land cruiser 1hz engine will not start when warm/hot. (1 Viewer)

[Alec Vincent]

Hi everyone.

This is my first post on the forum and I am seeking some help.
I have acquired a 45 series cruiser which has had a 1hz put in it. The car has been off the road and I am slowly getting it restored.
I have now managed to get the engine to start fairly easily when cold with about 10 seconds of heaters it fires up. However once the engine is warm/hot it will not start at all even if you try with or without plugs.
I have checked everything which I can think of.
The starter has just been refurbished and the battery voltage goes down to about 10.6 ish when cracking which I thought was Ok?
There is 12 volts going to the IP soliniod and I can hear it click.
I have installed a new battery
I have installed an online filter just before the IP so I know the fuel is getting there. And I have also cracked open an injector which also has fuel.

I am a petrol mechanic so not too clued up on these engines. Any help would be much appreciated as I am pretty much out of ideas.

 

[Alec Vincent]

Sorry I forgot to add, even though it will not start from the key when hot it will fired straight up if you give it a hill/bump start. Thanks again .

 

[MrMoMo]

This would likely get more responses in the diesel section, but I'll ask a question that may clarify things a little...

You say it won't "start" by that I assume you mean it rolls over but won't fire... If that is the case you pretty much have two options. It's either not getting fuel, or there is not enough compression.

If you mean it won't roll over when hot, but you can bump start it, then it's likely that the wire that runs to yur starter trigger has a connection that opens up when it gets hot, or possibly the starter solenoid has an internal fault that changes with heat...

 

[Alec Vincent]

Sorry I should of been more specific. I mean the engine will turn fine but it just does not fire. I guess checking the compression is my next step, however I am not sure how this would only be affected when hot. And if the compression was low would I not notice this a lot in performance? Thanks.
Also is there anyone who could move this to a better section as I don't want to double post it everywhere.

 

[cult45]

@woody might move it.

 

[Squash]

Seems like the fuel line is sucking air instead of fuel.
Swap out the IP(injector pump) fuel line to primer/fuel filter with a chunk of clear fuel hose. Bubbles indicate air, trace , repair towards tank.
Or just rig up a fuel source to ip via gravity feed if you just want to hear the 1HZ purr.

 

[MrMoMo]

I doubt it's compression, but just putting it out there.

So, you say you have fuel because you cracked an injector line. Did you crack them all or just one?

When it won't start, does it cough, sputter, or just absolutely nothing?

 

[mbashier]

If it starts right up after a hill start, maybe it just needs a bit more oomph with a higher amp battery.

 

[Alec Vincent]

Thanks for all your replies. I will try shaping out the fuel line from the priming pump to the IP today and see what happens.

Mbashier - I have a fairly big battery on it but I will also try jump starting off another vehicle today just to rule that out.

Mrmomo - it pretty much does nothing, it's kind of like if you try to start it when cold without the plugs. You just get nothing.

Thanks again for your help

 

[roscoFJ73]

If it had low compression there would huge amounts of grey smoke on start up and run rough after starting.
Air in the fuel lines usually accumulates overnight and makes it hard to start when cold ,but this is starting ok.

The FSM says it should attain a speed of 110rpm when cold and 150rpm when warm when cranking with the starter motor

When its running, what speed is it idling at? Does it make a difference if you give it some throttle when warm?(normally you wouldn't touch the throttle when starting).
Do the timing marks on the pump line up with the marks on the flange?

 

[Alec Vincent]

I do not think it is a compression issue as the engine runs prefect when started.
I'm not too sure on the turning speeds of the motor as I don't have a working tacho but it sounds like it is turning fast enough to fire.
By flange are you just referring to the time marks? I am planning to check the timing tomorrow.
One thing I did try today is first off went for a small drive and got the car up to 80° (that's what the aftermarket gauge says anyway) I then turned the car off and it started fine. I drive a little further to get it up to around 87-90° (which is as high as it seems to get)and it would not start. I jumped off another battery and it did start but it took heater plugs and a few seconds cranking.
This makes me think it is the starter?! Do you think it's worth taking the starter back and saying I'm not happy with it and ask them to check it over once more?
Thanks.

 

[roscoFJ73]

In regards to the starter, its a bit hard to say . But 1HZs generally burst into life when warm and should only take a second of cranking.
There are some timing marks on the flange and the pump that need to be aligned.
Have you checked the timing belt alignment marks?
Is it making any smoke at all?
Are you using a proper diesel fuel filter?

 

[SeaJay]

it can also be a sign your injection pump needs a rebuild if it starts ok cold, but hard to start when hot

 

[niffa]

I have this exact problem with my hz and still chasing the fix

 

[roscoFJ73]

it can also be a sign your injection pump needs a rebuild if it starts ok cold, but hard to start when hot

I was thinking the same thing ,but a pump would have to be really screwed not to allow it to start at operating temps. Usually the 1st signs are that they lose power at the top end because they can not squeeze enough fuel in when hot. I got that off a guy who rebuilds a up to 50 1HZ pumps a month for the mines.
I was thinking maybe a bad pump with out of whack timing , but all the easy things like fuel supply and filtration need to be eliminated 1st.

Alec , did you see that bit where I asked about giving it some throttle when warm while cranking the engine?

 

[mbashier]

I've always had very limited success with jumper cables. In solving my 1hz starting problems in the first winter, installing a new battery did the trick, but jumping it with the new battery had limited results. But in the broader view, a more powerful battery would probably just cover up another more underlining problem that needs looking in to. Mine was the opposite. Wouldn't start in the cold mornings, but would very easily start the rest of the day when the engine had initially warmed up, which is somewhat normal.

 

[Alec Vincent]

I am hoping to get the chance to check timing marks this afternoon. I will also look for the marks on the flange. (I am guessing they give you slight adjustment without move the timing belt?).
Yes it has a diesel fuel filter fitted to the priming pump. And it is not making any smoke. The engine seems to be fine once started.
regarding giving it some gas when cracking I always find it slightly easier to give it a touch of gas all the time as it seems to help fire it into life. I have been driving the truck around the farm this morning starting and stoping

 

[Alec Vincent]

Afternoon... so I have checked the timing marks and it's all 100%. I have also checked the IP flange marks which was not really lined up with anything so I went for what I thought was correct but unfortunately this did not solve anything.i have been trying to upload a picture of the IP timing marks but 3rd world internet is not on my side today.
Tomorrow i am going to attach a straight fuel feed to the IP just to rule that one out too.

Niffa- will your motor start at all when hot? are you able to bump start?

Cheers!

 

[Alec Vincent]

Please see the file above that i have managed to now attach, it is of what i think the timing mark is on the IP and the flange. Thanks

 

[niffa]

Afternoon... so I have checked the timing marks and it's all 100%. I have also checked the IP flange marks which was not really lined up with anything so I went for what I thought was correct but unfortunately this did not solve anything.i have been trying to upload a picture of the IP timing marks but 3rd world internet is not on my side today.
Tomorrow i am going to attach a straight fuel feed to the IP just to rule that one out too.

Niffa- will your motor start at all when hot? are you able to bump start?

Cheers!

Mine will start with the key but it takes a looong time unless i glow it 3 or four times