Hi I have installed a fuel pressure reg today and I have got a high flow exhaust and intake now the standard reg has a Max pressure of 300 kpa (46psi) can I turn it up to around 55psi for a standard map I know with out a remap it has no major effect but will it make some difference with a standard fuel pump ?
Fuel setting
- Thread starter mrjackmich96
- Start date
OP
OP
Found it bogged out very quickly so pit back to standard for now as blew water pump and think head gasket has slight leak and I know chain is slack ... Service work first 
frank
Club Member
which is why you need a proper rising rate reg (4:1 ratio)
OP
OP
Rising rate you mean vacuum on open throttle yeah ?
frank
Club Member
sort of, the CG,s lean out in the mid to high rpm, and jacking the fuel pressure (or bigger injectors) cause overfueling lower down.
my rr f/p/r held the fuel pressure down to 1.5 bar @ low throttle/high mani vacuum, and 3 bar @ wot
OP
OP
Ahh I see so instead of more pressure through out have it more towards top end ?
frank
Club Member
yeh, but going by previous dyno printouts the mixture goes mega rich at the very top, so some sort of max fuelflow control might help (lower pump voltage or whatever)
all pretty ghetto, but still an option for N/A tuning
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OP
OP
What for did you use because mine was given to me by a friend for a job I did for him and its not too clever
OP
OP
Fpr*
frank
Club Member
mine was a diy one, a big diaphragm from a mini dizzy fitted to a coilpack stock f/p/r ( the filter in the pic was acting as a damper)
euromicra used a 20:1 one iirc, called an f/m/u (fuel management unit)
i did try an ebay one that was listed as 1.7:1 ratio, but when i tested it, it only dropped the fuel pressure (vacuum pipe connected) half a bar like the stock one
euromicra used a 20:1 one iirc, called an f/m/u (fuel management unit)
i did try an ebay one that was listed as 1.7:1 ratio, but when i tested it, it only dropped the fuel pressure (vacuum pipe connected) half a bar like the stock one
OP
OP
Wow ... Now that looks complex ... Think I need to do some research then
frank
Club Member
nahWow ... Now that looks complex ... Think I need to do some research then
the stock f/p/r is just a diaphragm with a spring on top (regulating a 3 bar rail pressure), and the vacuum pipe tries to pull the spring off the diaphragm (which drops the rail pressure to 2.5 bar (to stop the engine from sucking the fuel out of the injectors @ low throttle/high mani vacuum)so if you cut the top off the f/p/r and remove the spring the rail pressure will be near zero, and if you fit a sealed diaphragm on top it will push or pull the rail pressure up or down (bigger size diaphragm = bigger push/pull)
OP
OP
I see why you made your own now :/ that's £100 is too much for me :/
frank
Club Member
aye, blingy tho aint they
it suffers from the same limitations as a map sensor, ie very little resolution between 1/4 throttle and wot (the zero mani pressure zone) but it certainly cures the bogging down @ low throttle you get with big injectors.
on mine i got a sub 10:1 a/f/r (bumping along the bottom of the graph) and a column of black smoke from the tailpipe from start to finish on the dyno (vid on here somewhere)
if i had fitted some smaller injectors the a/f/r,s would probably have been ballpark
Hey there,
Would like to know, if you do, what's the ampere output of the fuel pump for the 1996 Nissan Marche/Micra. I got a reading of 4.5/4.6 AMPS. Im trying to solve a fuel system issue.
Would like to know, if you do, what's the ampere output of the fuel pump for the 1996 Nissan Marche/Micra. I got a reading of 4.5/4.6 AMPS. Im trying to solve a fuel system issue.
