Rob_DOHC

iTrader: (4)

With out adjusting fuel pressure you will be limited to making fuelling adjustments based on the CO adjuster alone, You NEED to adjust the fuel pressure as Karlos has described. As Stu points out you will be making stockish power without adjusting the fuel pressure properly OR simply melt things. Do you get fast ford in Lux? if you do there were a few issues a couple of years ago that explained the inner workings of the MFI units pretty well..... I think it may even have been written by Stu!!??

On MFI most cars seem to make 180-200bhp with between 16 and 20 psi of boost with a stage 2 t3. I would suggest you start at your waste gate pressure (probably 7psi) and work up adjusting the fuel pressure as you go. Keep RPM sensible (6500 max)

For over 15psi with your car and lack of tools go rich rich, like 10.5 afr. Really you should be at 11.5(ish) at 15psi but I just don't think this will be safe for you with no det cans! You will probably want to retard the timing a little from the stock figure too (to begin with anyway).

You can also take a manifold vac feed to the fuel pressure regulator (the smallish cylinder hanging off the side of the MFI unit). This will help to even things out a little, leaner off boost, richer on boost.

Take some pictures of your engine bay and we can point you at the right bits.

Rob,

Ben26

Those write ups Stu done in fast ford are on his website and are a very good read.
Motorsport developments Lux

luxembourgrst

yes thanks rob very interesting

ok i need to have 11.5 on afr on full boost if my turbo charge more then 15 psi .. thank you

also interesting with the vacum feed i only need to put a connection from the manifold like under the air temperature put their a little hoose that goes to the regulator on the mfi unit on the nipple where normaly nothing is fixed
do this will work good? it only help more to be rich at boost ? don t need anymore to setup the fuel pressure ?

thank you rob

luxembourgrst

her is a pic of my engine Uploaded with ImageShack.com

Rob_DOHC

iTrader: (4)

No, read what I wrote again. Yes the vac line on the regulator seemed to work well enough for the short time it was there before I converted to efi.

Rob,

Rob_DOHC

iTrader: (4)

PS, nice engine bay but the picture doesn't help as its missing most of the mfi unit. But it sounds as if you know where everything is anyway.

Good luck, adjust things slowly and take it to a dyno after and get them to do a run and check for det.... I take it the dyno's near you use det cans?

Turbosystems

iTrader: (5)

Do not do this
Fitting a pipe to the inlet manifold from the pressure regulator has the total opposite affect on The bosh MFI it will richen at vacuum and lean off when on boost
The system runs a continuous stable fuel pressure, the fuel is metered into the engine by varying the pressure differential between the upper and lower chambers

luxembourgrst

sorry 10.5 over 15psi and 11.5 at 15psi

well ok i gonna instal this vacum pipe to help enrichement at full boost

at put 13.7 AFR on idle

Ben26

Intresting.

luxembourgrst

and if i put it on the crooss pipe over the cam cover and not on the manifold

Turbosystems

iTrader: (5)

If you need to alter the fueling you must alter the electromagnet fuel pressure actuator

luxembourgrst

yes but for this i need a tuner or a O2 lambda...


maybe i just can have my 200 bhp at 20 psi or 19 psi with my co screw to have 10.5 AFR on full boost ...
i will try

but know a vacum pipe to the regulator ? yes or no Rob VS turbosystem thanks

Turbosystems

iTrader: (5)

How can you set a car up with no equipment to measure fueling
may I suggest you leave the boost std until such time you have purchased some accurate fuel monitoring equipment or found a decent tuner

Ben26

Sell the car and buy a Push bike.

mgtkr1

unless you do some reading on mfi, buy a wideband and are fairly competent this will end in tears. an easier way would be to find someone who can tune your car safely. fuelling for a bar of boost is fairly easy, much over this is a gamble. have it set up by a competent tuner or be prepared to pay for a rebuild.

Stu @ M Developments

iTrader: (12)

As I said earlier, some cars weren't even safe on boost at 7 psi from the factory with only 130 bhp 27 years ago and needed the EMFPR tweaking by Ford at first service. DO NOT Turn it higher than standard unless you can monitor AFR with wideband.

The co screw ONLY adjusts the idle mixture. If you proceed to seek big boost the way you are doing now you DEFINATELY WILL destroy that engine.

luxembourgrst

ok well which wideband can i buy to do some fuel pressure setting..?

Ben26

I bought the innovate lm2 full kit . Works perfectly.
Just search fuel pressure gauge on ebay. A fluid filled one will b fine

luxembourgrst

and what depend the fuel pressure off? i need so mutch pressure that on full boost my afr is 10.5 (over 15psi)


if we turn a quarter on the black box (elec pressure) on the metering unit how mutch will it push up the pressure enough?

Stu @ M Developments

iTrader: (12)

Please do NOT plum a fuel pressure gauge into the injection lines on an RST guys. Just adjust the EMFPR a little at a time until your fuelling at full load right to the limiter is fine in 4th gear. There is NO OTHER WAY to do this job.

Ben26

Sorry didnt make my self clear. I put a fuel gauge in my efi between fuel filter and fuel rail.

Stu @ M Developments

iTrader: (12)

That won't do him any good on MFI mate.

Rogeyboy

iTrader: (2)

Luxembourg, You need to listen to these guys on here. Theres some very experienced people trying to guide you in this thread. Start over, re-read it all and listen to their advice.
One thing is for certain, you need to get yourself a wideband AFR gauge, i run the innovate unit, aem also do one. Check ebay and google.
One of these is essential if you plan to tune the car yourself! If not you need to spend some money on getting to a pro.
Until then i'd slacken the actuator rod right off, so you run minimal boost 4-7psi and even then dont push the engine too hard!

Ben26

^ best comment so far

luxembourgrst

it s again so expensive this wideband ...but yes you alll have reason o curse.... but first i want only try with this vacuumm hose (history) to the fuel regulator as Rob says he had this befoore he changed to EFi and it helps
i do this and i will check if at fulll boost (over 15 psi) i will have 10.5 on AFR if not i really have to toutch the fuel pressure with the black box and for this i also realy need a wideband o2 ......

Ben26

2 words- Good luck

JamesH

iTrader: (21)

Definitely some selective reading going on here

mgtkr1

don't do the vac/fuel reg trick unless you know what your doing. for the sake of an expensive engine rebuild a wideband setup is peanuts. you have 3 choices. have it set up properly. buy the equipment that allows you to moniter the fuelling and afr ect or 3. keep pissing around with it and blow it up. turbosystems and stu and countless others who are experienced have given you all the advice you need. if I were you id heed there warnings/opinions

scoooby slayer

iTrader: (4)

lol no wonder so many good engines get blown up, aem widebands are only Ł128 from usa.
if you cant afford or refuse to buy a wideband then leave the car standard its as simple as that, things go wrong sometimes through age/wear let alone messing with it and not knowing what the hell ur doing !
its honestly a recipe for disaster, either do lots of research and get some monitoring equipment or get it to a good reputable tuner who has experience with mfi rs turbos.

luxembourgrst

well ok i put this vacumm hose to the fuel regulator and put the AFR to 13.7

i checked my boost pressure and i am at 1.5 bar what i dont understand because my ecu chip only goes to 18 psi 1.24 bar the engine run good at full boost i have like 12 at AFR

know i put 12.7 AFR on idle have to try howmuch afr i have know at full boost

im looking forward for buying a wideband

Rob_DOHC

iTrader: (4)

I have no idea if your correct or not, TOTD did this to my car when I first had it set up, worked a treat. I still have (if I can find them) two dyno graphs of mine with the afr curve over laid before and after. After shows a clear leaning at vacuum and richening on boost.

Its a very easy thing to test and if it works as it did on mine! then happy days.

A few months later I threw the mfi in the bin anyway.

Rob,

Rob_DOHC

iTrader: (4)

Im so confused, Do you have a wide band lambda installed or not? I was under the impression that you DID. If you don't then you need to stop adjusting things until you buy one. I have been recommending things based on me thinking you HAD a wide band installed, I woulnd't have given any advice at all if I knew you didn't have one fitted.

Unless you are doing this setup at a local dyno?

Playing is learning in my eyes, you just have to be safe and play at low boost, otherwise (as every one has said) this will end in tears.


To clarify, this was not done by me but by another company several (5ish) years ago, the company has since closed so I can't check what they did, however he connected the vented FPR to the manifold in front of me so I know that is WAS done.


Rob,

Rob_DOHC

iTrader: (4)

Although, if your right that would mean the atmospheric side would let the regulator perform crude barometric correction which is kinda cool!. Im just looking through old pics now to see what was actually done to my car, perhaps I was being sold a load of BS? Seemed plausible enough at the time to to argue, especially with the graphs to back it up.

Rob,

James @ M Developments.

iTrader: (2)

I would also take the exhaust clamps off the boost hoses and throw the braided fuel injector lines in the bin if they have the usual internal diameter 2/3 the size of the oe lines as it will be lean on load with them fitted no matter what you do.

Ben26

He must have one if he knows what his AFR is

luxembourgrst

yes of curse i have my AFR innovate mtx installed

well look what STU motorsport devlopement says:
The most common thing I find
is that people have just tuned
their cars badly. On Bosch K I
see too much fuel pressure
caused via the shims, and on
KE I find people have gone
bananas on the electro
hydraulic fuel pressure actuator
to get more fuel for on-boost.
This is a bad way to tune and
the system will need a pro to
put it right again safely

What effectively happens when the
engine is running is this:
The fuel pressure is set in
this example, to 3.5 bar at
atmosphere. That’s with the signal
pipe disconnected. When we
connect the pipe, it acts on a
diaphragm and spring and affects
the fuel pressure with a ratio of 1:1.
This means that for every 1 psi of
difference the plenum has to
atmosphere, the fuel pressure will
be adjusted accordingly by 1 psi.
For example, if we have 1 bar of
pressure at the pipe (1 bar of turbo
boost), we will run our 3.5 bar plus 1
bar of additional pressure.
This has the effect of ensuring
the fuel pressure at the nozzle is
always exactly 3.5 bar above
whatever pressure is measured
within the inlet tract, so the fuel
fl ow is always constant and of a
known entity, unlike the fl ow we
had through the straw once we
equalised the pressure. Just think
what would have happened if we had applied 8 psi to the other end
of your straw... oops.
So, in a nutshell, we need to keep
the fuel pressure a set amount
above whatever pressure is seen in
the plenum at the injector pintle. If
we have 1-2 bar of vacuum in the
plenum, our regulator works the
other way and drops the pressure a
bar, too

this about the vacum PIPE Fuel
pressure
regulator:
Lean
conditions are not exclusively
created by the introduction of
additional oxygen, sometimes
they can be caused by a
reduction in fuel. When the
vehicle is mapped, a base fuel
pressure will be set on the fuel
pressure regulator. The small
nipple on the top of the regulator
is connected to the inlet manifold
and receives a pressure signal.
This allows the regulator to
increase the fuel pressure at
the same rate as boost pressure
enters the inlet manifold on
a turbocharged car and will
increase
in
approx half a bar
under acceleration
on an N/A car. If
this pressure
reference pipe
becomes
damaged or
detached
the fuel
pressure
will stay
static and
not rise when
accelerating,
or on turbo
engines when
boost pressure
enters the inlet
manifold. This will also result in a
dangerously lean condition

James @ M Developments.

iTrader: (2)

That does not relate to the fuel pressure reg on k E, the pressure reg should have no connection to the manifold for a pressure or vacuum reference on that system as Tony correctly mentioned earlier.

Rob_DOHC

iTrader: (4)

Thats what I was assuming, but every one above (mostly) seemed to think he didn't have one.

I think a lot of this is lost in translation tbh.

luxembourgrst

i have one for sure innovate mtx 12.7 at idle also on boost some times 12 somtimes 14 on boost but never lean as 22 that was before when i didn t put this vacumm line it realy helps

in normal driving no boost i have 12.7 -13.7

luxembourgrst

no i need biger fuel lines from the meetering unit to the injectors?

can i toutch the black box one quarter turnn clockwise only setting this with my AFR wideband ?

it better then the vacum pipe on the fuel regulator