So iv'e performed an engine swap, from a Mk6 fiesta to a MK6.5 fiesta (more below)

Got new engine in and attempting to start it and she has a real tough time starting up.

Nine times out of ten it will just die. If i leave it a while it will fire up.

When it eventually does idle its hunting and will conk out.

If i drop the clutch when it does run it will idle around 1500 RPM. When it does this it idles fine, no miss or anything but the revs still hunt.

When its attempting to fire the plugs are wet so i assume its getting fuel.

Took HT leads on and hooked up to a spar plug, jump lead from plug to battery negative and it sparks.

Swapped camshaft sensor, swapped crankshaft sensor, swapped spedo sensor. Still giving issue.

Checked continuity between engine and chassis and its earthed.

MK6 - MK6.5
I have a donor car, was scrap, that the engine came from. It has been stood for nearly a year. However its a MK6.5, face lift. I didn't realise the quantity of changes between the face lift and non face lift.

I swapped the entire interior and loom so i can have elecy windows etc. All the interior electrics work fine. And when the engine does eventually run it runs, all be it with poor idle.

So in a nutshell i checked everything i can think of and swapped everything else and a little very stumped.

 

Any help would be greatly appreciated. Only other thing i can think of is fuel pumps are different. Its the MK6.5 running with the MK6 fuel pump. However I'd be very supprised if they run a different pressures and really wan't to avoid having to drop tank.

Thanks.

Have you cleaned the throttle body? I have a 1.6 duratec that wouldn't idle until I'd taken off the throttle body and properly cleaned all around the underside of the butterfly and adjacent body. There should be a tiny gap between the butterfly and the body that allows air through for idle; make sure that is clear all the way round. use carb cleaner and a brush.

Thanks, no i hadn't. I do remember when inspecting it however there was no gap between the butterfly and body walls.

Long story short the car is now in the car-park in the sky.

It was a hell of an experience (never done an engine swap on my own) so glad i did it. Still a shame it ended up the way it did, but meh it was fun.