How to start a Toyota diesel engine?

[bikemaniac]

Hi,

I have been looking in my L and 2L user manual. It states that when you are starting a cold engine, you need to fully press the accelerator pedal to the floor while you ignite/start the engine. As soon as the engine runs, remove the foot from the accelerator pedal and let it idle.
I always started a diesel engine WITHOUT touching the accelerator pedal at all.
Can somebody explain why Toyota suggests to do it like that?

The above leads to my next engine starting question which I experience with a warm Toyota engine, both L and 1HZ. If I dont touch the accelerator pedal while starting, it is like if the engine starts almost too fast! It feels like the starter motor only has to make half a turn before the engine starts and it feels like the "stumbles" upon itself ... it feels like the starting procedure confuses the engine during the first few revolutions before the slow perfect idle kicks in. With a gasoline engine each start up procedure feels "normal" with no "confusion". Can anyone comment on that?

Thanks,

Lucas

 

[lostmarbles]

Hi there Lucas.

I'll comment on the first bit.

I've never understood why Toyota like to advise "depressed accelerator" when starting our diesels. My Owners Manual for my 1979 BJ40 says the same thing and as far as I'm concerned it's completely unnecessary.

The EDIC system on my BJ40 ensures overfueling during cranking which in my opinion is entirely sufficient without the need for me to touch the accelerator. (So I only touch the accelerator once it's started to gain and maintain a smooth idle, keeping it high to begin with, and lifting my foot to reduce the idle rpm as I feel the engine warm up and maintain a regular beat.)

Not everything Toyota puts into print is correct .... But why they've repeated this "bad advice" in multiple owners manuals is beyond my understanding..




PS. Just had an idea.. Perhaps Toyota would have liked to have advised the starting procedure I've written above... But some marketing guru probably advised against it on the basis that prospective purchasers might consider these engines too temperamental (and that therefore these people may take their money elsewhere and buy a different brand)?

 

[MatS]

Possibly due to emission, if your EDIC is overfuelling for startup than it would only make sense to open the throttle to allow the most air in to and produce the least amount of smoke/unburnt fuel?

Just a thought, no really opinion on the topic as when I start my 2L I use the accelerator pedal to set my idle speed up and manually adjust my high idle cable to hold it there.

 

[jzilla]

Could it be so that the venturi butterfly valve is fully open, therefore not restricting air into the intake manifold?
Not sure about those engines, but that is my thinking for the 3B...

 

[lostmarbles]

Possibly due to emission, if your EDIC is overfuelling for startup than it would only make sense to open the throttle to allow the most air in to and produce the least amount of smoke/unburnt fuel?
Just a thought, no really opinion on the topic as when I start my 2L I use the accelerator pedal to set my idle speed up and manually adjust my high idle cable to hold it there.

Could it be so that the venturi butterfly valve is fully open, therefore not restricting air into the intake manifold?
Not sure about those engines, but that is my thinking for the 3B...

That they advise "foot on accelerator" in order to have the intake butterfly open appears to make sense.

Except in practice I finds mine starts best/easiest without my foot on it (and thus with my intake butterfly only marginally open). (I've always understood that diesels aren't temperamental about how much air they get in terms of "igniting the fuel" and this appears to be evidence of that. But then again, we must remember that while cranking the air-flow requirement is minimal anyway ... even less than when idling ... because cranking at best is 250rpm and idling is 650rpm.) .... (These figures are for my B-engine of course..)

But I like your connection with emissions/environment MatS.. That sounds plausible (although working against it is the fact that Toyota started giving this advice back in the 70s when environmental concerns weren't much of an issue in the minds of members of the general public).

 

[jzilla]

In practice I also have never used the foot on the accelerator technique...
The only time I had a hard time starting my 3B was when I forgot that I had put duct tape on the turbo intake to keep dust out when doing some other work...I guess the engine was getting zero air

 

[lostmarbles]

In practice I also have never used the foot on the accelerator technique...
The only time I had a hard time starting my 3B was when I forgot that I had put duct tape on the turbo intake to keep dust out when doing some other work...I guess the engine was getting zero air

Yeah... I guess that proves they do need at least some air...

Thinking about this more.... The biggest drawback with trying to start my diesel while the accelerator is depressed is the fact that this would make it roar up to full revvs before the oil has even begun to circulate. And that's just stupid!

 

[MatS]

What about getting the engine to rev up a bit higher on startup to even out the combustion and get it running smoother faster? I'm just tossing out crazy idea here haha. If I fire up the 2L without any throttle input it shakes like a bastard for a bit until they're all firing at the same temperature but the smoke is fairly minimal. If I give it 1/4 throttle on startup and set my high idle to 800-1000 rpm it's much less violent on startup and being that they switched to the smaller diameter filter on L engines at least means the oil is getting to the top of the engine faster.

I still do not recommend full throttle start ups... that just seems silly on multiple levels. Who knows... maybe it got mis-translated when it got changed to english?

 

[lostmarbles]

What about getting the engine to rev up a bit higher on startup to even out the combustion and get it running smoother faster? I'm just tossing out crazy idea here haha. If I fire up the 2L without any throttle input it shakes like a bastard for a bit until they're all firing at the same temperature but the smoke is fairly minimal. If I give it 1/4 throttle on startup and set my high idle to 800-1000 rpm it's much less violent on startup and being that they switched to the smaller diameter filter on L engines at least means the oil is getting to the top of the engine faster.
I still do not recommend full throttle start ups... that just seems silly on multiple levels. Who knows... maybe it got mis-translated when it got changed to english?

Yeah. I'm not against partial use of the accelerator either.

It's the silly "pedal-to-the-metal" advice that gets me..

Here's were it all started.... (An exerpt from page 45 of the 1974 Owners Manual):

PS. Hey... "Just read the bit "if the engine starts firing, keep the starter motor running until the engine revolution becomes smooth". At least they dropped those words in later Owners Manuals because I can see this statement encouraging some owners to keep the starter motor going when the engine revvs (due to those cylinders that are firing) are too high.

I think they meant to say "if it starts to fire on just one or two cylinders and still hasn't "caught" properly, try to keep her cranking until she's firing on a few more. And if she doesn't fire on a few more (and thus doesn't pick up rpm), revert back to applying preheat.

But of course I'm too verbose for what I've said to be used in an Owners Manual...

 

[B Point]

.....tap the key on a 1HD-T....stupid fast startup..

 

[northernrighty]

.....tap the key on a 1HD-T....stupid fast startup..

love that 24v starter, it freaks people out when I show them how fast the 80 fires up, even in winter -30C.

 

[lostmarbles]

.....tap the key on a 1HD-T....stupid fast startup..

love that 24v starter, it freaks people out when I show them how fast the 80 fires up, even in winter -30C.

Here's some info Toyota published on that system back in 1990. It is a far cry from the simplicity found in a 40-series but sounds like it works a treat:

 

[Tapage]

all weird .. I never touch the skinny pedal not in my old 2H neither in my also old 1HD-T .. the HD-T starts withing turn of the starter ( our cold which it's not that cold at all ) and 2H maybe take 2 turns of the starter as much ,..

 

[B Point]

As cool as the 12/24v starter system is.... I'd rather have it all 12v actually. I keep talking about it and one of these years I'll should just do it.