|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
|
05-06-2020, 03:21 AM | #1 |
Senior Member
Join Date: May 2010
Location: Manawatu, New Zealand
Posts: 1,416
|
Help Me -before I go mad
Its not often I'm completely lost but this is it
I have been chasing an intermittent miss in the 34 which I can't find Completely stock set up 6V Mike Driscoll Distributor Skip Haney Coil Uncle Max rebuilt Stromberg 48 Its a long story but I have completely hit a brick wall and I really need some help. I have had an intermittent miss for last 4 months intially was just a slight stumble at speed but has got progressively worse. A couple of months or so ago after 5 minutes driving the car began to buck and miss and even with full gas 30 mph was the most it would go As I slowed down to pull over died completely and would not start . My wife towed me home. Found I had 4.3 Volts to the coil but absolutely no spark . Ok That's easy Coil or condenser. Since I have no way of testing the coil and on a 34 Taking the coil out is the easiest way to change the condensor I changed out both with a condenser that tested fine and a new Skip Haney Coil . Started right up but still continues to miss. Slightly lumpy at idle . but good spark to the plugs I have changed the condenser twice . I have changed the Distrib Caps , I've changed the plugs . I have checked and rechecked Yesterday It did same thing (in the same place) after 5 minutes on load missing badly jerking and jumping and max 25mph at full throttle I pulled the choke didn't improve but back fired . After about 4 mins of this it came right . Tonight in the garage I have run it in the dark no shorts anywhere that I can see. I removed the plug leads and I have A nice juicy spark that jumps at least 1/4 inch to each plug. Suggesting to me that the ignition circuits are ok and the condenser/Coil is good I did notice some garbage in the fuel pump bowl (Mike Driscoll rebuilt Fuel pump with a bowl) I have installed a fuel filter and Cleaned out the carb and all the carb lines even tried running my spare 97 and no improvement. The only thing I can think of now is the plug leads or perhaps the surpressors on the leads for the radio -However I just can't see that multiple leads would all fail together -and then come right. Have no idea what to do next Help -Karl
__________________
Such a fine sight to see-Its a Girl, My Lord, in a Flatbed Ford slowin' down to take a look at me. |
05-06-2020, 03:38 AM | #2 |
Senior Member
Join Date: May 2010
Location: Oamaru, New Zealand
Posts: 419
|
Re: Help Me -before I go mad
Sounds like might be the rotor....old originals do go bad, new repros are suspect. 4.3 at the coil is low enough, what is the generator charging? I don't know, but are Skips coils built to be 4.3 volts or 6? Just a thought.
|
Sponsored Links (Register now to hide all advertisements) |
|
05-06-2020, 04:58 AM | #3 |
Senior Member
Join Date: May 2010
Location: Solihull, England.
Posts: 8,752
|
Re: Help Me -before I go mad
I'd also be looking at the HT side of the ignition. The HT loads need to be low as the spark will try and find the path of least resistance. If you have resistor plug caps, ditch them. Make sure your plug gaps are at .025" no wider. On a helmet, the most likely culprit is the rotor. A new rotor, along with losing the resistor caps will probably fix it. You can put a couple of layers of shrink tube on the distributor shaft to help stop the rotor/shaft spark leak path.
My experience is mostly with the crab distributor but all the same things apply. Mart. |
05-06-2020, 05:27 AM | #4 |
Senior Member
Join Date: Oct 2016
Posts: 250
|
Re: Help Me -before I go mad
Agree, it’s likely the rotor. There is one more thing you can check on the helmet; the screw that sets the advance on the breaker plate. I had a similar situation and found the screw was stripped, allowing the breaker plate to move slightly. Sometimes it was fine, other times it wasn’t. While checking the rotor, be sure to check that screw as well.
|
05-06-2020, 05:31 AM | #5 |
Senior Member
Join Date: May 2010
Posts: 4,751
|
Re: Help Me -before I go mad
Remove the radio condenser at the ignition coil and check again.
|
05-06-2020, 05:59 AM | #6 |
Senior Member
Join Date: May 2010
Location: FP, NJ
Posts: 2,770
|
Re: Help Me -before I go mad
Sponsored Links (Register now to hide all advertisements)
__________________
Don't never get rid of nuthin! |
05-06-2020, 06:35 AM | #7 |
Senior Member
Join Date: May 2010
Location: Auburn, MA
Posts: 2,106
|
Re: Help Me -before I go mad
Check your ignition switch and wiring to the coil. A loose or bad connection can cause what you describe. It might be getting worse as it heats up. Also if you have one of those resistors that varies with heat I'd look at that too.
__________________
“The technique of infamy is to start two lies at once and get people arguing heatedly over which is true.” ~ Ezra Pound |
05-06-2020, 06:48 AM | #8 |
Senior Member
Join Date: Jun 2010
Location: St Croix Falls WI
Posts: 2,080
|
Re: Help Me -before I go mad
I have used Champion UD16 plugs for testing spark .
They have hollow stems and you can see the spark when running . Easy to see any weak-dead ones . Also easy to see if any intermittent spark . On a completely different note my 34 was cutting out and losing power . Couldn't find any obvious issues until loosening the gas cap cured it . Never had that issue before and it turned out to be a plugged vent on top of the tank . |
05-06-2020, 06:58 AM | #9 |
Senior Member
Join Date: May 2010
Location: Ashland KY
Posts: 1,159
|
Re: Help Me -before I go mad
Ever check for plugged exhaust!
__________________
DON P |
05-06-2020, 07:53 AM | #10 |
Senior Member
Join Date: Dec 2013
Location: Waxahachie, Texas
Posts: 949
|
Re: Help Me -before I go mad
I'm sure you've checked it, but you mentioned you saw some trash in the fuel bowl. Are you sure you have good, strong fuel flow with no restrictions? I have a '31 Model A that was acting the same way as you describe; driving along smoothly then started bucking, backfiring, spitting, and finally dies. The trouble was trash, rust particles blocking good, strong fuel flow to the carb. I had to install a fuel sediment bowl to strain out the rusty stuff. Once I got the fuel to flow properly, it runs fine.
|
05-06-2020, 08:10 AM | #11 |
Senior Member
Join Date: May 2010
Location: East Hartford, Ct
Posts: 5,898
|
Re: Help Me -before I go mad
Have seen similar conditions that were due to a cracked cork sediment bowl gasket (was sucking air not fuel)
__________________
DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES |
05-06-2020, 08:28 AM | #12 |
Senior Member
Join Date: May 2010
Location: upstate SC
Posts: 2,963
|
Re: Help Me -before I go mad
remove/change the rotor, while you are at it insulate the shaft with shrink tubing or electrical tape
|
05-06-2020, 09:34 AM | #13 |
Senior Member
Join Date: May 2010
Location: Snohomish,WA
Posts: 1,030
|
Re: Help Me -before I go mad
|
05-06-2020, 10:31 AM | #14 |
Senior Member
Join Date: May 2010
Location: Jacksonville FL
Posts: 1,137
|
Re: Help Me -before I go mad
This is a worn shaft and that's masking tape ... all used to illustrate where the shrink tubing or elec tape would go.
distshaft.jpg
__________________
"Remember that when it comes to intelligence, half of all of us are below average." |
05-06-2020, 10:38 AM | #15 |
Senior Member
|
Re: Help Me -before I go mad
The Coil Wire can drive you crazy. Do change it and test drive I seen that before. You want a solid wire not carbon wire.
|
05-06-2020, 11:58 AM | #16 | |
Senior Member
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 10,317
|
Re: Help Me -before I go mad
Quote:
Not that this has any bearing n the O/P's problem, since the '34's had an integral coil, but I thought I'd mention it anyway, on the chance that he has installed an adapter and remote coil. |
|
05-06-2020, 02:14 PM | #17 | |
Senior Member
Join Date: May 2010
Location: Snohomish,WA
Posts: 1,030
|
Re: Help Me -before I go mad
Quote:
Thank you. It's been several years since I had my distributor apart. I had forgotten that the shaft was that way |
|
05-06-2020, 09:19 AM | #18 |
Senior Member
Join Date: Oct 2011
Location: Shelton, WA
Posts: 3,800
|
Re: Help Me -before I go mad
One more thing to check would be swap out the resister. It could be broken but making a connection enough to run but when it heats up breaks the circuit to the coil. Get a jumper wire with alligator clips and hot wire the coil from the hot side of the starter switch at the bottom of your steering column and see if it runs fine. That would tell you if it was the switch or resistor assuming no shorts in any of the wires.
|
05-06-2020, 09:29 AM | #19 |
Senior Member
Join Date: May 2010
Location: Wisconsin, USA
Posts: 9,007
|
Re: Help Me -before I go mad
I had a similar thing occur on a clients '40 a few years back. Pulled my hair out trying to find the culprit. Turned out to be one bad spark plug. Nothing visible amiss and ran perfectly when cold.
In all my years, that was a new one to me.
__________________
"I can explain it for you. However, I can't understand it for you". |
05-06-2020, 11:00 AM | #20 |
Senior Member
Join Date: Jun 2014
Location: Williamsburg, VA
Posts: 1,627
|
Re: Help Me -before I go mad
Definitely not carbon "resistor" ignition cables. The cheap ones are also affected by humidity so that the problem changes with the weather. If you are running the spark plug wires through tubes, you may not be able to see the shorts, even at night. You can use the coil wound wire center ignition cables to for radio suppression without causing spark problems. Be sure to get 7mm spark plug wires, not 9mm, or you will have problems getting them to fit.
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|