ones.
Then spray a little ATF down a plug hole on to the valve stems; push the valve down with a screwdriver. Keep turning the engine over with no ignition untill the valves are free.
When you converted to 12V I hope you reversed the leads to the new coil.
Then spray a little ATF down a plug hole on to the valve stems; push the valve down with a screwdriver. Keep turning the engine over with no ignition untill the valves are free.
When you converted to 12V I hope you reversed the leads to the new coil.