Ford Model A Pickup Restoration October 2017

During October I wanted to fix my little problem, namely the misfiring and total loss of power. However, I took me more time than expected to find the root cause …

Ford Model A Restoration Project October 2017

In the past, I had some sporadic power loss with misfiring. It felt like you turn off the ignition key. When it happened, the engine was a little bit hotter than normal but not boiling. I normally stopped the car in such a situation, opened th hood and let it run in idle for 3 Minutes and could continue the journey and it did not occur anymore for that day. Now follow my long odyssey until I could find the bug …

Ford Model A Restoration Project October 2017

Due to the 'ignition dropouts', I first changed the condenser. It was already broken some time ago, but in that case it was no longer possible for me to drive on a slight slope. The first run I have planned on a Sunday, but after a 1 km, the first dropouts and misfiring forced me to stop the car. After a while I continued to drive the car but after short time the next bang … Now I had a situation where I could not make any bigger journeys with the Ford, but the advantage was that I have now a test track, where the problem occurred very quickly. At this point I didn't know that I had to make another 9 runs to find the problem.

Ford Model A Restoration Project October 2017

Next, I changed the ignition coil - which of course had + and - swapped compared to the old one, but luckily I noticed that before I mounted it. Test drive … problem same as before.

Ford Model A Restoration Project October 2017

Now I have gradually swapped everything that you can exchange such as plugs, ignition cable, distributor body, distributor rotor, etc. … My thought was, among other things, inside the distributor body the spark breaks trough and therefore a cylinder would get the spark at the wrong time. Unfortunately, this exchange did not make it better.

Ford Model A Restoration Project October 2017

I still had a complete distributor base that I wanted to swap as a whole. Easier said than done. The replacement part did not fit on the cylinder head. The bolt which protects it from twisting should fit into a hole in the cylinder head - only a file helped to make it fit. When I turned the shaft of the distributor a little bit, I saw that the plastic part of the breaker arm moves outwards, but the breaker arm itself still was closed. I saw that the breaker arm was badly riveted with some gap between the two parts. The part immediately flew into the bin and I replaced it with a better version.

Ford Model A Restoration Project October 2017

When removing the old distributor (left in the picture) I noticed that the case was also painted below. I have sanded this paint for (much) better ground contact.

Ford Model A Restoration Project October 2017

The second problem with the old distributor was the point where the cable of the condenser is attached to the circuit breaker. The cable lug of the condenser can come into contact with ground and the condenser has a short circuit. I have bent the shoe slightly to fix this potential problem.

Ford Model A Restoration Project October 2017

Now the new distributor body is installed and the breaker gap I have already set. Never do this with an oily feeler gauge - clean it before using. Then I did set the ignition timing and I could do another test drive. Unfortunately it did not work because the engine did not start at all. The troubleshooting then showed that the breaker in the closed position had no connection - not 0 ohms but infinite ??? !!! I was quite surprised, but it must have had an oxide layer on the contacts, which I removed with fine abrasive paper and finally the motor gave a sign of life. Test drive made - no improvements :-(

Ford Model A Restoration Project October 2017

Next I wanted to control the wiring for broken cables or ground connection where no connection should be. First, I removed the instrument panel and checked if everything is ok. At the A-meter I found a loosened nut which I solved with an additional spring washer.

Ford Model A Restoration Project October 2017

Afterwards the terminal box was examined more closely and at one pole the nut was not tightened as it should be … could that be the problem? At the same time I wanted to exclude the ignition switch as a source of error and bridged it by passing the cable from the ignition distributor directly to the + pole of the ignition coil. There is a special cable to buy with screw for the ignition coil side and a clamp on the other side to connect the coil. To stop the engine you have to stall the engine and then not forget to disconnect the battery or the clam on the coil. Test drive? Negative!

Ford Model A Restoration Project October 2017

Well there is still the A-meter and the cables to and from there which I will bridge next. Simply connect the yellow and yellow/black cable from the starter (battery) and generator to one pole of the terminal box (disconnect all other cables there) and connect the negative pole of the ignition coil (black cable) with the 2 cables too. Unfortunately, this still did not bring the expected improvement but I was able to exclude all cables which lead to the instrument panel including the ignition switch and A-meter as sources of error.

Ford Model A Restoration Project October 2017

I then disassembled the carburetor, cleaned it and also drained some gas from the gasoline filter but found nothing suspicious. I did that at the time because I wanted to exclude everything - but did not know yet that I was pretty close to the problem.

Ford Model A Restoration Project October 2017

In the meantime, I ordered a few spare parts like breakers, condensers, cables, … just to be prepared should all my actual replacement parts be defective ;-)

Ford Model A Restoration Project October 2017

Now I wanted to be 100% sure about the ignition during my dropouts. So I attached my GoPro with suction cup under the hood with a view to the top of the open distributor and made a test drive. Unfortunately, the camera freezed before the interesting scene was captured (GoPro apparently does not tolerate much heat…). With the next try, my camera did also freeze and after camera restart, the message 'Repairing File …' was shown on the screen, but I was lucky and the interesting scene was clearly visible. When the dropouts / misfiring happened, the spark was always available! The good news are that it's not an ignition problem, the bad ones, what else could it be? Why did I not use the camera earlier??!!

Ford Model A Restoration Project October 2017

What I could not really imagine was a problem with the valves. A hanging valve was not very plausible and I adjusted the valve clearance some months ago. Nevertheless, I dismantled everything and measured the gap again. Result, camshaft and valves are fine.

Ford Model A Restoration Project October 2017

Well, what remains which I have not checked yet? There are 3 questions when a motor is not running:

- Does the engine have ignition? Yes, verified with GoPro
- Does it have air? Yes, my carburetor is open - so there's enough air
- Does it have gas ???? Only this point remains!

At the beginning, before a drive, I have drained some gas at the gasoline filter (sediment bulb) and my conclusion was that if gasoline runs out after the filter, the rest of the lines up to the gas tank should not be a problem too. Since I could now exclude the first 2 questions, only the gasoline supply came into question. I then placed (again) an empty bucket under the bulb and opened the drain plug. Make this only with a cold exhaust, otherwise it can become quite warm … But to my astonishment, not a single drop of gas came out. I was aware that at the time I did not have much fuel in the tank, it was filled with less than 1/4, but about 15 liters should be enough to supply the carburetor with fuel. To see what's going on with the pipe, I've mounted a short hose at the outlet of the bulb to blow in and see what happens. I had to build up a fairly high pressure until it bubbled in the tank and from this point on, the gasoline flowed again.

The problem seems to be found - but now I have to clean everything starting with the bulb and up to the gas tank.

Ford Model A Restoration Project October 2017

When disassembling the sediment bulb, everywhere were tiny plastic plates which have clogged the line.

Ford Model A Restoration Project October 2017

After draining the remaining fuel, I cleaned all pipes and the gas valve. It turned out that small splinters have detached from my inner coating of the tank (made with 'Tank Cure') and then disrupted the supply of gas. I did the coating with Tank Cure in 2006 and since 2015 there is gasoline in the tank. With such problems, I cannot recommend this product anymore :-( I have to take some more shots from the inside to see how bad it looks like … Since I believed in this product, I did really not expect such a problem!

Ford Model A Restoration Project October 2017

Here is a picture of my motorcycle tank I have treated 2011 with POR 15. Although the motorcycle has only been standing in the corner since then (with old gasoline), the inside of the tank looks perfect. From today's perspective, I would definitely treat the tank of my Model A with POR 15 too.

Ford Model A Restoration Project October 2017

Of course, I did not expect such a simple problem, but when I think about it, everything fits together:

- The car was standing, so the carburetor could fill slowly despite clogged line, but then run empty after a short drive with the known dropouts / misfiring.
- Misfiring in the exhaust occurs only when the mixture is too lean or when the exhaust can suck wrong air. In that case, the carburetor was too lean due to missing gas.
- I had the feeling that the engine was hotter than usual when I had the problem - this fits too and is due to the lean mixture.
- Could it have been found earlier? - Yes, if I had not been convinced of 'Tank Cure' and therefore did not consider this source of error …

Ford Model A Restoration Project October 2017

Now I have a filter mounted in the gas tank, so that such plastic parts do no longer bother me in the future. The filter is directly mounted on top of the gas valve. Irony of the story, I wanted to mount this filter from the beginning, but I have not found it when installing the valve and subsequent mounting means draining gasoline and is associated with a bigger effort.

Ford Model A Restoration Project October 2017

The month of October was turbulent but I have learned a lot. I guess that I'll find future problems faster :-) In any case, I found the problem - yes, the last test drive was now successful and as a side effect, I have found other potential sources of problems and fixed them:

- Spare distributor not mountable - would not be any help during a drive
- 1 breaker is scrap - proper ignition timing is not adjustable
- 2 loosened cable lugs - would probably have led to problems later


My last run for this year is made and I also have the oil changed. Over the winter, I will make a few more optimizations.


And here are my videos and also the one regarding the described misfiring: Ford Model A Videos




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