fuel pressure dropping
Turbo Mini Forums

been trying to get my new engine going for ages. ive been having a problem with it slowing down (but doesnt seem to lose ALL power) when the revs build up and turbo begins to spin up.

ive checked every hose etc to double check everthings connected up right but no joy.

thought i'd check the fuel pressure this afternoon (had the great idea of connecting the boost gauge into the fuel line so i can see the pressure inside the car! it'l probly nacker it but ive got a spare!)

the pressure is about 4psi at idle but it drops off when the revs build up untill it is basicaly at 0 when the turbo should kick in.

ive tried swapping the fuel pump and the fuel pressure regulator but it doesnt seem to make any difference. i even tried swapping the feed and return hoses round as my return was smaller than the feed.

i'm completely stumped as to where to go from here.
any suggestions what to try next would be greatly appreciated!

cheers.

is your pump an fuel reg all turbo stuff? is your fuel reg plummed in right and i think your return pipe should be the same as your feed 8mm minimum. is your return in the tank in the right place and big enough and have you got the right gasket on your plenum to carb if you use a non-turbo gasket i think the holes are in the wrong place or summot hope you sort it soon

no longer a series, but still 1.3 turbo.

What size feed and return are you using ?
Is it the correct "rising rate" regulator ?

Phil.

WWW.TURBO-MINI.COM

Does sound like your regulator is plumbed in wrong... Have you checked it against the pics in the 'how to' section?

If this is ok, there is very little that can be giving the symptoms you describe (the fuel pressure not rising).

First thing to do is check the pipe that goes from the plenum to the top of the regulator. Remove it at the plenum end, and suck on it. If you are generating a vacuum, it is ok. If not, then it is either the pipe or the regulator that is goosed.

Next thing is to remove the plenum and check that the brass restrictor ring is still in place. This must never be modified or removed.

I'm strugling to think of anything else at the mo... check them, and report back

ive checked and double checked the connections coz that was my thinking too but i'll check again just to be sure!

i've tryed it with a metro turbo pump and regulator and also with a renault 5 turbo pump and regulator that i have lying around and different combinations of the two but it doesnt seem to make any difference.

i will check everything mentioned again hopefully i'll spot something, although it will have to be tomorow as i'm off to mini 45 today!

cheers guys.

is the renault 5 reg compatable?

no longer a series, but still 1.3 turbo.

My mate has used a Renault 5 Turbo regulator for a few years now with no probs.

Phil.

WWW.TURBO-MINI.COM

Sussed out the problem!

i managed to crush the air intake hose when i put the engine back in. the obstuction in air flow meant that as the revs went up there was vacuum created in the plenum chamber and so the fuel pressure regulator was dropping the fuel pressure instead of increasing it!

i know its quite common to crush the hose but i never thought it would have that affect!

i'll have to get myself one of those 'uncrushable' hoses this time to make sure it doesnt happen again.

I'm just happy i've finally got it sorted!

cheers, Ian.