sponners

What can effect the cold start on the duratec se?

The car has an intermittent problem where occasionaly on cold mornings the car struggles to start (as if the choke isn't coming on). It fires but you have to try and keep revving it otherwise it will stall, but once the engine has warmed up a little it's fine.

The car runs great otherwise.

Is there an icv on this engine? or is it part of the electronic throttle body?

Any suggestions?

mattxr3i

Coolant sensor maybe duff

martysmartie

iTrader: (1)

No FI car has a choke, the fast idle is achieved by the ISCV, they can get "gummed" up, so it may be worth removing and cleaning it, on your engine it's to the left of the plastic inlet manifold (as looking at the car from the front)

It has an electrical connector and 2 bolts, just be aware there is a gasket (I think) if so you will need a replacement as this will break when you remove it.

If yours has an electronic T/B you almost certainly won't have the ISCV, instead, as you say it's part of the 'fly by wire' throttle.

Martin

sponners

Cheers guys, I had a look for the idle control valve on the car earlier and couldn't see it and also noticed that it has a electronic TB.

Is the coolet temp sensor used for the ecu the same sensor as is used for the temp display on the dash? because that seems to work fine.

Also noticed the car is mafless so just trying to figure out what sensors the ecu is reading for the cold start,
IAT?
Coolent temp?

I did notice when it fires from cold but struggles to run that it does smell rich from the exhaust so that got me thinking it is a ICV issue not raising the revs but as it seems that idle control is part of the TB it has me scratching my head.

zetec-Sam

iTrader: (2)

Check the breather pipe from the block to the inlet manifold, they are prone to splitting, and can cause a number of problems, including the one you've mentioned.

martysmartie

iTrader: (1)

Electronic TB won't as it can use it for air compensation instead. The engine has a "TMAP", it's inside the inlet manifold, so you can't see it, as a point of interest phase 1 engines had a MAF.

Check the mentioned breather pipe next.

Martin

sponners

Cheers,

I'll get that breather checked next. Can anyone explain to me though why a leak post throttle body cause this? Surely a leak there under vacuum will cause the revs to rise? and why it would only effect it when cold?

What is the 'TMAP'? is it a inlet temp and map sensor in one?


Thanks.

zetec-Sam

iTrader: (2)

Because a leak in the inlet manifold is introducing un-metered air into the engine, so air the MAF has not detected, so the ECU does not know about. When my breather was split, my engine hunted massively at idle when cold, almost to the point of stalling, but was pretty much OK when warm. The guy in Ford even said they're surprised how many problems a little pipe can cause!

Edit-Ignore what I said about a MAF if it hasn't got one as Marty said.