65 replies to this topic

[nicksuth]

Anybody come across or fitted this or similar? MINI COOPER POWER BOOSTER KIT MPi, FUEL PRESSURE REGULATOR

http://nmdealer.mini...1/InvDetail.cfm

[perryman1001]

theres some mixed feelings about those so i believe, that they only really work on heavily tuned engines. Ive got one waiting to go on my mpi but just havent had chance to fit it. Im also having similar fuel problems to you and am going to investigate into it over xmas so will try most things you have.

oh yeah and also, when i acquired my burlen throttle body, on the instructions it said about switching the ignition onto number II pressing the accelerator down 5 times slowly then turning the ignition off and leaving it 15 seconds before restarting it which supposedly resets the fuel/air mixture readings on the ECU, not sure how true this is though??

[sirweste]

I've heard mixed things about the pressure regulators. I know MLMotorsport of Kent have found that when they remove the "uprated" ones fitted by JCG the car ran better without it. MPi's already run a little rich i have been told on a few occasions, so increasing the pressure (if thtas true) won't be of benifit.

My next step would be a fuel rail pressure reading.

[mini 4o]

hi all
so how did it go with the fuel pressure test?
buying any after market items in my mind is a waste of money / time until you know your mini is running well.


next pop along to a garage somewhere that can fit an in-line pressure gauge to check the fuel pressure is constant. then if you must change the fuel reg
good luck
john

[nicksuth]

Can anyone confirm what the fuel pressure (at the fuel rail) should be? I have been told 4 bar (56 psi) by one person and read somewhere that is should be 2.5 bar (35 psi), I do know it's different to the SPi which only runs at bar (14 psi).

[KLAS]

you should see around 2,5 bar with closed throttle and 3 bar at wide open throttle

Edited by KLAS, 30 November 2008 - 09:50 AM.

[mini 4o]

[hi all
around 2.7 as soon as the regulator lifts, leave the gauge for at least 10min to settle with the ign on .
no need to start the engine, just watch to gauge if it fluctuates then look for a petrol leak, noisy pump, or faulty regulator
best of luck
john (in corfu)

[Sprocket]

[hi all
around 2.7 as soon as the regulator lifts, leave the gauge for at least 10min to settle with the ign on .
no need to start the engine, just watch to gauge if it fluctuates then look for a petrol leak, noisy pump, or faulty regulator
best of luck
john (in corfu)

If the engine doesnt run, the pump only runs for 2-3 seconds.

if you do manage to get the fuel pump running without the engine, fuel pressure should be 3bar. If the engine is running and idling, fuel pressure will be around 2.7bar. The differential pressure remains the same at 3bar.

[nicksuth]

Thanks for all the pointers guys.

Latest update is I changed the throttle sensor (TP) and no change, went to change the MAP sensor and found it loose (aha! I thought, maybe this is the culprit all the time?), took it off, cleaned faces, refitted, no change (bugger) so changed for new unit, no change (double bugger). I had also bought a link pipe to take the CAT out of the equation but have yet to fit it (I can't really see it being the culprit but hey, what the hell, in for a penny in for lots of pounds....!).

Spoke with John (Guessworks) about it tonight at RCMOC meeting and he wonders if it might be the manifold cracked again (been welded up once) at the weld joining the two outer pipes as it's just above the lambda sensor and this could be sending it false information (i.e. too much O2)? The LCB is getting a bit "scabbie" now as it's been on/off like a bloody YoYo so bit another bullet and ordered replacement (that's just about all my christmas presents taken care of now = nothing to open on the day!!!)

I'll post updates when I get it fitted.

PS - Any further advice form you "Injection Gurus" always welcome.

PPS - posted seperate topic regarding throttle body and whether it's worh going for the 52mm one, wadyarekon??

[Deathrow]

I'm sad to see you've not found the answer yet as we're having the same issue with our MPi, it's been to a garage and he gave it us back without charging us because he couldn't work out the problem.

However, we are sure our CAT has bit the dust so we're going to have a decat pipe fitted soon, if the problem remains it's going to an auto electrician.

After reading what Southy said about manifold temps, I'm going to take my temp gauge out with me when I nedt take the car for a drive, I'll measure the manifold temp as soon as I turn the engine off after a run, if it reads high then we know the CAT is doing some bad.

Do you find yours gives a "pop", seemingly through the filter?

Ours runs like a dream when it's cold, power through and through, soon as it's warm, it struggles to accelerate under load.

[nicksuth]

Posting at 05:07 !!! Can't you sleep ????

Do you find yours gives a "pop", seemingly through the filter?

No, no signs of of a "pop" through the filter but it does have a bit of a "pop" on deceleration (throttle closed) through the exhaust but I think that's normal?

Ours runs like a dream when it's cold, power through and through, soon as it's warm, it struggles to accelerate under load.

I wouldn't say it runs like a dream but it does run better when cold but I guess that's due to the ECU applying "cold" condition running settings?


Unfortuinatley, MiniSport have let me down on delivery of the new alloy throttle body and I'm reluctant to start the strip down until it's here, so all the other jobs (LCB, DeCat, Injectors etc.) will have to wait!!!!

I'll keep you posted on progress.

[chudley]

Help!!!!

You may have read my previous threads about my MPi and it's constant poor running?

I recently changed the head gasket having identified an oil leak (with the help of John Guess) as coming from the corner of the head. This indeed turned out to be the case (back right hand side corner) and also into No.3 cylinder (from n/s end) which was a bit wet/oily/sooty (although the plugs never really indicated that) I also took the opportunity to change the Lambda sensor having had the car to Icklemini for plugging into his reader and identifying it as a possible problem (readings at tickover jumped about between 1 and 4 mV and on a run dropped an maintained 0mV, we also ran it disconnected which seemed to make the engine run better?).
Well after all this along with new plugs and leads (new set of iridium BKR7EIX's and today BPR6E's), new Air Temperature sensor and Camshaft sensor it still has the spluttering under steady acceleration!!! When I say "steady", it runs okay if very light and very heavy throttle used but anything in between casues it to hesitate/splutter as if it's getting starved of fuel?
It becomes worse once the engine is up to running temperature but ticks over no problem at around 850/900 rpm, saying that when ever you rev the engine it drops to around 1500 for about 2 or 3 seconds before it returns to normal 850/900.
Within the last 1500 miles (most of which was before I had it) it's had a new coil pack, wiring from ECU to coil pack, ECU removed and checked over, direct feed from battery through extra relay fitted to fuel pump (due to low volts identified [11.2v]) and injectors cleaned and new o rings.

Looking at a previous service (Dyno-Tune) report sypmtom is as follows..............."As engine warmns up, fueling leans off until hesitation occurs at all engine speeds, emmission measurements variable" The previous owner then spent over £850 on having it fixed from which the only change that improved things was the fuel pump direct feed through relay!!!

I am fast running out of money to replace anything else........HEEEELLLLLPPPP

PS - Southam Mini & Metro Centre had a quick look at it on their diagnostics machine and thought it was a fuel/air problem and to check for leaks - been all over it to no avail. They also suggested fitting a variable fuel regulator thinking it may be fuel pressure related? (is it 2 bar they run at?)

PPS - It has a Race Icon Chip fitted but have tried it with this linked out (thanks to Icklemini) and it made no difference at all?

i been having same problem on a spi cooper and still have , i have changed coolent sensor, lambda sensor, new exhaust lcb, head to larger valved, head gasket, rockers to 1.5 , plugs leads, fuel filter and still does the same i was slowly upgrading it anyway but tried each thing at a time to see if i could find the fault but still have not so if you do please let me know .

[nicksuth]

Take the cat off and look at it through the holes, it should have a uniform honeycomb look about it. It should be an off white colour and you should be able to see daylight through it.

When was the fuel filter replaced, if it hasnt, change it. Otherwise the fuel regulator is a strong possability. The way to check that is by fitting a gauge.

Only other thing to consider is have the injectors ultrasonicaly cleaned, the fuel addatives that recon they clean the injectors, dont do much.

CAT now removed and I've taken a photo of inlet end and outlet end if you would like to comment? I can't see daylight through it but it doesn't seem to look too bad (off whiteish with a few blocked pores!!!)

Oh, and you probably guessed that 2 of the 4 studs sheared off !!!

[nicksuth]

Latest update and "I think it's cured"???? Will give it a run out tomorrow to make sure

So what did I do....................

New LCB Manifold, Link Pipe, DeCat Pipe
Made sure all joints were correctly engaged, sealed and nipped up (oooh it don't half sound nice with no CAT fitted but I guess it will have to be replaced and go back at some point, boooh!!!!)
Fitted Power Boost Valve with Pressure Gauge
O Rings had gone in original Regulator at end of Fuel Rail (posible cause?)
Pressure Gauge read 2 bar after installation (ignition on only), 2.4 bar when engine started and running at tick-over (once engine warm) and 3 bar when throttle "blipped" - any comments from the MPi experts?
Fitted Reconditioned Injectors, O Rings etc.
Bought set of used injectors from Rover 220 Turbo (same as MPI - MJY100460) and had them ultrasonically cleaned, reconditioned, new filters and full pattern/static flow test (now 417 & 420 cc/min @ 3 bar and 16.7 ohms) by www.injectortune.co.uk
Thorough Clean and Lubricate of all Throttle Parts
This should have said "Fitted new 52mm Alloy Throttle Body" but due to MiniSport not delivering it yet, the old plastic 48mm one went back.
I did notice that the butterfly did not go fully back to it's seat when closing off until I cleaned it up and adjusted the throttle cable, this may have been the cause of the idle speed sitting at 1500 rpm for a few seconds before dropping back to normal (850/900 rpm)?
One question here? - Will the ECU learn this new position from the TPS now?

I will still fit the new Throttle Body when it arrives to make use of the Power Boost Valve (fuel pressure) improvement - or that's what I'm told???

Report on that in near future.

Edited by nicksuth, 28 December 2008 - 09:14 PM.

[nicksuth]

Fitted Power Boost Valve with Pressure Gauge
O Rings had gone in original Regulator at end of Fuel Rail (posible cause?)
Pressure Gauge read 2 bar after installation (ignition on only), 2.4 bar when engine started and running at tick-over (once engine warm) and 3 bar when throttle "blipped" - any comments from the MPi experts?

Do you think I may have a problem with the fuel pump, i.e. not generating enough pressure?

I see from previous posts that fuel pressure should be 3 bar (mine currently 2 bar) with ignition on and engine not started then 2.7 bar (mine 2.4 bar) when on tick over.

I have the pressure gauge connected to the regulator measurung pressure in the return line (as photo below). Should I maybe have a pressure gauge in the fuel feed line (before the fuel rail)?

[attachment=76911:pbvgag.jpg]

Bottom connector goes to fuel return line (back to fuel tank), side connector is from fuel rail and is the new return line and top connector is the vacuum line back to the manifold (as picture below [not Mini but same principle])

[attachment=76912:pbvfit.jpg]