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Help Please - petrol leak - now sorted


mr two
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Hi all

My Supe has been parked up for a couple of weeks...charged battery this morning, switched ignition on - and i saw petrol squirting across my engine bay quite badly- was going across the battery and headlight anyway. It was coming from a dome shaped unit at the top of the rear N/S just in front of the baulkhead. I think the main petrol feed goes in there doesn't it?..theres a thick fuel pipe coming from under the car to the underneath of the dome anyway.Not sure whereabouts on the dome that it was coming from though. i checked everything i could see but it all looked ok. petrol was "weeping" from same place. Dried it off, started engine and petrol slightly weeping from dome. Noticed there was a light flashing on one of the turbo gauges. switched off and I then traced the vacuum pipe ? that comes out the top of the dome and where it goes to was literally a loose fit., so much so that when i moved it slightly to check, it came off the metal pipe..i put that back on and switched ignition on again and it seems ok..

 

Any ideas please as i need to travel down the M6 tomorrow morning in her and obviously don't want a petrol leak !!

 

Thanks

D

Edited by mr two (see edit history)
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Guest Roger NE

You clearly have a loose or split petrol hose . . . so I DEFINITELY wouldn't be driving it in the morning ! You don't want a fire in the engine bay.

 

You need to investigate exactly where the problem is. The fuel line from the petrol tank goes to a Pulsation Damper fitted on the Nearside of the engine block, the output of which then goes up to the Vacuum Valve on the Fuel rail at the rear of the engine. (That's the dome-shaped thing you're on about)

 

There's another one at the other end of the fuel rail (at the front of the engine), which is the return feed of unused fuel back to the petrol tank.

Edited by Roger NE (see edit history)
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As above id be driving nowhere till that fuel leak is sorted especially as it squirting over the engine bay.

 

I ran the engine for nearly half hour after all of the above and no signs of any petrol leak..could it be a shut off valve somewhere that momentarily didnt regulate the fuel pressure properly ?..maybe with my car not being run for quite a few weeks ?

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Guest Roger NE

There's no shut off valve . . . a certain amount of fuel pressure is produced by the pump (depending on driving conditions, controlled by the ECU), but there is constant pressure pressure fed to the fuel rail while the engine is running . . . that's why the unused fuel at the other end of the rail is fed back to the petrol tank.

 

It's quite high pressure too . . . that's why it's potentially so dangerous. A small leak from a loose connector or a tiny split in a hose can very quickly turn into a big one.

 

You really need to check it all thoroughly (or have it checked, if you're not confident yourself, which it sounds like you're not)

 

With a hot engine, leaking fuel can ignite very easily. Quite apart from this happening while you're driving, even worse if you had the bonnet open looking for the leak, and petrol suddenly squirted onto your clothes, and ignited on the way . . . this has happened to people, and doesn't bear thinking about.

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There's no shut off valve . . . a certain amount of fuel pressure is produced by the pump (depending on driving conditions, controlled by the ECU), but there is constant pressure pressure fed to the fuel rail while the engine is running . . . that's why the unused fuel at the other end of the rail is fed back to the petrol tank.

 

It's quite high pressure too . . . that's why it's potentially so dangerous. A small leak from a loose connector or a tiny split in a hose can very quickly turn into a big one.

 

You really need to check it all thoroughly (or have it checked, if you're not confident yourself, which it sounds like you're not)

 

With a hot engine, leaking fuel can ignite very easily. Quite apart from this happening while you're driving, even worse if you had the bonnet open looking for the leak, and petrol suddenly squirted onto your clothes, and ignited on the way . . . this has happened to people, and doesn't bear thinking about.

 

If there was a loose connector or a split pipe,wouldnt the leak be evident all the time though ?..the squirting petrol happened when i 1st switched ignition on..i hadnt started the engine at that point..

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Guest Roger NE

Chris I presume the Dome thing he's referring to is the Vacuum Valve

 

Regardless of exactly WHEN the fuel leak happened, it shouldn't ever happen ! So it may not be apparent now . . . but obviously it is going to happen again at some point.

 

I wouldn't even ignore a Coolant leak that seemed to have stopped . . . because if it happens again it could cause the engine to overheat and resultant Head Gasket failure.

 

But a Petrol Leak could be FAR worse ! Even life-threatening . . .

 

So you really need to get all the lines and connectors checked properly before you drive it again.

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Sounds like an aftermarket fuel pressure regulator, the stock system uses no dome nuts, post a photo.

 

Hi Chris..i have taken a few pics but for some reason they won't upload onto here.

If you could PM me your email address i could email them to you no problem

 

 

Thanks

D

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Chris I presume the Dome thing he's referring to is the Vacuum Valve

 

Regardless of exactly WHEN the fuel leak happened, it shouldn't ever happen ! So it may not be apparent now . . . but obviously it is going to happen again at some point.

 

I wouldn't even ignore a Coolant leak that seemed to have stopped . . . because if it happens again it could cause the engine to overheat and resultant Head Gasket failure.

 

But a Petrol Leak could be FAR worse ! Even life-threatening . . .

 

So you really need to get all the lines and connectors checked properly before you drive it again.

 

Thank you for your time on this Roger

I have just been having a good look at everything it is possible to look at and i really cannot see any dodgy petrol pipes and all connections are tight. I have just switched the ignitiion on to start the pump and there are no leaks at all..I am totally baffled as to what has happened.

Should there be a slight " hissing" noise from the dome ? i can hear a slight hissing from it whilst the pump /ignition is on.

And as i have said- i have had the engine running for almost half hour and cannot see any sign of a leak.

I think like you - it has happened once so until i have an answer as to why, it can happen again and so therefore i cannot use the Supe. Really annoying me now.

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Guest Roger NE

The hissing may just be the rushing sound of the fuel coming through . . . but if it sounds more like air you may have a Vacuum pipe leak

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As Ian so rightly says, someone has b***ered about with things and fitted a cheap and nasty fuel pressure regulator, get a stock one and associated plumbing and return it to stock. The only fuel pressure regulators one should consider instead of stock have "Bosch" written on them ;)

 

TYhat sort of pipe with hose clips is NOT suitable for a modern FI system, just bin the thing :)

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As Ian so rightly says, someone has b***ered about with things and fitted a cheap and nasty fuel pressure regulator, get a stock one and associated plumbing and return it to stock. The only fuel pressure regulators one should consider instead of stock have "Bosch" written on them ;)

 

TYhat sort of pipe with hose clips is NOT suitable for a modern FI system, just bin the thing :)

 

Where can i obtain a stock regulator and associated plumbing from ? and do you have any pics of one please?I just thought this one was standard

Thank you for your time btw.

Why do you think it has been changed? and where does the one i have leak from?

 

D

Edited by mr two (see edit history)
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Guest Roger NE
Where can i obtain a stock regulator and associated plumbing from ?

 

Hopefully secondhand, from a scrap car . . . as new from Toyota would be rather expensive !

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  • 1 month later...

I am sorry I was called away and could not be here to hand the key over. Thanks for the thumbs up, much appreciated. I think you should be fine now. I was goimg to mention the wiring to the under car lights, it's not too, err, tidy, but shouldn't cause an issue. Put it on the "to do" list :) If you decide to have the in car fuel pressure gauge made working I should have all the info to make it a while you wait job, given time to get the parts in. All the best.

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I am sorry I was called away and could not be here to hand the key over. Thanks for the thumbs up, much appreciated. I think you should be fine now. I was goimg to mention the wiring to the under car lights, it's not too, err, tidy, but shouldn't cause an issue. Put it on the "to do" list :) If you decide to have the in car fuel pressure gauge made working I should have all the info to make it a while you wait job, given time to get the parts in. All the best.

 

Thanks Chris...Yeh i noticed the under-car lights wiring wan't the neatest,lol!!..i will take Supe to my sons soon as and get it over the pit in his garage and sort out the wiring.

As regards the fuel gauge - would it be possible to PM/email me a cost please ?

 

Regards

Dave

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