Discussion
I have suffered a few petrol leaks over the 13 years ownership, from the plenum return to the tank line. It leaks at the junction between the rubber hose from the plenum where it joins the copper tube to the rear by the side of the gearbox. After tightening the fuel clip the problem normally goes away.
This is unexpected as the high pressure line feeding the injectors has never leaked always the low pressure return to the tank. The latest leak was yesterday while starting the car after its winter snooze. It suggests a pressure build-up.
Have decided to fix it properly as several cars seem to have been lost through spontaneous combustion.
Made up a pressure guage and measured the injector feed at 35psi, so fine. The return to the tank feed was about 3-4 psi so also fine. So where is the problem? The return line is free when blown through so not the cause of a pressure buildup perhaps the pressure regulator has an intermittent fault, has any owner experienced this?
While looking at the fuel runs:
Steel feed from the tank,rubber hose to the fuel pump,rubber hose to the filter,rubber hose to the copper pipe, rubber hose to the injectors (8 connections) By having a single Goodridge type Nitrile hose from the filter all the way to the injector rail would reduce this to 6.
On the return feed: Short rubber hose from the pressure regulator to short steel pipe, to rubber hose, to copper pipe by the gearbox, to rubber hose, to tank return. (6 connections) by running a Goodridge hose from the tank straight to the pressure regulator reduces this to 2!
Why is the short steel tube necessary at all? To replace the short rubber hose on the regulator you need to remove the plenum anyway so the longer rubber hose from the copper pipe by the gearbox might as well go straight into the regulator! Is this a hangover from Landrover?
A few weekends ago I replaced the exhaust gaskets, another interesting job! See:
www.bertram-hill.com
This is unexpected as the high pressure line feeding the injectors has never leaked always the low pressure return to the tank. The latest leak was yesterday while starting the car after its winter snooze. It suggests a pressure build-up.
Have decided to fix it properly as several cars seem to have been lost through spontaneous combustion.
Made up a pressure guage and measured the injector feed at 35psi, so fine. The return to the tank feed was about 3-4 psi so also fine. So where is the problem? The return line is free when blown through so not the cause of a pressure buildup perhaps the pressure regulator has an intermittent fault, has any owner experienced this?
While looking at the fuel runs:
Steel feed from the tank,rubber hose to the fuel pump,rubber hose to the filter,rubber hose to the copper pipe, rubber hose to the injectors (8 connections) By having a single Goodridge type Nitrile hose from the filter all the way to the injector rail would reduce this to 6.
On the return feed: Short rubber hose from the pressure regulator to short steel pipe, to rubber hose, to copper pipe by the gearbox, to rubber hose, to tank return. (6 connections) by running a Goodridge hose from the tank straight to the pressure regulator reduces this to 2!
Why is the short steel tube necessary at all? To replace the short rubber hose on the regulator you need to remove the plenum anyway so the longer rubber hose from the copper pipe by the gearbox might as well go straight into the regulator! Is this a hangover from Landrover?
A few weekends ago I replaced the exhaust gaskets, another interesting job! See:
www.bertram-hill.com
Hi , tried the link to your exhausts and it don't work ? All the others do :-) nice site keep it up , another interesting thing to know when i swaped my exhaust manifolds years back with new gaskets I striped a thread I made a short tap to tap it out to the next size yes without drilling as no space !! Time and patience it done the job ;-) I found the tap the other day on my tool box I will find out what the size was that would be helpful to someone knowing they don't have to remove the whole system and possibly the head !!
Ste .
Ste .
It's my guess the swap to copper is for a couple of reasons
Cost.
Longevity of copper
Space
1 and 2 speak for themselves.
The gap between the chassis and body in a couple of places is very tight! And then you have the fuel line to squeeze in too. Also the copper crosses through the chassis and runs up the inside of one of the diagonal rails, that would be a big lump if done in rubber, let alone braided, whereas with copper you can bend it and keep it really close to the chassis.
What clips are you using on the hose to copper connections? They have to be fuel line specific.
Cost.
Longevity of copper
Space
1 and 2 speak for themselves.
The gap between the chassis and body in a couple of places is very tight! And then you have the fuel line to squeeze in too. Also the copper crosses through the chassis and runs up the inside of one of the diagonal rails, that would be a big lump if done in rubber, let alone braided, whereas with copper you can bend it and keep it really close to the chassis.
What clips are you using on the hose to copper connections? They have to be fuel line specific.
Loubaruch said:
I think I must have a faulty pressure regulator
Hi mate...You shouldn't have a pressure build up on the low pressure side...Does the Griff have an atmospheric fuel tank breather like the Wedge?....If so make sure that is not blocked, Ours are down by the N/S rear wheel so can pick up crud.Was the 35psi the idle pressure?..Did you measure the WOT pressure, This is done by either disconnecting or clamping the small vacuum pipe from the plenum to the FPR..If you have a solid state FPR then they can fail as the diaphragm can become weak especially if its the original...But then it wouldn't maintain pressure and you would notice when driving it if that was the case...You would definitely smell it out the exhaust and almost double the pops and bangs..Possibly flames out the tailpipe...Running too lean is NOT good but neither is too rich...A couple of psi over means less MPG but you get a couple more horses...Although it might fail an MOT.
Not sure what the griff fuel pressures are but the Wedge 3.5ltr is around 24-25psi on idle and 36-38psi on Wide Open Throttle...I changed from the standard solid state FPR to a Sytec adjustable with fixed pressure gauge, It does help to diagnose certain things and is a good way of monitoring/Adjusting what is happening..Especially if you have it on a Dyno.
Be careful if you go this route though as there is a great risk of encouraging too much fiddling with fuel pressure..
Guilty as charged your honour...
...
Thanks, some useful info there.
The cat equipped Griffith's have a sealed tank that vents to a carbon cannister when the engine is not running. When up to speed a purge valve opens and the petrol fumes from the carbon cannister are pulled into the plenum to be burnt.
I measured the injector fuel pressure at idle and blipping the throttle it stayed around 35 psi and the return feed around 3-4psi. The return line is not blocked so a bit of a mystery as to why the fuel leaked but its always at the same place. The FPR is the standard Rover V8 mechanical device.
I am replacing the complete fuel lines at the weekend so then just a single SS braided hose from the tank to the return union on the FPR and see how it goes. The only places then for a leak are either the FPR connection or a boot full of fuel.
Will report progress.
The cat equipped Griffith's have a sealed tank that vents to a carbon cannister when the engine is not running. When up to speed a purge valve opens and the petrol fumes from the carbon cannister are pulled into the plenum to be burnt.
I measured the injector fuel pressure at idle and blipping the throttle it stayed around 35 psi and the return feed around 3-4psi. The return line is not blocked so a bit of a mystery as to why the fuel leaked but its always at the same place. The FPR is the standard Rover V8 mechanical device.
I am replacing the complete fuel lines at the weekend so then just a single SS braided hose from the tank to the return union on the FPR and see how it goes. The only places then for a leak are either the FPR connection or a boot full of fuel.
Will report progress.
Mmmm...Interesting fuel system...The canister sounds like its acting like an accumulator which was fitted to the K-Jetronic systems of the V6 Tasmin's...Whereas it would hold the fuel pressure after turning off the engine to aid hot starting, Although it would fall away overnight...
Sounds like it could be either a damaged hose..They can fail from the inside out....Good quality hose and clips are a must, Especially with the added amount of ethanol in modern fuels...Not sure that braided fuel lines are good?..The only problem with them is that you only know its leaking when fuel is pi55ing out as any splits cannot be seen...They look good in the engine bay for air or oil..And there are some high quality oil braided hoses that are the dogs...
After paying someone reputable who works with TVR's to replace all my fuel rail hoses i have had a puddle of fuel in the Vee on occasions....
...After going over all the clips i found that the ones used are slightly too big..People seem to think that its the opening size thats important and sometime oversize...Errr...No its the closing capabilities of the clip as that is its major function...I still get a small weeping from the hose on the front fuel rail but its so awkward to get to and once the engine is running stops to be of a main concern...However i will have to re-do it myself...Which is annoying after paying top dollar to have a so called pro do it...
"DO IT ONCE-DO IT RIGHT"......Hope you sort it.....Cheers...Ziga
Sounds like it could be either a damaged hose..They can fail from the inside out....Good quality hose and clips are a must, Especially with the added amount of ethanol in modern fuels...Not sure that braided fuel lines are good?..The only problem with them is that you only know its leaking when fuel is pi55ing out as any splits cannot be seen...They look good in the engine bay for air or oil..And there are some high quality oil braided hoses that are the dogs...
After paying someone reputable who works with TVR's to replace all my fuel rail hoses i have had a puddle of fuel in the Vee on occasions....
...After going over all the clips i found that the ones used are slightly too big..People seem to think that its the opening size thats important and sometime oversize...Errr...No its the closing capabilities of the clip as that is its major function...I still get a small weeping from the hose on the front fuel rail but its so awkward to get to and once the engine is running stops to be of a main concern...However i will have to re-do it myself...Which is annoying after paying top dollar to have a so called pro do it..."DO IT ONCE-DO IT RIGHT"......Hope you sort it.....Cheers...Ziga
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