Starting a diesel

[BobT]

I used a Ford F250 with a 6.9L for nearly 10 years. I've been using my 190XT Allis diesel tractor for about the same. Funny thing. I have never really given this much thought before now but today it occurred to me that I don't know the answer and I'm hoping someone here can enlighten me a little.

My 6.9L used glow plugs and a throttle solenoid to put the engine at a higher rpm for warm-up. All I ever had to do to start that old truck was turn on the key, press the throttle and release to engage the high idle solenoid, wait for the glow plugs to cycle once, and turn on the engine. Except for extremely cold weather (below -10) it usually started right away. At extreme cold, I would turn the starter for a couple seconds, wait for the glow plugs to cycle a second time, and then start it up.

Anyway, my tractor doesn't use glow plugs but instead has an intake manifold heater. At temperatures below about freezing I just turn the key far enough to engage the heater, wait for 60 seconds, and then try turning over the engine. It usually starts fairly quickly. When it is really cold like today I have to plug the tractor in of course and usually have to repeat the heater/starter cycle a few times to get it to take off.

The thought came to me today and my question is this. When starting in really cold weather like today, should I be giving it more throttle when turning over the engine? According to the manual's cold starting recommendation I give it enough throttle to idle at about 1,000rpm but I'm wondering if it would start better if I gave it more fuel and then back it off once it starts.

Thanks,

[jeffreyd]

you are not really giving it more fuel as in the sense of like a gas engine. the engine (both) use compression to fire off. the ford has glow plugs that super heat the cylinders so when the fuel is dumped in from the injection pump turning it has a warm place to go. the tractor with the intake heater has a glow plug device in the intake manifold. it super heats the air going into the engine and aids with starting. the one thing with both engines is that if you find the need to use starting fluid, make sure you spray it after your have cycled the heating devices. you do not want to ignite the starting fluid and blow up the kit en cabootal. hope this helps

[BobT]

Doesn't setting the throttle to a higher level increase the amount of fuel being injected into the cyclinders and therefore can that help improve the ability of the diesel to ignite or hinder it?

Oh. One thing I never do is use starting fluid to start my diesels. It dries out the cylinders too much for my comfort and as you already mentioned, it is extremely dangerous to use when glow plugs are involved.

[dougger222]

I have always had good luck starting the F250 when I put the pedal down. As a matter of fact on some hard starts I've flored it for several seconds until it fires and then still half on so it won't kill. When it's finally running (when really cold and not plugged in) you can floor it but it won't even rev up because the motors so cold.

The F350 on the other hand seems that it's not good to touch the pedal at all when trying to start it. Again this is when unplugged and cold.

Gonna put another set of Motorcraft plugs in the F250 soon and thinking it may also need to be done on the F350 but will check the relay first.

BTW, both are 99's so over 10 years of use.