naa runs rough

[LLIHKAO]

I have a 1953 Ford Jubilee and Im having a lot of trouble with the distributor system. The tractor suddenly stopped running and I then replaced the coil, rotor, points, and condenser. Still wouldnt start. I used an emery board to sand the points down so they would make good contact and then the tractor started. It was running a little rough so I loosened the bolts holding the distributor in place and tried to adjust the roughness out. I found a distributor position where the tractor ran great. It would run great for about 5 minutes then it began running so rough it almost died several times. It would then run great for about 5 minutes then start running very rough again. I pulled the choke to see if it was starving for gas, no change when I pulled the choke. I tried rotating the distributor again without any success. It did seem when the tractor was running great, I would tighten the 2 bolts holding the distributor in place and the tractor would begin running rough again. Sometimes I could loosen the bolts and the tractor would smooth out a bit. Any ideas? What can I do? Thanks a lot.

 

[Bruce (VA)]

Did you miss my reply on the other board?

In case you did, here it is again.

" Any ideas? What can I do? "

There are 2 answers to that question. The short answer is your distributor isn't grounding.

The longer answer is learn how to troubleshoot a problem before you start buying parts.

What you have done is replace good working parts in an attempt to fix an undiagnosed problem. I?ve done that and I?m sure others around here have done it too.

You have spent probably $50 plus hours of time & frustration w/o having the slightest clue as to what is causing the tractor run rough. Worse yet, by replacing all of those parts, you have probably introduced more problems. For example, you have cut the life expectancy of a new set of points by sanding them. Dressing points with card stock or brown paper would have been a better alternative.

The one way that I found the best results with is to take a systematic, step-by-step approach to solving the problem, working from most likely to least likely. The trick to fixing these tractors (or trouble shooting any piece of equipment) is to be systematic about it. You need to isolate the problem step by step and work from most likely to least likely. Jumping ahead to 'so-and-so said it could be whatever' or just replacing parts usually just wastes your time and your money. I know it did for me. Remember, it takes three things for an engine to run: spark at the right time, compression, & fuel in the right mixture. For the moment, forget about compression & concentrate on narrowing the problem to fuel or spark. If you don?t do that, you are going to end up chasing your tail around that tractor & spending a boatload of money to fix what could easily be a loose wire or faulty ignition switch. I offer this advice from personal experience because I am not a mechanic. I do not have the ability learned after 30 years of working on an N tractor to simply diagnose the problem & go right to the fix. So, whenever my tractors stop, it's 'check spark, check fuel' and then go from there.

Don?t guess at the cause of the problem; guessing can get expensive. And leave you breathless chasing every guess.......it could be this, it could be that......just troubleshoot the problem and leave the guess work for buying Lottery tickets.

As soon as the tractor stops running, not 5 minutes later, check for spark and fuel.

You need to answer 2 questions before you do anything else:

With the bolt in the carb bowl removed and the gas on, will the fuel flow fill a pint jar in less than 2 minutes?

Next, get out your adjustable gap spark checker * , open the gap to 1/4", hook it up, turn the key on and crank the engine. Does the spark jump 1/4"? Post back with the answers.

As I also mentioned, old MG's had a ground strap from the distributor to the frame. If your plate is dirty/oily, the points aren't grounding. Same with the case.

Just put a meter on it & check it out.

And do not buy a new part for the tractor until you can answer this question: how do I know the part on the tractor is defective?



* Don't own an adjustable gap spark checker? Buy one! Not a test light! Until then, take an old plug, open the gap 1/4" ground it to the head & look for spark. It?s not the color of the spark that counts; it?s the distance it jumps.
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[LLIHKAO]

yes i did reply. how should the distributor be grounded?

 

[Bruce (VA)]

As I also mentioned, old MG's had a ground strap from the distributor to the frame. If your plate is dirty/oily, the points aren't grounding. Same with the case.
Just put a meter on it & check it out.
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