2004 ford fiesta 1.25 - Fiesta Stalling - gtomgee

Hi. When i rev up my fiesta the revs then dip down to 500 rpm and almost cuts out. when driving along, coming to a stop or depressing the clutch the engine will drop to 500 rpm and cut out. So far i have replaced the throttle body with 2 different units but to no avail. My initial thought was that the iacv maybe faulty which I know is governed by the throttle body in this model.

Car holds good vacuum. When the vacuum line is removed from fuel pressure regulator on the injector rail, the car runs spot on. I have tried replacing this also to no avail.

Any other suggestions wouyld be greatly appreciated. Thanks!

2004 ford fiesta 1.25 - Fiesta Stalling - elekie&a/c doctor

Removing the vac pipe to the fuel pressure reg increases the air being drawn into the engine via the open pipe,so will increase the idle speed.Nothing to do with fuel pressure.Have you tried re-setting base idle to throttle body after fitting.?Disconnect battery for 10 mins to allow the ecu to relearn.There is no iacv on these,idle control is adjusted via the throttle control body.

2004 ford fiesta 1.25 - Fiesta Stalling - Railroad.

Check the vacuum pipes underneath the inlet manifold as they're well known to split. Disconnecting the vacuum pipe from the fuel pressure regulator will mean fuel pressure will be at maximum all the time, but you will of course have a vacuum leak at the same time. If the vacuum pipes are split, and you correct it, the engine idle will take a while to stabilise but eventually it should.