my mates mfi s1 rs turbo wont start unless you press the paddle on the air flow meter about a 1-2mm down. When its started it will back fire and not idle untill engine is warm. we have disconected the cold start valve and no luck. alll plugs leads ect have been changed for motorcraft items. the fuel pump relay keeps cutting in and out constantly or if i tap it ignition key it will stop. Could all this be the fuel pump or relay.

it seems to be getting plenty of fuel.

 

try replacing the fuel pump relay and if no luck try replacing the cold start valve atleast you will be eliminating things hope this helps

 

it sounds like the fuel pump/distributer(the silver thing with the red fuel pipes coming out of it by the air filter) may have some crap in it,try stripping it down and giving it a good clean.
sorry if i'm telling you to suck eggs fella

 

Its an air leak!!!!

 

i have been over all the pipes about 5 times with no luck what makes you think its a air leek. it runs fine when its warm wouldn't it keep cutting out? i have changed the fuel distributer and its still the same.

 

because pushing the flap down is giving it extra fuelling, if it has an air leak the flap won't move enough and therefore not enough fuel.

It could also be that the mixture is set very lean.........

And by the way air leaks can develop in about a million places on a MFI car, not just boost hoses.

 

tbh i think its over fueling as the plugs are wet when taken out.

 

well pushing the flap down would only make the problem worse then?!

 

it starts tho could it be to little fuel pressure or not enough air?

 

if it was not enough air then it would be an air leak as i say above.

But either way, too little fuel pressure or not enough air, that wouldnt result in wet plugs?!

 

true

 

if you've been trying to start it forever and a day then the plugs could well be wet.

But if you have to push the flap that shows there is an air leak and/or not enough fuel entering the cylinders.