Starting Up a Diesel

[JoeyBigBlind]

My shortie is the first diesel I've owned. I know you're supposed to wait for the glow plugs to cycle before starting. But if it doesn't start on the initial crank, and you turn the key off and back on, do you need to let the glow plugs cycle again? Or can you just start cranking since they cycled the first time?

[Brad_SwiftFur]

I'm going to assume you are referring to an '86 6.9 L diesel, since that's what your profile shows. Those Fords usually had a "wait to start" light which indicated the glow plugs were heating up. If you turn on the switch and see that light, wait until it goes out before turning over the starter.

Some may not have this light, so I'd give it a couple seconds each time you are starting it.

Not all diesels have glow plugs, that I am aware of.

[JoeyBigBlind]

Yes, it's the Ford E350 6.9L diesel. There are a set of red lights on the dash and I can hear a series of 5-6 loud clicks when they cycle off and on. After it stops 'clicking', I crank it, but it may take several attempts to crank it before it will start. Each time I turn the key off and back on, I can see/hear it cycle. My question is - do I need to let it cycle after each turn of the key - even though it has already cycled once before? Or if they have cycled once on the first start attempt, can I just continue cranking?

Also - would bad glow plugs be a reason for the hard starts?

And I never knew that not all diesels have glow plugs!

Thanks!

[Booyah45828]

Your diesel should fire up on the first try, unless its cold outside.

You'll have to do some diagnosing on it. The glow plug control module could be bad(mine is) you could have bad glow plugs, or you could have a bad solenoid.

Use a multimeter and see if you have power to them. Even if you had a few bad plugs it should still sputter to life with a miss until all cylinders come online. My guess is that your control module or the solenoid is bad.

Another hint is to push the throttle pedal down an inch or so when trying to start it. Once it does fire you let off so it returns back to idle. Doing that seems to help start mine quicker.

[JoeyBigBlind]

Thanks! It was sitting for a good year before I bought it, but still had it's regular maintenance. I did use starting fluid to start it the first few times, but now it starts with out it, but does take 2-3 crankings.

[Tango]

Not at all that familiar with that particular engine, but if it uses a "lift pump" to prime the main pump...you might check it. Sounds similar to what happens when a Cummins lift pump starts to go south. Just not getting adequate fuel in a single cycle but after a few...it will light off.

[cowlitzcoach]

Unless your engine is really tired or if it is really, really cold outside your engine should start right up after the first cycling of the glow plugs.

If the ambient temp is above 40* and your engine once it starts doesn't smoke and use oil I would suggest you have two or more glow plugs that are dead.

In my experience most glow plugs are good for about 50K miles, depending upon how many times they are cycled. My experience was with buses that would be started multiple times per day.

With 8 glow plugs working they started right up.

With 7 glow plugs working they still started right up.

With 6 glow plugs working it might take two cycles to start right up.

With 5 glow plugs working it took a minimum of two cycles to start right up.

With 4 glow plugs working it was rather difficult to start up.

With less than 4 glow plugs working they would not start without help.

One way in which to test the starting ability is to plug in the block heater. If your bus starts right up when the engine is warm your issue is with the glow plugs.

Since you can hear the controller cycling you know that part of the system is working correctly.

On my 1994 E-350 there was one glow plug I never did replace. It was buried under coach builder's A/C equipment. The amount of time ($$$) it would take to move all of it out of the way wasn't worth the effort in my book since the bus started with 7 good glow plugs without any problem.

[Booyah45828]

Originally Posted by Tango

Not at all that familiar with that particular engine, but if it uses a "lift pump" to prime the main pump...you might check it. Sounds similar to what happens when a Cummins lift pump starts to go south. Just not getting adequate fuel in a single cycle but after a few...it will light off.

It uses a mechanical lift pump. But they aren't historically known to go bad like on a cummins. The glow plug system is pretty easy to check with a multimeter. So after they go through that and it still has the problem we can check the fuel system.

[EastCoastCB]

Not a Cummins, but here's a FL cold start on my bus.

https://www.youtube.com/watch?v=0nrb1u_8TS8

[cadillackid]

Originally Posted by EastCoastCB

Not a Cummins, but here's a FL cold start on my bus.

what was that yellow light above your brake pressure alarm light? your dash looks like mine but ive never seen that light before..

-Christopher

[JoeyBigBlind]

WOW! Just turn the key!!!

[EastCoastCB]

Originally Posted by cadillackid

what was that yellow light above your brake pressure alarm light? your dash looks like mine but ive never seen that light before..

-Christopher

Its not yellow, half the red film is slid down making it look that way. Its just the air pressure warning light. Goes away after it gets to pressure.

[EastCoastCB]

Originally Posted by JoeyBigBlind

WOW! Just turn the key!!!

YEp, even in Kentucky in 10*, with icicles hanging in/on it.

[cadillackid]

im assuming your DT is like mine where these no glow plugs or grid heater?

I love the fact its not like the old scout where I had to hold the glowplug button for 3 minutes in -10 degree weather

-Christopher

[EastCoastCB]

Originally Posted by cadillackid

im assuming your DT is like mine where these no glow plugs or grid heater?

I love the fact its not like the old scout where I had to hold the glowplug button for 3 minutes in -10 degree weather

-Christopher

No glows on a DT.