2001 Toyota KZ-TE 3L

To add to my woes, while I was giving my loser nephew a guided tour of the Pilanesberg my old (2001) Toyota double cab went into 'get you home' mode with a loud stochastic rattle coming from the engine and the engine light on. We made it home finally, 2nd gear on the hills!
Investigation seems to indicate that the variable diesel pump time is not working. I've identified a driver transistor and resistor burned out in the computer. The transistor I can source when I next go to Pretoria, the resistor is a problem, the computer uses 2 values, either 10ohm or 100ohm, does anyone know what the value might be, or where to find out? I've tried all the sites that Google throws at me from this side.
As an aside, Toyota want 1,400 quid for a new one (computer) and good second hand ones with no guarantee start at 200quid (if you can find one) which I frankly don't have.

Put a 100 ohm in, and suck it and see - or temporarily put a pot in, set high, then gradually back it down until the computer fires up.

A pot won't cut it for power reasons. But yes, exactly what I was going to do, after I've checked to make sure there's no earth fault on the pump side! I just hoped that a search from a UK based searcher may throw up some alternative answers.

Eric wrote: Put a 100 ohm in, and suck it and see - or temporarily put a pot in, set high, then gradually back it down until the computer fires up.

The computer is firing up, it's just that the pump gets no advance or retard signals.

In that case, then, if you have a sillyscope (and I imagine you do!) - monitor the pump output from the computer, and see if there's anything coming out! That might help you to locate the problem, or the right values for the fried components.
Do you know what happened to cause them to fail?

I would agree with Eric that unless you can identify what caused the components to fry just replacing them may only provide at best a short term solution.

I decided to make this a new topic.I've discovered that the stochastic knock is due to incorrect pump timing. There is no pull up condition coming from the computer. The Collector of the transistor is connected to 12volts, the Emitter is connected to a resistor (value unknown) which acts as a pull up to a solenoid in the pump.
I find the burning out of the resistor and transistor odd since if the transistor failed the resistor wouldn't. The only way I can see this happening is if an earth fault occurred in the pump, pulling the computer output down to ground. It's a 1watt resistor so if it was 10ohms that's 19.6watts at 14volts = goodbye resistor! The transistor is good for 15amps but under a continual pulsed load and 44^oC (the temperature in the park that day) I can see why the transistor would also wave goodbye cruel world.
Therefore, as Simon suggests, replacing the faulty components will at best, only be a short term solution. If the resistor was 100ohms the power dissipated would be 1.4Watts, probably enough to discolour it but not enough to burn the paint coating off!
Thanks guys for participating in this discussion, it has helped clarify my thinking, I was going to do a rudimentary check of the pump but now I think I need to be more proactive. I just need to wait for sissy to locate the components.

We had rain yesterday so it's a bit cooler today, I decided to attack the wiring of the pump to no avail! Then I tested the continuity from the computer to the pump, I got continuity for all wiring except, you guessed it, the connection from the burned resistor to the pump! Back at the pump I eventually found a connector buried underneath the pump with the correct wire colours on it! One of them was burned off.

I believe it's the connection to the timing solenoid.

So either it has been chafing, or something has got very hot, and melted the insulation back - hence a nice short-circuit!
Poof!
:evil:

Or the timing solenoid is shorted internally!
Surprised it is not fused.

I think the resistor is supposed to be a current limiter in the event of a short. I'd rather this than the Landrover solution of fusing everything! Someone in the long forgotten past used a piece of galvanised wired to stop the plug from slipping off the solenoid! Time and vibration did the rest. I might add, this car has obviously been in a number of accidents, I would never have bought it but when our 1990 model Hilux 4x4 was stolen (from outside the Magistrates Court!) I needed a vehicle. This was offered to me by a Tenant as part payment for a loan. I obviously wasn't going to get the money back, (and never did!) So it seemed like a good idea at the time.

And now Hey mister CAN YE FIX IT?

I've managed to strip the insulation back and solder the wire on.

Then I'll put some Heat shrink to give it some support.
I then put the plug on the pump and measured the resistance from the computer end, 11.2ohms, damn, the on line manual says it should be 20ohms. New solenoid on order, only 200pounds!

Ouch! But at least you can now be pretty certain why the resistor burnt out.
Like many things in mass production cars I would be willing to bet that it was not long before Toyota knew the solenoid was prone to failure and may have even improved it on the production line but tell everyone and recall all the suspect stock? I don't think so!
A bit like Mazda recalling cars in the US because of "spiders in the petrol tank which could cause the tank to split". I suspect it was really a faulty tank air non return valve that could cause the pump to collapse the tank but that would reflect of Mazda's technical ability rather than just be an act of nature.

Interestingly later models of this engine became the 5L where it's a cable accelerator and purely mechanical pump. For about 1,200pounds I can get this engine modified with a 5L pump. It's a common modification further north where 1st world technology is not available.