Ford Fusion 1.2 petrol wont stay running when cold
Discussion
Friend has a 1.2 IIRC 2006 Ford Fusion petrol.
Recently developed a problem in which when starting cold, it will stall unless you hold the gas pedal down to keep the revs high. Completely goes away when the engine is warm and runs fine, no error codes. Even on some cold days it starts and idles fine, but usually not when cold.
Checked for vacuum leaks, no sign, airbox/filter is good, intake is clean, butterfly is clean, sparkplugs are fine. My next theory is the idle sensor? I dont think it even has a MAF sensor else id try that.
Recently developed a problem in which when starting cold, it will stall unless you hold the gas pedal down to keep the revs high. Completely goes away when the engine is warm and runs fine, no error codes. Even on some cold days it starts and idles fine, but usually not when cold.
Checked for vacuum leaks, no sign, airbox/filter is good, intake is clean, butterfly is clean, sparkplugs are fine. My next theory is the idle sensor? I dont think it even has a MAF sensor else id try that.
M_A_S said:
How did you check for vacuum leaks?
Painted soapy water and looked for bubbles, didnt find any. So sprayed liberal amounts of WD40 around joins and hoses listening out for a change in idle revs but didnt hear any. Ill get her the OBD reader that will rule out the coolant temp sensor pretty quickly
EazyDuz said:
Painted soapy water and looked for bubbles, didnt find any.
I hope you realise the intake manifold is below atmospheric pressure. Where did you think the bubbles would be coming from? 
EazyDuz said:
So sprayed liberal amounts of WD40 around joins and hoses listening out for a change in idle revs but didnt hear any.
You do stand a chance with that, but carb cleaner or cold start spray are likely to work better.After some internet research ive found 2 of the most likely culprits:
1. Glitch in the ECU software. Apparently a few have had cold start issues then taken it to Ford who updated the software and has been fine since. Alternatively dc battery for half an hour, let ECU relearn cold start settings and leave it until it eventually comes back.
2. IACV. Located it and will remove, clean and replace tomorrow.
1. Glitch in the ECU software. Apparently a few have had cold start issues then taken it to Ford who updated the software and has been fine since. Alternatively dc battery for half an hour, let ECU relearn cold start settings and leave it until it eventually comes back.
2. IACV. Located it and will remove, clean and replace tomorrow.
Im on a vehicle techcourse and just had the idle air control valve lessons. Sounds like a classic idle valve failure If the idle valve is working the engine will start, go briefly above idle then settledown to idle, if this doesn't happen then iac valve not doing it's job.
We were told if customer has to keep revving it to make it run, again, iac valve.
Iac valves get signals, or are tied into a few odd other sensors you wouldn't expect, power steering pressure sensor switch for example(you know when you're at full lock and your revs drop slightly, iac stops it stalling!)and the throttle position sensor, which the iac moves in unison with,cleaning the throttle valve plate will help too! (unplug connector on throttle body first!)
If you're iac is stuck open or stuck half way open car will idle really high, stuck closed your problem. The iac can be cleaned but be careful the centre part doesn't pop out when you remove it.
Hope i've got most of that generally correct, i'm in the middle of an info overload melt down just now, my heads full of pintle humps and Zenen dumps! :-)
The iac can be tested when removed and still plugged in,have someone cycle the key on and off when you're holding the iac unit in your hand, just hover you're finger over the end of the centre part of the iac that protrudes, this pintle(the end of it) should come towards your finger, sense where your finger is when it touches it, and retract to a pretermined position where it prepares for acceleration/deceleration events. Again, don't let the centre protruding part come out of the housing! It can be pushed back in though with a slight force then it will readjust itself.
We were told if customer has to keep revving it to make it run, again, iac valve.
Iac valves get signals, or are tied into a few odd other sensors you wouldn't expect, power steering pressure sensor switch for example(you know when you're at full lock and your revs drop slightly, iac stops it stalling!)and the throttle position sensor, which the iac moves in unison with,cleaning the throttle valve plate will help too! (unplug connector on throttle body first!)
If you're iac is stuck open or stuck half way open car will idle really high, stuck closed your problem. The iac can be cleaned but be careful the centre part doesn't pop out when you remove it.
Hope i've got most of that generally correct, i'm in the middle of an info overload melt down just now, my heads full of pintle humps and Zenen dumps! :-)
The iac can be tested when removed and still plugged in,have someone cycle the key on and off when you're holding the iac unit in your hand, just hover you're finger over the end of the centre part of the iac that protrudes, this pintle(the end of it) should come towards your finger, sense where your finger is when it touches it, and retract to a pretermined position where it prepares for acceleration/deceleration events. Again, don't let the centre protruding part come out of the housing! It can be pushed back in though with a slight force then it will readjust itself.
Edited by robbocop33 on Saturday 6th April 08:42
Had another look and the Duratec 1.4 must be the most poorly designed engine ive seen in a while.
It takes the removal of 12 bolts just to access the air filter. To get to the PCV valve its about 2 hours worth of work to first remove the inlet manifold to gain access. I think ive located the idle control valve but again, its impossible to get to.
Luckily I did spot a small vacuum pipe near the idle valve which was completely torn so will replace that first and see what happens.
Tried to photo it but its so ridiculously tight in there i couldnt get a clear image.
It takes the removal of 12 bolts just to access the air filter. To get to the PCV valve its about 2 hours worth of work to first remove the inlet manifold to gain access. I think ive located the idle control valve but again, its impossible to get to.
Luckily I did spot a small vacuum pipe near the idle valve which was completely torn so will replace that first and see what happens.
Tried to photo it but its so ridiculously tight in there i couldnt get a clear image.
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