Fuel pump / fuel pipe issue???
Discussion
After changing the fuel pipe on the 450 for 10 bar re-inforced injection rated fuel pipe, I have noticed that the pipe has gone hard - oh-er.
I know it has been advised to go for 12 bar but 10 bar comes out at around 150 psi which I would have thought would have been fine.
I also had an incident of the pipe coming off the fuel pump connector and the fuel rail inlet on the engine even though I tightened up the jubilee clip extra tight. The car runs fine but I keep on having fuel pipe issues.
Question: When I had the car originally I found a resister on the footwell floor that had come / fallen out of the fuse box pack.
Could this be for the fuel pump to 'tame' it a bit? If so, could this be causing me issues with too much pressure in the fuel pipe thus causing me the leaking, connections coming off issues that I have been having?.
Also has anybody else had any issues with fuel hose going brittle, hard or generally playing up or is it just me??
MikeB
I know it has been advised to go for 12 bar but 10 bar comes out at around 150 psi which I would have thought would have been fine.
I also had an incident of the pipe coming off the fuel pump connector and the fuel rail inlet on the engine even though I tightened up the jubilee clip extra tight. The car runs fine but I keep on having fuel pipe issues.
Question: When I had the car originally I found a resister on the footwell floor that had come / fallen out of the fuse box pack.
Could this be for the fuel pump to 'tame' it a bit? If so, could this be causing me issues with too much pressure in the fuel pipe thus causing me the leaking, connections coming off issues that I have been having?.
Also has anybody else had any issues with fuel hose going brittle, hard or generally playing up or is it just me??
MikeB
Some of those symptoms could be caused by having massive excess fuel pressure. Is it possible the return pipe has got kinked or blocked, or even 
the feed and return are connected back to front or something like that? If you're running on unleaded you also need to ensure that all the hoses are compatible with unleaded.
the feed and return are connected back to front or something like that? If you're running on unleaded you also need to ensure that all the hoses are compatible with unleaded.From memory (as I am sitting in work! - working hard of course) The 'feed' pipe from the pump connects from the pump to short length of pipe, this then connects to a length of metal pipe that runs the length of the car to the front wheel arch.
This then connects to another short length of petrol pipe that comes out into the engine bay and then connects to the fuel rail.
The 'return' connects from the fuel pressure regulator on the engine and travels back the whole length of the car (in the rubber? 10 bar petrol pipe) until it gets to the top of the petrol tank to return any unused petrol.
It is slightlly kinked at this point due to the acute angle of the newly fabricated (by previous owner) alloy petrol tank connector.
Could this be the issue?. Or is it something to do with this mysterious resister?.
MikeB
This then connects to another short length of petrol pipe that comes out into the engine bay and then connects to the fuel rail.
The 'return' connects from the fuel pressure regulator on the engine and travels back the whole length of the car (in the rubber? 10 bar petrol pipe) until it gets to the top of the petrol tank to return any unused petrol.
It is slightlly kinked at this point due to the acute angle of the newly fabricated (by previous owner) alloy petrol tank connector.
Could this be the issue?. Or is it something to do with this mysterious resister?.
MikeB
mikeb said:
After changing the fuel pipe on the 450 for 10 bar re-inforced injection rated fuel pipe, I have noticed that the pipe has gone hard - oh-er.
I know it has been advised to go for 12 bar but 10 bar comes out at around 150 psi which I would have thought would have been fine.
I also had an incident of the pipe coming off the fuel pump connector and the fuel rail inlet on the engine even though I tightened up the jubilee clip extra tight. The car runs fine but I keep on having fuel pipe issues.
Question: When I had the car originally I found a resister on the footwell floor that had come / fallen out of the fuse box pack.
Could this be for the fuel pump to 'tame' it a bit? If so, could this be causing me issues with too much pressure in the fuel pipe thus causing me the leaking, connections coming off issues that I have been having?.
Also has anybody else had any issues with fuel hose going brittle, hard or generally playing up or is it just me??
MikeB
Do the hoses only seem hard because they are full of pressurised fuel? The regulator should keep the pressure in the fuel rail to something like 36/40 psi. If you've got an adjustable one, has someone tweaked the pressure up to cope with some engine mods? I think even the non-adjustable versions can be bodged to raise pressure. I've recently changed some of my hoses for SAE 100 R6 rated at 400 psi, and they still seem as flexible as they were before fitment. What's the tech. spec. of your hoses (SAE etc.)?
Hi guys,
The hoses are standard un-leaded injection compatible reinforced 10bar petrol hose.
Once fitted, after a few weeks the hose sort of goes hard and retains its shape. For instance where the jubilee clip tightens around the end of the hose after a few weeks this goes hard and you then can no longer tighten up the clip anymore.
The hose also looks different fron some of the original hose that never got fitted. you can make out the pattern of the reinforcement inside the tube. Something is up.
i don't know if its the slight kink in the return hose, the fuel pump over pressurising etc. i doubt if its the regulator as this looks like the standard non adjustable jobbie to me.
Where did you get the higher spec hose from?.
MikeB
The hoses are standard un-leaded injection compatible reinforced 10bar petrol hose.
Once fitted, after a few weeks the hose sort of goes hard and retains its shape. For instance where the jubilee clip tightens around the end of the hose after a few weeks this goes hard and you then can no longer tighten up the clip anymore.
The hose also looks different fron some of the original hose that never got fitted. you can make out the pattern of the reinforcement inside the tube. Something is up.
i don't know if its the slight kink in the return hose, the fuel pump over pressurising etc. i doubt if its the regulator as this looks like the standard non adjustable jobbie to me.
Where did you get the higher spec hose from?.
MikeB
MikeyB
Have a chat with Dave at this place www.motorsport-plumbing.co.uk/
I spoke to him Saturday re. BBWF (he deals in race spec plumbing and more.
Have a chat with Dave at this place www.motorsport-plumbing.co.uk/
I spoke to him Saturday re. BBWF (he deals in race spec plumbing and more.
Had a word with Dave, sounds promising but seen this in the meantime.....
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=15271&item=4554312446&rd=1
Any thoughts as to it's suitability????
MikeB
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=15271&item=4554312446&rd=1
Any thoughts as to it's suitability????
MikeB
mikeb said:It says 25 bar for air. asuming that's the same for fuel then it's well over the top. Is it suitable for unleaded? I think the closest fuel used in planes is 100RON leaded, great stuff if you can get your hands on it but the fuel line specification probably doesn't cover unleaded. IMHO it could be fine/better but 'cause I'm chicken I'de stick to known safe stuff that's recommended for fuel injection systems.
Any thoughts as to it's suitability????
My 2p for what it's worth
Leo
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