fuel pressure gauge position

[arjunior45]

I'm going to mount a fuel pressure gauge and I wander if the position in this picture is a 'safe' one, concerning heat or any other risk. It is in front of the ignition modules.

Do I need a 0 - 100psi {7 bars} one or a 0 - 60 psi {4,2 bar} will be better - more accurate?

Nick

[wrinx]

I've got one that fits inside the cabin but the pressure bit still goes inside the engine bay...so am also interested in this subject :D

That looks like a safe location, or as good as it gets...where are you cutting in to the fuel line?

No idea about accuracy of the two gauges, I guess you'll only be going to 3b pressure or thereabouts so either would do. Is there much of a price difference?

wrinx

[arjunior45]

...where are you cutting in to the fuel line?

No idea about accuracy of the two gauges, I guess you'll only be going to 3b pressure or thereabouts so either would do. Is there much of a price difference?

wrinx

I'm going to cut the fuel line at the point recommended by the workshop manual {Q4fuel.pdf and page 32} for 'checking pressure and sealing of the fuel system', from the 'manifold suppling fuel to the injectors'.

As for the price, both {4,2 and 7 bar max} have the same price.
Accuracy? I do not know. They claim it is very accurate, but I'll check it with my mechanics mercuric gauge.

Nick.

[jimnielsen]

Thats about the same position as my gauge. It has worked fine there.

jimn~

[axaQ42]

I've got it under the climate control with company of the EGT gauge and fan switch :)
http://i89.servimg.com/u/f89/11/79/45/12/photo010.jpg

[arjunior45]

@ axaQ42,

I do not want to have this gauge inside the 'cockpit'. It's a mechanical one, so I do not like that much having fuel next to my feet. From the other hand I'll use this space {under the radio} for my turbo timer with some other gauges {turbo boost meter, EGT meter, differential temp meter, intake air temp meter and AFR meter} incorporated.

@ jimnielsen,
last night I had a second thought. The hose from the injectors manifold to the position in front of the ignition modules will be quite long and as far as I can imagine this hose will be heated by the intake manifold heat. Am I wrong?


An alternative position can be at the injectors manifold 'intake' point! All I'll need will be a proper T piece {if I'll be able to find one} and the gauge WITHOUT any hose at all. See picture.
What do you think of this position?

Nick

[jimnielsen]

I think that alternative position would be fine, but, its more complicated to implement - you really need a 'T' piece with the correct threads and the in the correct orientation without any 'adapters' or the whole thing will be too messy. The rubber hose connection I have on mine is about a foot long. I'm not too concerned about the hose being heated, but I will make sure i keep it as far away from heat sources when I put the whole thing back together...

[arjunior45]

I'll give it a try Jim.
The 'T' piece is my concern too but I believe something will come up, without any adapters. All I need is a 'T' piece with male end on one side and female on the other. The same 'T' piece I'll need for the 'hose connection' as well, don't you think?

BTW, do you remember the threads dimensions - data from the one you're using?

Nick

[jimnielsen]

unfortunately you may find that there are metric fine threads on the fuel rail and bsp threads on the gauge. I am using M12x1.25 threaded sensors on my engine (for the datalogger) and its very hard to find brass fittings with metric threads (at least here...)

[arjunior45]

here in Greece we use only metric system and if I can't find one, I'll ask them to make one for me.
Is the M12x1.25 the thread on the fuel rail {injectors manifold}?
Did you have any problem with the length of the hose that goes to the fuel rail?

Nick

[AlfaJack]

If they can not make it then this place is great for adaptors:
http://www.merlinmotorsport.co.uk/FUEL-SYSTEMS/c26/index.html

[arjunior45]

I was thinking for something like this, to mount it to the injectors manifold {rail} and mount the fuel pressure meter directly on top of this, without any tubes at all. Orientation must much though. Hopefully, I'll find something to do the job.

Nick