Diesel Pump Cut-Off Solenoid Problems

[mothpoulsen]

I have a 2.0 diesel engine, from 1997 (not D-4D) that will not start when warm but starts easy when cold. It cranks, but gets no fuel.The diesel pump cut-off solenoid (which have other functions than just cut-off I think) clicks fine when cold but not when the engine is warm.

The engine runs fine for hours when I start it cold, - I can restart it if I try immediately after stopping, but waiting 10 sec will result in same problem.

Here is what I have done/tested: new fuel filter, pumping when cranking, no fuel at injectors when cranking hot. New (second hand) solenoid. blocking return hose does not help and neither releasing possible vacuum at he fuel tank..

There is absolutely no hesitation when starting cold, so my verdict is an electrical inhibition of the cut-off solenoid when the engine is warm. Is it the relay (and which one is that?) or a heat sensor, that prohibits the solenoid to operate? Please help asap - I have only a week to solve the problem.

[mothpoulsen]

- Forgot to say - When engine is hot, - no clicks at solenoid but applying 6V to the terminals makes the warm solenoid click fine - so no problem with the solenoid. (I first tested the glow plugs - no problems.) Can an immobilizer function play a role?

I know this is a question for hard core auto electricians - I hope we have one here at the forum who can help.

Thomas Danish

[mothpoulsen]

Is there really no one in this international forum, who knows just a little more than tire pressure and which engine oil is best?

[mothpoulsen]

-No help in this forum - I'm pretty disappointed. I have a vintage Jaguar E. The Jaguar forum knows what they are talking about.

Can anyone just send me a wiring diagram on the diesel pump? 2.0 TD from 2097 - same as in Corolla and Sports wagon (pre D-4D engine)

[Devon Aygo]

Your engine was very rare in the UK and its quite possible that there is no one on the forum with the engine and even less likely they have had the same issue as you.

Technical information can be purchased through www.toyota-tech.eu

And your poor attitude is most likely to annoy people rather than prompt them you to assist!!

[yossarian247]

Rather than spend a lot of time trying to track down the original fault it may be more straightforward to simply find an ignition-switched positive feed in the fusebox and run a new lead direct to the solenoid, thus bypassing whatever is causing the problem.

I agree with the above though, bullying people on forums into helping generally doesn't work!

[mothpoulsen]

Thanks for the advice Yossarian - the problem is just, that I have read somewhere that this solenoid has not just an on-off function, and that 12 V will fry it if applied for more than a short try.

Regarding comments from the moderator, I apologize if I have offended anybody. I just felt, that if 384 persons had read a specialized thread on cut-off solenoids, someone might be in a position to give a hint. I have had six Toyotas - bought and serviced my mothers and my mother in laws. I have changed engines, drive axels, gearboxes, main bearings, honed cylinders and all mechanic work on the cars - just by reading Haynes and a bit more. Maybe it is just not the right forum for specialized issues like this.

[yossarian247]

I think the problem is that you have a relatively rare car, which is even rarer because it's nearly 18 years old, with quite an unusual fault. The chances of anyone on here knowing the exact cause of the fault must be fairly low! I'm sure that if anyone could have replied with a definitive answer to your problem they would have done. I find this forum a bit less 'techie' than some other car forums I've frequented, but perhaps that's just because Toyotas are too damn reliable!

Anyway back to your problem. Is the solenoid supposed to operate at 6v as far as you know? If so then there are plenty of 12v to 6v converters for sale on eBay and similar for less than £5. Could be worth trying?

[vincentfishing]

dont know if your car has a camshaft sensor and ecu, but i know that on bmw diesel engine when they fail, its common for them to start when cold and not start when hot which is similar to your problem, also once the car is startd the ecu ignores the cam sensor so a test is to fire up the engine when stopped hot with easystart, if the car starts and runs the cam sensor is duff, might have absolutely no relation to your car , but who Knows, a usefull bit of info anyway, good luck.

[mothpoulsen]

To Yossarian - I'm not at all specialist on solenoids, - I have operated this both with 12 (short) and 6 V - the 6V only not to fry it. I think I have read somewhere, that the solenoid probably operates over a range of voltages - maybe not only on and off, so I'm not sure it is the right avenue - maybe combined with the suggestion of Vincent (could apply 6V shortly only to start the car).

To Vincent: I think it has ecu (the relay in the fuse box says so), and funny enough, I think I had a BMW diesel some years ago with the same problem. Your suggestion sounds very interesting - and easy to try. I'm working in Turkey, and my car is in Denmark - so I will try it as soon as I come home. Thanks to both of you.

[vincentfishing]

Make sure you let us know how you get on, its always nice to hear the final solution even on an 18 yr old car, i drive a 15yr old rover 75 (with bmw 2.0 diesel engine) a great / very cheap to buy car, that is until i get another engine in my 2005 previa.

[mothpoulsen]

I will - also notice, that in Denmark the tax on cars is 180% !!! -, so even an 18 years old car is worth while preserving.

[mothpoulsen]

This is what I found on "ehow":

"Unlike a regular solenoid valve, diesel fuel shut-off solenoid coils are attached to
sensors that are capable of receiving and interpreting electronic signals from
the machine's main electrical system. If the sensors detect a dangerous problem
with the machine's operations or engine, the electrical signal running to the
solenoid coil will automatically shut off."

Unlike a regular
solenoid valve, diesel fuel shut-off solenoid coils are attached to
sensors that are capable of receiving and interpreting electronic
signals from the machine's main electrical system. If the sensors detect
a dangerous problem with the machine's operations or engine, the
electrical signal running to the solenoid coil will automatically shut
off.

Read more : http://www.ehow.com/how-does_5016171_diesel-fuel-shutoff-solenoids-work.html

Unlike a regular
solenoid valve, diesel fuel shut-off solenoid coils are attached to
sensors that are capable of receiving and interpreting electronic
signals from the machine's main electrical system. If the sensors detect
a dangerous problem with the machine's operations or engine, the
electrical signal running to the solenoid coil will automatically shut
off.

Read more : http://www.ehow.com/how-does_5016171_diesel-fuel-shutoff-solenoids-work.html

[mothpoulsen]

Sorry for the duplications

[yossarian247]

A bit of googling suggests that your car will probably have the 2c-te engine which didn't actually have a cut off solenoid as such, but a 'fuel spill valve'. As you thought, that is a bit more sophisticated than a traditional cut off solenoid and probably more like the suction control valve used on some common rail systems. I'm not sure that information helps you much but at least you know what you're dealing with!

[mothpoulsen]

I think I came across that name "fuel spill valve" somewhere also, so you are probably right. It's an important information - Thank you!