Stalls Immediately After Starting

[Mikey93]

Can Anyone Help Please?

96 Prado 1KZ-TE will only stay start if key is held at 'START' Position. When key returns to 'ON' Position engine dies immediately.
New Fuel filter has been installed, timing checked and continuity at ignition switch checked.
Dash Lights illuminated when Key is at 'ON' Position as well.

 

[fildigger]

Surely the ignition switch is at fault here?

 

[Shayne]

I don't like electrics but i'm thinking the engine runs when power is coming from the battery , when you go back to the on position the batteries power is replaced by the alternator ?

 

[Beau]

Sounds like the ignition switch is faulty... I had a similar problem with a VW. Did this starting issue just occur one day or was it a gradual thing?

When holding it on start, isn't it still spinning the starter motor?

 

[Mikey93]

Surely the ignition switch is at fault here?

Have checked the ignition switch and it seems to be in working order.
Also have dash lights on when ignition is on.
But thanks for replying

 

[Mikey93]

Just happened one day and now will not start.
Having the starter motor running is probably the only reason it still keeps the engine running when at 'START' Position.
Thanks for replying.

 

[Mikey93]

I don't like electrics but i'm thinking the engine runs when power is coming from the battery , when you go back to the on position the batteries power is replaced by the alternator ?

Think all power comes directly from the battery, the alternator just charges it rather than replacing it when at 'ON' position.
Thanks for replying

 

[Shayne]

Yes sorry it came from a vague recollection of having to start a digger and a dump truck every morning for a week when they only had one battery between them many years ago . Your battery is probably dead now it doesn't take many false starts to kill it . Thinking about it it must be the switch because you have an electric fuel pump so it wouldn't fire at all if the fault was anywhere else .

 

[StarCruiser]

Hi Mikey, have you tried running it from a can so the fuel is going direct into the pump with a piece of new hose? Also, check for voltage on your cut off solenoid.

Shayne, diggers and especially dumpers, usually are totally mechanical and require a lever to be pulled to stop them, not relying on voltage being present to hold a valve open, hence why you could swap the battery. Some road compressors used a clockwork starter that you wound up with a handle before flicking a lever to stop the herberts nicking the batteries. Worked very well. Sorry, OT.

 

[Beau]

When you say it starts, does it run smoothly or it it lumpy and unsettled? Bad glow plugs/ no power to the plugs can make for a poor start. Check for the power at the glow plug bar. It's a black bar that runs over all for glow plugs.

Your problem does sound rather electric and unfortunately I haven't really heard of a problem like this before, for Toyota's that is. On other Vehicles, it's usually the ignition switch...

In general for a good diesel to start and run you don't need much... Good compression, heat from glow plugs, air and fuel. Being that it actually fires you're getting fuel and most likely compression. Then either something electronic is knocking off the pump and stopping fuel entering the engine, or the compression or glow plugs are very poor that the engines momentum isn't enough to keep the engine turning over. I''d start with the electric system as it's the most possible idea considering the problem started randomly. Have a search online and find the 1KZT-E Engine manual. You can then find the fuel pump section and test the connections for power, as well as there resistance.

I don't think it can be a immobilizer because it usually gives you a couple seconds before switching back off on these trucks, right? Here's a wild kinda idea for you to rule out the ignition. Whilst cranking the engine over in start position, have someone disconnect the positive lead running to the starter motor so the starter stops spinning, but leave the key on the "start" position and see what happens? I'll let someone comment on this, as I'm not sure if it's safe. It kinda just popped up in my head

 

[Shayne]

You could unplug the starter going in through the wheel arch Beau its on a plastic connector same as those on your pump , i don't think it would do any harm but i don't think it bring us any closer to finding the actual problem either . Continuity at the ignition switch has been tested and passed which got me thinking how could a broken switch test ok . A bad earth connection maybe ?

 

[Trevor]

I had similar but was caused by low oil pressure. I ended up changing both the filter and oil pressure sender and that fixed it for me.

 

[Trevor]

Another 90 I had with similar troubles was cured by unplugging the connector into the ECU behind and above the glovebox removing and reseating those connections cleaned up some oxidation in the connection.

 

[StarCruiser]

Another 90 I had with similar troubles was cured by unplugging the connector into the ECU behind and above the glovebox removing and reseating those connections cleaned up some oxidation in the connection.

That sounds worthy of a visit Trevor if you ask me.

 

[StarCruiser]

Without knowing this engine and seeing mention of an ECU, is there any diagnostic that can be applied?

Check fuses, relays, any and all plug connections. Gotta start with the numpty stuff.

 

[Beau]

You can jump two pins on the diagnostics port to pull any codes, but if the check engine light hasn't been on at all, then no codes will be logged.

 

[StarCruiser]

I had total failure of everything on my Smart soon after a new ECU was fitted. Turned out to be a dirty/ burned pin (or so Mercedes say) that fed power to the ECU.

Check for loose connections, burned contacts or pins in plugs, fuse holders, relay bases that sort of thing. And of course the ECU.

 

[Mikey93]

I Have disconnected the starter when started on 'START' Position and engine dies.
So now it is a case of 'Does Not Start'.
Have also tried diagnosis machine but it will not link to the vehicle even though all the engine details are recognised.
Also tried to short out Terminals TE1 & E1 on the diagnosis Port on engine but doesn't seem to be doing anything different.
All fuses and relays have been tested and are good.

Will check the ECU and surrounding area for any signs of fault/defects and give the components a good clean.
will let you all know how it goes.

Thanks a lot Guys

 

[StarCruiser]

Look for any signs of water damage under the dash too Mikey. Especially around the ECU if that's where it is. Sounds like something's missing its power somewhere or an immobiliser or such like is holding it off. Test for voltage at the fuel valve on the back of the pump. If it's a common rail type, they can have multiple valves.

Sorry, just generic troubleshooting from me I'm afraid.

 

[Shayne]

Graphite powder into the key barrel might possibly reveal the key is not engaging the switch .