Glow plug system

[T J]

Hi
I have a 1993 Mitsubishi MT15 D diesel tractor, 3 cylinder I recently bought. Used of course. I turn the key on, the glow plug light comes on, I let it be for a minute, then try to start. I was told to just turn the key on (there is not another glow plug "switch" nor do you turn the switch the opposite direstion to heat glow plugs) and wait a minute. It takes several cranks before it starts. I tested the glow plugs. The glow plugs are good. I don't know if the relays are good. and don't know how to test.
I have a Mitsubishi D2350 and it starts right up after using glow plug part of switch.
I also have a Bolens diesel and it has a seperate glow plug "switch" you turn and hold for 30 seconds or so to heat the glow plugs.
Suggestions welcome.

 

[ericm979]

Many newer tractors have a glow plug timer that comes on automatically when you switch the ignition on. The timer may measure engine or ambient temp to determine time, or it ma be a fixed time. They usually have an indicator on the dash which lights when the plugs are on and turns out when they go off. It sounds like yours does not have the indicator. You might look for an owners manual to find out.

A minute is probably too long to wait though, and may be why it's hard to start. Try 20 seconds.

 

[T J]

Thank you. This is a 1993, so I don't know if this is considered newer? I tried about 30 seconds and about one minute. Seller told me wait about a minute. but I don't think he know for sure either. I'll try your suggestion.

 

[LouNY]

Do the glow plugs get hot to the touch ( be careful could burn),
or check for voltage to the glow plugs with the key on.

 

[T J]

Yes they checked out okay. What should the voltage be to the glow plugs. I aSSUME YOU WOULD JUST PUT THE POSITIVE LEAD ON THE GLOW PLUG STRIP AND OTHER LEAS ON GROUND TO MEASURE?

 

[LouNY]

Yes that is a quick easy way, most you will get 6-8 volts to ground.

 

[Hay Dude]

Yes they checked out okay. What should the voltage be to the glow plugs. I aSSUME YOU WOULD JUST PUT THE POSITIVE LEAD ON THE GLOW PLUG STRIP AND OTHER LEAS ON GROUND TO MEASURE?

When you say they checked out good, do you mean they get power, or are they actually getting hot?
They could be getting current, but the element itself not working. A 1993 is a pretty old tractor and could need new GPs

 

[T J]

I tested the glow plugs individually and all were okay.

 

[DonRybak]

TJ, when you say they tested good individually do you mean you removed the wire from each and measured the resistance of each one or that they each are getting hot?

 

[LittleBill21]

put an amp meter on them. should pull over 10+ amps, easiest way to confirm