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-   -   Who Can Diagnose THIS Total Mystery? Win A Prize? (https://www.fordbarn.com/forum/showthread.php?t=95803)

H. L. Chauvin 01-29-2013 03:25 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

To: sgwilson904

Tuesday afternoon attitude check ???

Gord. B by the bay 01-29-2013 03:55 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

tHE ABOVE suggestions are all good and there are many possibilities alond with the gas Cap not venting, make sure the wire from the coil to the dist. HAS A SOLID WIRE nof the cardon center jobs that are used on the cars today. Give it a try and drive for miles Gord. B by the Bay

sgwilson904 01-29-2013 05:12 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Quote:

Originally Posted by H. L. Chauvin (Post 581223)
To: sgwilson904

Tuesday afternoon attitude check ???

First, H.L., I really appreciated your detailed test idea for proper ground. Today a club pal removed his distributor (known to be working well), we removed mine and replaced it with his (re-setting the timing).

We did notice lots of play in the shaft as we did this, so apparently a recent engine overhaul did not include replacement of the drive gear and related parts which should address too much play? I am getting those various drive gear parts but will meanwhile drive around to see how performance changes with this known-good distributor.

The problem, of course, is that it ran like a champ for 110 miles on a club tour last weekend before the dreaded curse returned, so who knows how far I should drive now to rest assured a good distributor is the answer to my problem. I can say in the 15 miles I drove today after the replacement, it SEEMED to run a slightly cooler and have slightly more power on an incline...but this could be psycho-somatic on MY part, as all of this has already made me crazy. <grin>

Also, when we closely examined MY distributor tat we removed, we noted the condenser wire attachment was SLIGHTLY askew. It is POSSIBLE (but we think not probable) it could have been close enough to cause an intermittent short.

Finally, when we removed the lower plate of mine, we noticed the curved metal piece has been bent at one time and poorly re-straightened. Again, we don't THINK this might have caused a problem but...???

Will drive more tomorrow and provide next update. Stay tuned.

H. L. Chauvin 01-29-2013 06:01 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Thanks for update -- your very much appreciated continued input is an inspiration for all of us to continue to "try" to help.

FWIW, items to consider from past experiences:

A. Model A's can run quite well with very worn distributor bushings because the pressure of the point springs keeps the wobbly distributor shaft & cam to one side thus maintaining close to the same point gap; and,

B. They can run quite well with "lots" of forward & backward play in distributor shaft because the engine camshaft for valves is turning the distributor cam only in one CCW direction.

C. Looking back today at old parts removed from it, my first 1930 Model A Coupe bought in 1958 for $25.00 was so worn out "everywhere", it may be totally unbelievable for some to imagine that it kept going -- luckily, it never left me out on the highway where I had to call to get towed back home -- didn't even have a phone back then.

1937pickup 01-29-2013 06:20 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Put a flathead v8 in it and be done with your problems LOL.

papanick 01-29-2013 08:45 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Check the muffler. Some times when they get old and backup will get hot and block off the exhaust. That would be something to look at.

Good luck with it. It looks like you looked at it all from here. Papanick

Marv 119 01-29-2013 11:17 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

I had a car do the same thing many years ago. We finally figured out the wires on the coil were reversed. Marv

sgwilson904 01-30-2013 06:27 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Update #2, as promised...

With known-working distributor now replacing mine that is suspect, I took it out on a drive today, a 72-mile trip down the Florida coastline to St. Augustine and back. (Outside air temp = 82--with apologies to those of you in the cold country.)

Just is it did in the 110-mile drive before the evil spirit suddenly possessed it last weekend, it seemed to run just fine. Much of the way was a cruise at around 50 mph. Engine temp (water OUT of engine, returning to radiator) stayed generally about 165 but did rise close to 190 when cruising was interrupted but a stop at a light for two minutes or so.

When I left the light after sustained cruise, I did notice some hesitancy and even a lone pop/backfire as I accelerated out of third gear. This was only temporary, however, and it smoothed out within a block or so.

Later, I noticed engine temp rose to 180 at one point during sustained cruise again. Then, after stop at light and resumed 40 mph, temp returned to about 170.

This is much like what happened Sunday, though today, on a shorter drive, it was not as pronounced and seemed to recover which it didn't do last time.

This is not conclusive, I know, but I'm wondering if maybe the distributor might not be the problem? Maybe it's a vapor lock brought on when the engine temp rises, as it is prone to due when stopping at a light after sustained cruise? (as Mike V Message #41 suggested)

When it's hottest, the carburetor is really warm but not so hot I can't touch it and hold fingers on it a bit. Could a faulty/insufficient engine ground be causing the problem, as someone suggested? Where is the ground and how do I check it exactly?

H. L. Chauvin 01-30-2013 07:57 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

1. It was reported some time ago on a rebuild with "all" newly painted parts, that the metal gas line from the sediment bowl/firewall to the engine was incorrectly acting as a ground from the chassis to the engine.



2. Because of the gas line's small amount of metal, (which can be indicated as a small hollow tube in a cross sectional view of same), as opposed to a large solid battery grounding cable with more metal, the small gas line was heating, thus causing a rare case of vapor lock.



3. When some owners experience grounding problems, (mainly because of fresh paint acting as electrical insulation), they provide a separate ground to the engine in lieu of relying solely on the original ground strap from the battery to the chassis, then from the chassis to the engine -- especially when they do not have metal pans on both sides of the engine.



4. If you would add a battery grounding strap from bare metal on the chassis to bare metal on a starter bolt, you would eliminate this reported "rare" vapor lock condition; or, you could try to implement paragraph 5. of message no. 136 above to elinimate this gas line grounding condition.

5. If one chokes an engine & it helps the engine to run a little better, this is most likely a fuel problem; & maybe in this rare case, the "fuel" problem "may" caused by "electrical" heat which causes vapor lock.

6. I did not think the other distributor would make a difference because of what appears to be intermittent fuel starvation.

Keep reporting your experiences -- it will be something simple.

sgwilson904 01-30-2013 08:25 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

H.L., I understand the concept but if the fuel line is serving as a ground and thus heating up, why doesn't the problem occur during a sustained cruise situation instead of just after a long cruise followed by a start-up from a traffic light?

Mike V. Florida 01-30-2013 08:36 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Quote:

Originally Posted by sgwilson904 (Post 582023)
H.L., I understand the concept but if the fuel line is serving as a ground and thus heating up, why doesn't the problem occur during a sustained cruise situation instead of just after a long cruise followed by a start-up from a traffic light?

Steady "fast" flow of fuel through the fuel line and Air blowing through the engine compartment cooling the line at cruise.

Slow fuel flow at idle and no air blowing through the engine compartment at idle.

AL in NY 01-30-2013 10:32 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

sgwilson904, is it possible that the performance (for lack of a better word) differences between the before/after distributor change may be due to a difference in the initial timing? Just my 2 cents.

H. L. Chauvin 01-30-2013 10:36 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

This gas line acting as a ground "could" also be a reason why your carburetor is getting warm -- i.e., the carburetor could act like a heat sink at the end of the hot fuel line.

Nothing amazes me with what people find & learn while driving Model A's.

Model A experts can be thought of as people who decide to quit learning.

40 Deluxe 01-31-2013 12:04 AM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Really, if the fuel line is indeed serving as a ground circuit, how could it possibly get hot enough to cause vapor lock?! Ignition draw is not likely to be over 5 amps or so; the generator may be charging at the rate of 10-15 amps; hitting the brakes may momentarily draw another 5 or so amps for the stoplight. NOT enough to even slightly warm that gas line! There's more metal in that line than in the wire that feeds the entire electrical system (other than starter)!

H. L. Chauvin 01-31-2013 02:49 AM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Hi 4o Deluxe,

Even though hearing of vapor lock, & beleiving it can exists, I have never had a vehicle that could produce vapor lock in our climate.

As such, only reporting what was previously reported from previous intelligent experiences in order to help this guy resolve what so far has "not" yet been resolved.

Coupled with the manifold/exhaust heat experience mentioned in message no. 139 above, appears this is what was experienced & reported about heated fuel on 06-05-2012 at 09:35 a.m.

Vapor Lock --or vapor in a fuel line
I don't know if this applies to any or all other folks, but yesterday I fielded a phone call from someone who described some symtoms like everyone has been describing wanting some tech advice. After thinking about it last night I e-mailed him early this morning for him to call me. On a hunch based on some other feedback he was giving me I suggested that he leave the ignition switch off and while reaching across the engine, engage the starter and allow it to spin for 20 or 30 rounds with one hand while touching the fuel line with another. He called me back and said it didn't even spin 10 rounds before the fuel line got hot enough to burn his hand.

As I explained to him, he has a ground issue. My initial thinking is if the fuel line is carrying the current, then is it "preheating" the fuel in the line enough to create a vapor? Maybe that would explain how someone has 3 cars using the same fuel and swapping carburetors does not make a difference for them. Maybe that would explain how the use of engine pans can cure the problem?? While this may not be the cure in every case, I believe it is a contributing factor to one person's issues.

Carry on............. :rolleyes:

.

__________________
.

BRENT in 10-uh-C




In my opinion it is a safety hazard driving in traffic with a stalling car & the quicker this gentleman can determine the problem, the safer his entire family will be.

Any suggestions?

1931 flamingo 01-31-2013 10:49 AM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Why not try by-passing the fuel tank. Mount a container (hang/secure from the radiator rods), run a line directlt to the carb, no filter and go for a ride. JMO
Paul in CT.

noboD 01-31-2013 01:14 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Just reading here. SO does the engine actually shut off when this happens or does it just run so porly you can't drive? In the time it takes to fix itself have you taken readings with a infrared temp on the ground cable, fuel line, water outlet, etc? What causes it to fix itself, continually revving the engine? pumping throttle? idle? or what? There's been a lot of good suggestions I've not read the outcome to, like water on the carb. HAve you hotwired it to eleiminate the wiring harness, ignition switch, etc? Alternator producing a steady output? WHen it happens is there compression?

sgwilson904 01-31-2013 03:04 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

Quote:

Originally Posted by H. L. Chauvin (Post 582219)

Vapor Lock --or vapor in a fuel line
...I suggested that he leave the ignition switch off and while reaching across the engine, engage the starter and allow it to spin for 20 or 30 rounds with one hand while touching the fuel line with another. He called me back and said it didn't even spin 10 rounds before the fuel line got hot enough to burn his hand.

BRENT in 10-uh-C

Follow-up #3 as promised:

I had high hopes for this idea but, alas, when I let it spin 30 times or so while holding the fuel line, I felt no change in the warmth of the line whatsoever. So now...is it still worth cutting the line and splicing in a rubber tube, or add a ground from the frame directly to the engine?

I'm a little wary of hanging gasoline above the engine with a direct feed to the carburetor and taking off down the road at 50 mph though this actually COULD prove to be the ultimate solution to ALL my problems! Ka-BOOOM!

Answering noboD post just above:

Yes, does not shut off entirely, just sputters and pops and backfires so it will not drive.

No temp checks taken when it does this, although I note water temp gauge shows higher readings when stopped at a light after long cruise and just before this misbehavior starts.

The only thing that seems to fix it is to let it sit and cool. Then, it seems to work fine for a while again. Have yet to try pouring water on carb to see if that might alleviate some kind of vapor lock there...will try that at next opportunity.

Also, have not hotwired but amp meter indicates steady output from the alternator and there does SEEM to be steady compression as well.

Tom Wesenberg 01-31-2013 03:32 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

I would run the tank almost empty and fill up with good gas with no ethanol crap in it. That would be an easy check to eliminate one possibility.

700rpm 01-31-2013 04:12 PM

Re: Who Can Diagnose THIS Total Mystery? Win A Prize?
 

I have never experienced the fabled (mythical?) vapor lock, but I remember in an earlier thread two suggestions that people who have experienced it said worked for them: 1) clip one or two wooden clothespins to the gas line. I guess these would act as heat sinks if the line is getting hot. 2) Add a pint of Marvel Mystery Oil to a full tank of gas and watch for the symptoms.

But I still suspect electrical.


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