Ignition Issues, Crab distributor

[petehoovie]

Originally Posted by Ziggster

By some miracle, as I’m playing around with the machine, and with the crab distributor mounted, I got the strobe lights and tach to work. If anyone knows how to use this thing, please PM as the manual I purchased for it is almost useless.

[glennpm]

Originally Posted by ford38v8

Glenn, that sounds perfectly reasonable, but in practice, dunno if even possible to get that degree of rotational accuracy on those screws while bent over into the hot engine compartment! At that point I’d be reluctant to disturb what’s already a good thing!

Yeah I hear you!
Not that hard to do though. Wait until the engine cools down and adjust then. I have an old Craftsman screwdriver that has flutes on the handle. Makes it way to note the amount of rotation. Bottom line though is that it probably makes little to no difference but why not? :-)

[BIG KEV]

Originally Posted by petehoovie

Thats one good looking distributor machine! Love the art deco look of it.

[kingeak]

Was having issues with my 37. Thought it was carb / fuel pump related, but it may have been intermittent spark from my corroded rotor tab. Popped off the crab style dist cap and noticed soot on rotor tab and greenish corrosion on underside of crab dist cap. Cleaned up both and (fingers crossed) didn’t have any start up issues, even after heat soak from setting after a drive.

PS - a buddy recommended investing in a vacuum gauge. Solid investment!

Here’s my result on the 37.

https://youtu.be/3siEFzH5Lmo?feature=shared

[BIG KEV]

Well. Had my fingers crossed. Drove her this monring with bad results. Uggg

20 min in. Pulled up to a stop sign and she died. She did restart. Drove down the road and had some doubts so decided to backroad it to the house. Put her on fast idle she runs and doesn’t die. Pushed the choke all the way in to get off fast idle. Pulled up to a stop sign. She stumbles. Give her some gas to try to muscle through. Died in intersection. No restart. Pushed her out of intersection. Let it sit for 2 min. She fired up. Got to the house. Pulled in driveway and she was ok but not great. Checked spark by grounding screwdriver method. Spark was jumping 1/2”. Adjusted the mixture a smidge. Then though huh. Why not make it die and try to restart. 1/4 turn in and she stumbled. 1/4 more and she died.

So checked spark again. Weak when cranking. Maybe jumped the tester 1/4” not all the time. She finally fired 2 min later. Once it started the spark went from small gap to hitting hard like normal.

Ignition coil was hot. 2 second touch is about max. It is an internal regulated coil but eh.

Checked dwell again. 36 deg of dwell.

2 things I am thinking.

Restart issue. Power to the inside of the car comes off starter solenoid. Going to move it back to battery direct feed. Voltage drop on hot coil probably hurts more than helps.


Secondly. Coming up to a stop or making a hard turn says carb issue. Making a hard turn she will start popping and then clear out once you are on the gas straightening out.

[glennpm]

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Try another condensor.

Fuel bowl level?

[Ziggster]

Which coil are you now running? I thought you sorted the issue of the hot coil? Some pics of the carb(s) with fuel lines might help. You mention copper fuel lines and maybe going to rubber? What configuration do you now have? In my thread about persistent fuel leaks, using copper is not suggested by folks. I know you mention the 97s have been gone through, but when I rebuilt my 94, main shaft was loose on the hsg which is a common issue which leads to vacuum leaks. Is there play in the shaft(s)? I also had continuity issues on my helmet when testing it. Might suggest you check continuity/resistance between all components in the electrical path to ground. My points were closed but had no continuity between the contacts. I adjusted them to ensure I could see the spring side of the contact move while adjusted the fixed contact. I even made sure dist hsg was properly grounded as there is a paper gasket between it and the timing gear cover, and the bolts that secure it to cover require sealant as they pass through the cover, so a good metal to metal contact may be difficult between the hsg and the block. Hope this might help as I feel your pain.

[BIG KEV]

Originally Posted by glennpm

Try another condensor.

Fuel bowl level?

I am on condenser #8, all have tested good to this point, I have a NOS echlin on there right now. The Stock 42 ford one works just as good.

Fuel level was set to 1/2" below top of bowl running with tops off.

Originally Posted by Ziggster

Which coil are you now running? I thought you sorted the issue of the hot coil? Some pics of the carb(s) with fuel lines might help. You mention copper fuel lines and maybe going to rubber? What configuration do you now have? In my thread about persistent fuel leaks, using copper is not suggested by folks. I know you mention the 97s have been gone through, but when I rebuilt my 94, main shaft was loose on the hsg which is a common issue which leads to vacuum leaks. Is there play in the shaft(s)? I also had continuity issues on my helmet when testing it. Might suggest you check continuity/resistance between all components in the electrical path to ground. My points were closed but had no continuity between the contacts. I adjusted them to ensure I could see the spring side of the contact move while adjusted the fixed contact. I even made sure dist hsg was properly grounded as there is a paper gasket between it and the timing gear cover, and the bolts that secure it to cover require sealant as they pass through the cover, so a good metal to metal contact may be difficult between the hsg and the block. Hope this might help as I feel your pain.

Yeah Zig, I thought I had it figured out as well but looks like my change to the autolite plugs brought it back. Maybe I need to run resistor core plugs to cut down amperage?

Still running the internally regulated Bosch Coil.

Never swapped fuel lines, Trying to not do a metric crap ton of changes at one time. Since this thing has really eaten my lunch for 6 months now.


I am going to retest continuity again today probably.

I had cleaned off the bolts when bolting the dizzy back on the block, the distributor is clean and clear, it was showing less than .01 ohm from battery to the distributor housing resistance last time I checked.

I have 4 gauge battery to the torque tube mount factory ground location, then I daisy chain from there to the frame with another 4 gauge wire. From the engine I also ground to the body as well. All clean metal contacts, cleaned bolt threads inside and out.

Ill report what I find on continuity and post a few pics from the handheld device.

Thanks guys.

[glennpm]

You’re doing the right thing on checking resistance. It’s making the coil hot.
Have you measured the coil’s resistance?

[glennpm]

Plug wires?

[38 coupe]

I helped a local club member with similar issues on her 41 pickup that had been converted to 12V. She was running a Bosch blue coil that would get hot and break down. I ended up using a Standard Motor Products UC12 coil with an external resistor mounted on the coil bracket, that solved the coil break down issue.

[BIG KEV]

Originally Posted by glennpm

You’re doing the right thing on checking resistance. It’s making the coil hot.
Have you measured the coil’s resistance?

Thanks. Yes. 3.7 ohms.

Plug wires are solid core translucent.
Nothing weird on those. Last time I checked em they were 0.0 ohm.

[BIG KEV]

Originally Posted by 38 coupe

I helped a local club member with similar issues on her 41 pickup that had been converted to 12V. She was running a Bosch blue coil that would get hot and break down. I ended up using a Standard Motor Products UC12 coil with an external resistor mounted on the coil bracket, that solved the coil break down issue.

Thanks, you have me thinking of just going back to the ballast resistor with the UC12 coil I have here.

I rewired the ignition feed to the cab off the battery, and then my small stud on the starter broke a wire inside of it, so now I have to do a starter. I have a 6v I may do the 12v field coil on and just carry a bendix around like I used to with the bangers.

[petehoovie]

Originally Posted by BIG KEV

Thanks. Yes. 3.7 ohms.

Plug wires are solid core translucent.
Nothing weird on those. Last time I checked em they were 0.0 ohm.

[BIG KEV]

Originally Posted by glennpm

You’re doing the right thing on checking resistance. It’s making the coil hot.
Have you measured the coil’s resistance?

Well did continuity checks through everything. Distributor to the battery read 0.1 to 0.2 ohms on that check. On regular ohm setting got 0.02

Those same readings were from the body as well as to the motor in various places and bolts.

I went ahead and swapped back out to the 1.7 ohm Standard UC12t Coil with the ballast resistor. Watched voltage out of the ballast resistor running, 6.4 volts at idle, rev it up and get almost 8 out of it with the alt pumping up to 14.4 volts.

Went ahead and went to my old starter with the firewall mounted solenoid, I have a 4 wire solenoid, So I am running the ignition terminal off it to bypass the ballast resistor. Holy hell hit the starter it pops off now not even 1/8 turn of the crank.

Only time and testing will tell.

[glennpm]

Originally Posted by BIG KEV

o I am running the ignition terminal off it to bypass the ballast resistor. Holy hell hit the starter it pops off now not even 1/8 turn of the crank.

Great news!

When I was having similar trouble as yours a couple of years ago which turned out to be the condensor but also one of the blue Beru coils that got wicked hot. I run a 12V system. I also wired up an intermittent or momentary push button switch that bypassed my ballast resistor for starting and it worked well. I still have it wired up but no longer need it with my coil change.

Now with a good condensor, Mallory coil and resistor, I seldom use it.

I now have a Mallory coil and ballast resistor. The cold ohm readings are:

- Mallory coil = 1.3 Ω
- Ballast resistor under dash = 1.3 Ω
- Total = 2.6 Ω
I = 14V / 2.6 Ω = 5.38 amps

[BIG KEV]

Few thermal images I took the other day after a 30 min drive, high 80s outside, motor never went over 160. I may need to relocate the coil mount to the plug wire look ultimately. Funny how an 8ba has em on the head with zero issues. Maybe I am overthinking it. Carbs are staying cooler with the phenolic spacers for sure.

I did buy a new multimeter, checked capacitance on the condensers I had, the small ones are about .24 uf, and the bigger longer ford orig. and the napa I have both are .32 uf. The motor seems to like the .32uf condensers.

IMG_9048.jpg
IMG_9054.jpg

[tubman]

Excellent diagnostic work; the thermal images in particular are quite enlightening. I have a question about the condenser ratings that you have given. They may be correct, and from my experience the engine will probably run fine at those values. However, they are about 10 times the value of commercially available units. I have found that most current condensers are in the .20 to .40 microfarad (µF) range (the original Mallory "Trash Cans" were rated at .36µF). That both of the ones you tested are a factor of 10 larger is curious. Are you using the proper scale on the multimeter? This is in no way a criticism of what you have done, but I want to make sure we are talking about the same thing, as in my position I need to know as much about these things as I can.

BTW, the uf symbol is the same as the fancy µF.

[BIG KEV]

Originally Posted by tubman

Excellent diagnostic work; the thermal images in particular are quite enlightening. I have a question about the condenser ratings that you have given. They may be correct, and from my experience the engine will probably run fine at those values. However, they are about 10 times the value of commercially available units. I have found that most current condensers are in the .20 to .40 microfarad (µF) range (the original Mallory "Trash Cans" were rated at .36µF). That both of the ones you tested are a factor of 10 larger is curious. Are you using the proper scale on the multimeter? This is in no way a criticism of what you have done, but I want to make sure we are talking about the same thing, as in my position I need to know as much about these things as I can.

BTW, the uf symbol is the same as the fancy µF.

Opps, just a screw up in my decimal placement.

Nice catch. I fixed the post.

[Bored&Stroked]

I run Vertex magneto condensers . . . expensive, but they have never let me down. Also, I have a condenser "tester" - that charges them, checks the fly-back, etc.. You really can't test a condenser with just a multimeter.

Here is what I run on all my Harman Collins dual coils - have never had one fail:

https://fuelinjectionent.myshopify.c...36uf-condenser