tim windmill
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| posted on 2/9/07 at 07:43 AM |
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fuel pump problems
2.0l blacktop with standard injectors and fuel rail and regulator, running a vauxhall calibra in line fuel pump. getting 5.5 bar pressure at the fuel
rail and the pump is still continually running and pumping back to the tank. am i thinking right that the fuel pump should stop when it gets up to
pressure with engine not running. using the standard regulator i think should operate at 2.5 - 3 bar does it sound like my fuel pump is knackered? I
cannot get the engine to run i assume its down to this fueling problem, any help appreciated.
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mark-wiring
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| posted on 2/9/07 at 08:10 AM |
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The fuel pump will run constant to keep the supply of fuel in the rail at the right pressure its the job of the reg to make sure that happens
correctly.
Poss answers to your problems;
Fuel pump is too high in volume for the reg to actually get rid of the excess fuel.
The reg is nackered and need to be replaced (very rare this one).
Did you match spec's of a std mondeo pump to the calibra one?
Can you lay your hands on a sierra one? (close enough as make no diff to the mondeo one)
Have you got the fuel circuit running correctly? I know its a stupid question but you never know. It should run Tank-Pump-Filter-Rail-Tank. I'm
sure you get the idea.
Hope this helps
http://www.v10viento.co.uk
Have to recommend
http://www.extraefi.co.uk/
For all Megasquirt needs
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tim windmill
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| posted on 2/9/07 at 08:22 AM |
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mark thanks for the reply, ive got fuel lines tank - pump - rail - regulator - tank,
i know the calibra runs at a much higher flow rate than the mondeo one but i thought that when it got back pressure from the regulator it should stop
and maintain the fuel pressure at that level until the engine runs and the pump would restart?
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chriscook
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| posted on 2/9/07 at 09:01 AM |
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If your reg is not attached directly to the fuel rail - have you got it plumbed in the right way round?
Fuel should continually circulate but the reg should maintain the pressure to whatever its set to.
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NeilP
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| posted on 2/9/07 at 09:04 AM |
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I had too high a pressure regulator in my rail and I found that I was getting a problem at high loading as the injectors weren't up to the
higher pressure and so it was going way to rich and then the ECU advancing way to far.
Starting was never a problem (as rich is good).
Might be something else - Follow the AA man's mantra of air, fuel, spark, timing?...
HTH
If you pay peanuts...
Mentale, yar? Yar, mentale!
Drive it like you stole it!
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MkIndy7
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| posted on 2/9/07 at 09:24 AM |
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My XE fuel pump runs all the time in the Nova with all the standard ECU and setup, even with just the Ignition on, so I wouldn't worry about
it.
Not sure if you've copied the complete setup but in the Vauxhalls there is a "fuel dampener" or words to that effect just after the
fuel pump, its shaped a bit like a pressure regulator. I think its there to keep a steady pressure in the fuel line rather than the pump giving big
pulses.
I'm not sure there is any facility for turning the fuel pump on and off at pressure, unless its internal to the pump, which I doubt as there
fairly compact and not an in-tanp pump where they could have the regulator in there. There is no connection with the fuel line anywhere to tell the
ECU when its upto pressure to turn it on and off.
I hope it doesn't cause any problems cos we've got a gread big Mercedes inline pump on the Indy!
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bigrich
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| posted on 2/9/07 at 10:12 AM |
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the pump runs constantly with the engine running in the car and the regulator dumps back excess pressure/fuel to the tank. heck the return side of
your system for flow,restriction in any pipes due to kinking etc.
although rare regs do fail usually increaseing fuel pressure up to max pump output which can be as high as 8 bar.
just a thought is the fuel feed and return on the right way round ie feed into the rail the return back from the regulator, as i'm sure this has
caught out a few before.
Rich
.JPG)
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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tim windmill
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| posted on 2/9/07 at 10:17 AM |
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regulator is attatched to end of fuel rail . pressure is in the fuel rail and nothing after , i have now throttled down the pump and have got 3 bar of
pressure at the fuel rail just for a short term fix but still cannot get it to run with the megasquirt ,good spark on all cylinders, fuel pressure,
10 deg advance, 400+rpm,
injectors get prime pulse as i can hear them click, sounds like they are opening on cranking but still wont go cannot even get a back fire. i am using
standard throttle body on a griffin manifold all dials appear to read ok on laptop and everthing was ok on stim.tried several base maps but still no
joy , help please
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bigrich
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| posted on 2/9/07 at 10:27 AM |
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have you tried cranking it over then squirting a bit of wd40/carb cleaner in to the intake to see if the engine tries to fire up on this, if it does
then i would go back to the fuel side of things. dont suppose you have a noid light to check the injector pulse under cranking .
just a quick question where are you measureing the fuel pressure is it in the feed line to the rail or actually on the rail itself?
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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tim windmill
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| posted on 2/9/07 at 10:31 AM |
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after several attempts at starting removed plugs and they appear to be dry so it looks like that no fuel is getting into the chamber, listened to the
injectors with a screwwdriver against my ear whilst cranking and i can hear them clicking so why is there no fuel , checked fuel pressure whilst
cranking 3 bar constant
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bigrich
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| posted on 2/9/07 at 10:37 AM |
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if you remove the return line from the rail and pipe it into a milk bottle or similar then crank it does fuel go from the rail to th bottle if so is
probably injector related ie blocked or stuckif not then i would check the rail/regulator and how its piped up
Rich
A pint for the gent and a white wine/fruit based drink for the lady. Those are the rules
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graememk
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| posted on 2/9/07 at 10:39 AM |
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i run mine at 35 psi if that helps
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BenB
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| posted on 2/9/07 at 10:39 AM |
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If you get some Easystart and squirt it down the throttle body neck if the engine starts it's a fuelling problem.
5.5Bar is way too high. How have you throttled back the pump?
If you've got sparks, fuel and compression it should run even if it runs dog rough in the process.
Strange.....
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MkIndy7
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| posted on 2/9/07 at 11:02 AM |
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Check for conflicting settings in the Megasquirt and turn EVERYTHING un-nessacery off.
We switched the Staged injection setting on ours (because we wanted it).. and it just would not fire, was as if the battery was flat, after reading
just about everywhere I found 1 page by the people that write the Megasquirt-extra code that said you could NOT run staged injection with alternate
injector fireing, although it never mentioned that anywhere in the mega tune manual!.
Can you hear or see any fuel being returned to the tank? to prove the regulator is working?
Have you tried fireing the injectors out of the car? some of ours were blocked
Maybe try 2 priming pulses?, and is the type of injector set correctly the High/Low impedance?
[Edited on 2/9/07 by MkIndy7]
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tim windmill
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| posted on 2/9/07 at 11:53 AM |
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going to try the wd40 if still no joy i will remove the fuel rail and injectors and fire them out of the car , throttled down the pump by putting a
jubilee clip on the fuel pump delivery hose before it gates to the regulatr so that it cannot deliver the same amount of fuel , i know this is no good
for the pump as it is putting under extra load but it waqs just a short term solution to get the pressure down to 3 bar
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MkIndy7
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| posted on 2/9/07 at 11:59 AM |
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quote:
Originally posted by tim windmill
throttled down the pump by putting a jubilee clip on the fuel pump delivery hose before it gates to the regulatr so that it cannot deliver the same
amount of fuel , i know this is no good for the pump as it is putting under extra load but it waqs just a short term solution to get the pressure down
to 3 bar
Not sure on your description there, but the Pressure regulator is on the opposite end of the fuel rail to the supply isin't it?
Where is the Jubilee clip?
A: on the low pressure inlet to the pump
B: on the High pressure outlet of the pump
C: on the return line to the tank
P.s replies might be slow the MotoGP's on lol 
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tim windmill
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| posted on 2/9/07 at 12:03 PM |
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on the outlet high pressure side of the pump before it gets to the fuel rail, still allows enough fule to flow to get 3 bar at the rail
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tim windmill
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| posted on 2/9/07 at 12:03 PM |
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on the outlet high pressure side of the pump before it gets to the fuel rail, still allows enough fule to flow to get 3 bar at the rail
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martyn_16v
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| posted on 2/9/07 at 01:16 PM |
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Something is off if the pump is running all of the time with the engine not turning over, MS will only run the pump while it's seeing an rpm
input, or for a short priming pulse when it's initially powered on (assuming of course that the fuel pump is powered via a relay controlled by
the MS fuel pump output).
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tim windmill
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| posted on 2/9/07 at 03:35 PM |
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thats what i thought re the pump, had the fuel rail off checked the injectors they are spraying ok but still wont start. Tried wd40 still wont run,
checked plugs and each are sparking. so points me back to the megasquirt and timing
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MkIndy7
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| posted on 2/9/07 at 03:50 PM |
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Is the fuel pump running constantly or pulsing on and off?
If its pulsing the Megasquirt does that when there's a big conflict/fault in the settings.
How do the guages in Megatune etc read?
Does the MAP signal and RPM look ok when turning it over?.
I've just thought of a problem we had (and you asked about it earlier in the week), after we ran EasyTherm the car wouldn't start... we
had to re-load a previous saved .msq set of settings. I think it had altered some of the Spark and toothed wheel settings and also coilpack/spark
dwell etc.
Might tie up with the fact that the plugs are sparking etc but maybe not at the correct time.
[Edited on 2/9/07 by MkIndy7]
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tim windmill
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| posted on 2/9/07 at 06:33 PM |
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all dials read ok, fuel pump is Not pulsing, good rpm, spark on all 4 cylinders, fuel pressure etc. ive got all the right ingredients but still wont
fire. cannot even get it to cough pop bang anything,tried loading several different maps and settings and still no joy, i am getting well hacked off
now!
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MkIndy7
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| posted on 2/9/07 at 06:41 PM |
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Has the engine run before or been dismantled?
Maybe it could be mechanical then, if you said the plugs were dry in a pervious post and everything else is in place, fuel and sparks etc.
I don't suppose the Cam timing could be 180 Degrees out if its been apart?
Hydraulic tappets that aren't opening due to low oil pressure maybe?
Anything like that, which could prevent the cylinders filling.
It does sound strange not to get and kind or responce, no back fires or coughs back up the inlet.
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Fatboy Dave
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| posted on 2/9/07 at 06:42 PM |
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Have you got the trigger wheel set up correctly? It's caught me out a few times when I've left it at 0 degrees and I've tried to
start an engine...
Dave
Stop the planet, I want to get off
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