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Malpassi fpr noises


bowtieboy56

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Hi all, I am having issues with the malpassi pressure regulator in my duratec powered cortina. The thing is noisy as, its screaming and the gauge I have screwed into it is bouncing all over the show 

I can adjust the pressure up to say 40 psi and its quiet for a few minutes then it screams again, I then can screw it back to say 30 psi and same thing, quiet for a few minutes and screams again.

The unit is brand new from palm side and I have asked the guys there about it and they emailed malpassi who came back with..... our regulators dont make noise, you must have installed it wrong !!

Just  really wanting to know if anyone has had the same issue with them and is there a better brand out there to use?

Its feed by a in tank pump simular to a holden unit and through a jenvey itb system 

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Do you have a vacuum reference on it currently, and does this happen both when engine is on and off? 

Like can you leave pump running while engine is off?

If you're taking a vac signal from a single runner from ITB it can have pretty big pulsations in the vacuum signal which might be why the gauge jumps around.

Definitely got a fresh new fuel filter, and you know that the pump is definitely good? 

If you've ruled out all of the peripheral stuff I'd take it back / ask for a swap. 
 

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hi Roman , not using a vacuum reference( just have that port open to air) and the filter ( filter is before the fuel rail too) is new along with the pump in the tank, when you adjust the reg it behaves, but not for long, i have even removed the fuel gauge on the regulator, plugged the hole and tried that just in case it was that  

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Sounds faulty to me. Especially if the presure is jumping around. Almost sounds as though there is something sticking inside and it has to build up more than the preset pressure before it bypasses.  Shouldn't matter if vac line is on or off.

I ran one the same back in the day. Had to keep an eye on the base fuel pressure as would drop over time. Others had same problem.  I try to use factory regs when possible now.

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thanks Kpr, so since i am not running stock efi system (am running jenevy itbs ) whats a good brand of reg to use?

 i am going pull this one and pull it apart to see whats going on and chances are i will find zip, so i will most likely biff it

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I know nothing about that regulator, but thinking out loud...

For a fluid to make noise you need cavitation/turbulence, that suggests high flow, I assume the engine isn't sucking excessive amounts? what kind of flow goes back to the tank? Can you try throttling the flow from the pump to slow the feed to the reg/ is it sized too big?

Also the feed does a 90deg right as it enters the regulator, can you remove that and see if it helps?

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Is it possible to apply vacuum to that port and see what changes ? I have not used malpassi efi regs but all factory and adjustable aftermarket efi regs I have used do have a vacuum feed plumbed in . another thought , is it plumbed on fuel return side of rail ? good luck , seems an odd problem 

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I had a malpassi in my rx3 and it used to make a strange noise.

Anyways it only happened when the car hadn’t been used for a long period of time then after driving around a bit it would be fine.

I ended up replacing it for a turbo smart one.

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good point nickj, i think its turbulence too, but i also dont know how much volume the malpassi can take and my fuel pump came form tanks inc in the states as a in tank kit with out any specs on volume.

 i could try fitting a valve in the line but not sure how to monitor it, as you cant gauge the flow rate.

 yes tim13 its plumbed on the outlet side of the fuel rail and that bottom outlet goes back to the fuel tank in a 3/8 aluminum line

 i haven't tried hooking a vacuum line to the top.

the trick here is that it does it either way with engine running and off, so its got to be flow related, maybe there is sparp edges in the regulator that are causing it, wont know till i pull it apart.

 kind of expected this to be a good reg as Palm side use these on their rally cars

 

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