Help??

[Kati]

G'day everyone! My dad has 3L 2000 patrol and were really stumped as to what's going on with it, it starts fine and runs good for 15-20 minutes and then starts conking out, he can have his foot flat on the accelerator and it will go but it jerks around and won't go over 20km,pretty much just dies if he takes his foot off but will chug along if he just keeps putting his foot down,he can pull over for 5 minutes and then it will run good again for 10-15 minutes and do the same,we've taken it to 3 mechanics and no one knows what it is,no codes show up and no engine lights come up,we've changed the fuel filter but it sort of seems like no fuel is getting through or something,could it be the injectors or fuel pump even though the engine light doesn't come on? Sorry I'm not very "car savvy" so I hope this makes sense,any suggestions welcomed!

[ricster]

I am also not to ZD30 motor savy, but could it not be the MAF sensor being dirty? This will confuse the ECU into how much fuel to push through the injectors. But I would think that the engine light would come on then.

When it is doing its jerky thing and your foot is flat on the accelerator, does it push out black smoke?

Is there sufficient oil flow going to the turbo? I wonder if the turbo is spinning but as it gets hot it seizes up, then releases as it cools ( yeah this may be a bit far fetched but again I don't know that much about turbos either.) 

[Rumcajs]

Firstly is this manual transmission or automatic? It is not by any chance neutral switch on the transmission playing up?

Secondly, nothing screams more: "electrical fault" like this scenario, there is something (cable, plug etc) loose in the engine bay I reckon especially if it starts and runs well for 15-20 minutes. As everything heats up it also expands so to me I'd be checking for loose connectors, plugs, even loose battery cables ground especially.

The issue with 3 mechanics gets me though, embarrassing comes to mind. What kind of morons?????

I'd be checking following:

Battery leads/cables, alternator leads/cables, injection pump plug, engine earths/grounds.

if all is well there than I'll be checking body earthing/grounding as on Y61 (Patrol) it is poorly implemented and subject to easy fail.

Once these basics are established I'd be checking engine vitals to see what is happening:

So when it happens does the engine smokes? Misfires, running rough at idle or is it just not revving up in neutral first? Is it hard to start if turned off and restarted again immediatelly?

I'd observe accelerator pedal voltages, MAF voltages in both at idle and free revving then see if I can drive it. I'd observe turbo actuator moving upwards once engine is started....

Methodically I'd eliminate possible cause.....

Regards