Apologies if i've missed the boat guys.

Am swapping a 1.2 16v mk1 punto sporting lump into a Cinquecento i was given, have spoken to YcMing on Clubcento and he seems to think that the standard Cinquecento fuel pump is sufficient to run the multipoint injection used by the 16v lump, just wondered if anyone could verify this?

Sorry Ming not meaning to doubt you but saves two trips to the scrap yard.

Many Thanks

It's better to run the MPI pumps as they are regulated to 3 bar pressure. Not sure on the pressure for MPI injectors on a 16v but it would be better to use one of the newer pumps anyway.

Thanks

X

from what i've read the mpi injectors require a much higher pressure then the spi pump provides, so running mpi injectors with the mpi ecu etc.. will get you into trouble most likely.

in my old cinq spi when i put a punto 75 engine mpi in after a while my punto 75 fuel pump failed so i put in the original cento pump for a day until i got the new pump and with the standard cento pump the engine ran terribly, on heavy acceleration the engine would splutter causing the whole car to shake, so i wouldnt advise it

My 16v runs fine with the standard cinq pump.

Ming

Still doesnt really give much closure lol. Interesting if some have got it to run on cinq standard pump.

benwyl said:

Still doesnt really give much closure lol. Interesting if some have got it to run on cinq standard pump.

Click to expand...

yeah man, if you can get one cheap i would just fit it to be honest!

Really is a 30mins job!.

Ming

Without the particulars of the pumps, it's an impossible call. After all, the pump doesn't know it's got to produce 3 bar, only that it has to deliver so much gas.

all the welbro pumps are the same internally (other then the higher power ones have a higher power motor it seems (less windings on the motor))

what sets the spec pressure of the pump is they have an small hole in the plastic the end where the fuel is sucked in.

if you look down the hole there is a little metal disc pushed in there (some older ones have a grub screw)

this plate (or screw) holds a spring and ball under tension which makes up the over pressure relief.

so if you really needed to use the standard pump you could look at this

craigb244 said:

all the welbro pumps are the same internally (other then the higher power ones have a higher power motor it seems (less windings on the motor))

what sets the spec pressure of the pump is they have an small hole in the plastic the end where the fuel is sucked in.

if you look down the hole there is a little metal disc pushed in there (some older ones have a grub screw)

this plate (or screw) holds a spring and ball under tension which makes up the over pressure relief.

so if you really needed to use the standard pump you could look at this

Click to expand...

thats very intresting to no
so if you where to stiffen the spring up some how or stronger spring then the pump is fairly usable?
you could use a fuel pressure guage to set up the pump until you get the required pressure???

ive never done it but i know its doable (remember reading about it on a website with people in the same situation (fitting a modern engine with a high pressure fuel system when the old was low) and what i said was what people did/do


the valve is not a regulator... its a safety feature.

think of it this way... the original fuel system in the cento is just over 1 bar.
the mpi setup is 1.7-2bar (pressure changes depending on engine load)

the fuel system is designed for low pressure and so the fuel pump is deigned not to go much over this pressure (these pumps could easily double or triple the pressure if allowed) so if there was a blockage/folded pipe the pressure couple build till something goes pop.

i doubt the valves are that accurate. so all you really need to do is find an allen key about the same size as the hole and push it an a little bit.