Foton 254 starting problem

[Bob Rooks]

Obviously your "dealer" used the wrong relay or was improperly installed, but his wiring was correct. Properly done, this fixes most electrical starting issues.

I work with relays (which are actually remote operated switches), and breakers up to 4.16 kV on a daily basis, so what do you mean by "carbon build-up"?

The "tumbler" part of the key switch has nothing to do with the contacts within it. Which are you referring to?

It sounds like bad grounds may have been your problem all along. That would account for the relay going bad.

 

[Rich Waugh]

I don't know what "key tumblers" are. The key switches on these tractors are simple 4- or 5-pin barrel cylinders with no tumblers. The contacts are metallic, as are the ones in relays, so I don't know where carbon could be coming from. The relay in the starting circuit is appropriate to keep the key switch from carrying the high load of the starter solenoid coil. If you use a good quality relay, it should last a few million cycles. A high quality, hermetically sealed relay should operate ten million cycles easily. If a relay fails early it is usually due to using an under-sized relay for the load or from having bad wiring on the load side so the contacts see high resistance and arc.

 

[succor]

OH.. I stand corrected!

 

[greg_g]

There are literally thousands of different relays, there's always a chance that the wrong type was selected. And they're not all hermetically sealed. A very common and appropriate type used for automotive/agricultural starter motors is the inexpensive Ford type.

It doesn't like water. Power washing will take them out, as will snow/ice if they're mounted in an exposed position. If enough moisture is permitted to accumulate on the end where the wires connect, it can cause an arc between posts. It only takes once, and then it's new relay time.

//greg//

 

[succor]

Thanks Greg, I appreciate that information as I believe that probably happened to the relays I had. Diesel and water had been exposed to the relays a few times problably doing something to them like you said. Now that being said I problably will try a relay inline with the iginition again but wired better so I don't hurt the key switch and less chance of wiring problems in the future.

 

[greg_g]

Ok. If you find you'd like assistance getting a replacement wired in correctly, give me a shout. There's always a chance that it was installed incorrectly in the first place.

//greg//

 

[Bob Rooks]

This is the sealed version of the same relay.

 

[succor]

Hey everyone, I fixed alot of wiring on this unit and got everything electrically working and starting good with a new relay in the cct. Now a new problem; when I start the tractor, it idles really low and rough and it's hard to rev it up but it won't stall. During the electrical work I was doing, I had lifted the fuel tank away and set it aside with the bowl still attached but the injector line on the side disconnected for a couple of days. Also very little fuel left in the tank so I could lean the tank on it's side to move it out of the way. I'm wondering if there is air in the line or a lock of some sort. One other thing I did is with the injector line disconnected from the fuel tank, I would turn the engine over for a split second a couple of times to see if the starting was working before I put the tank back in. There was a couple of spurts of fule from that injector line that went on the floor. Any ideas or tricks here?

Thanks

 

[Bob Rooks]

Do you have oil in the fuel injection pump/governor assembly? Since you removed the tank and set it on it's side theres a good chance you stirred up some gunk that was on the bottom and it is restricting flow due to a plugged sediment bowl strainer. Otherwise it sounds like the fuel system just needs to be bled real good.

 

[greg_g]

With the fuel tank removed and an open hose on the low pressure side, gravity may have drained fuel from the high pressure side on at least one cylinder. So it's possible you're running on fewer than all three cylinders. Follow the steel fuel lines to the top, and locate the individual hex collars that fasten the lines to the individual fuel injectors. Get the appropriate sized open end wrench, preferably a line wrench.

Tractor in neutral, brakes set, start the engine. Loosen the first hex collar, observe for bubbles or fuel. If bubbles, wait. When raw fuel comes out, tighten the collar. Repeat for the other lines as necessary.

//greg//