Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup

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Sat 2 Nov 2013 21:35
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

Hello,

I've got a Mark IV Ford Fiesta (1997, 1.3 Endura-E engine) that's over-revving pretty badly at startup. It only does it when it's cold, but it really screams for 30 seconds or so before the revs start to drop. After a long drive once it's warmed up it goes back to starting and revving perfectly. This model doesn't have a rev counter, but going by ear I'd estimate it's idling at about 2000rpm - you can even drive it in 4th without giving it any gas!

Depressing the clutch doesn't make any difference, so it's not the clutch switch, and disconnecting the sensor on the gearbox makes no difference either.

I've put in a new air filter, new IAVC, used electrical cleaner on all the sensors' plugs and sockets, new breather cap and reset the ECU... All to no avail. Bearing in mind that the car had new oil less than six months ago, has only done 20k miles and is generally treated like a king, what could be up with it? Is there anything I've missed? Any advice from somebody more knowledgeable than I would be greatly appreciated!

P.S. You can see a video of the engine starting from cold and over-revving here: www.youtube.com/watch?v=IqyYm_50BOc

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Sun 3 Nov 2013 12:59
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - dieselnut

Any air getting into the fuel can upset the mechanical pump. Try putting a clear piece of tube in the fuel line just before the pump & check for air bubbles. This will probably have some sort of thermo capsule on the engine with a cable back to the pump to increase the tickover when cold. Check it isn't snagged up & the cable is free.

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Sun 3 Nov 2013 16:08
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - elekie&a/c doctor

Sounds fairly normal to me and does not appear to be at 2000 rpm.If you could get some kind of scanner into the diagostic socket,you would be able to check the exact speed and throttle closed position on the live data.There is no mechanical pump on these it has electronic fuel injection with an electric pump in tank.hth

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Sun 3 Nov 2013 19:04
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - injection doc
I would get the vehicle scanned as elecki doc says

I have seen these fitted with the wrong oil filler cap ! Often bought as an aftermarket part with the WRONG size breather hole and it makes the engine rev very high when cold as it lets too much air in via the breather and with the rich mixture when cold makes the rev high !

If my memory serves me right one of the outlets of the oil filler cap that has a breather hose attached should only have a pin size hole in the end and if it's about1/4 inch it's too big and the wrong cap.

I have sorted several of these out in the past where lots of money has been spent elsewhere and it's just been the wrong cap ! Always worth a check
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Wed 6 Nov 2013 17:08
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

I just checked the oil filler cap and it's got one "normal" side and one pinhole side - I was really hoping it was that! I also checked all the vacuum lines again for holes or cracks (even though that would mean low revs), but everything was perfect.

I did notice that one of the vacuum pipes that runs far away from the engine towards the brake servo was loose. I have drawn a (very poor!) diagram to help explain. Should this pipe be connected to something, or is it supposed to be loose?
www.mattbarney.co.uk/ThisWasLoose.jpg

I will get the car scanned as soon as I can get my hands on a scanner! Thank you for your help!

Edited by MattBarney on 06/11/2013 at 17:08

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Wed 6 Nov 2013 16:58
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

Thank you - I did think it was an injection engine! I'll borrow a scanner and see what comes up. I'll be sure to check the RPM and throttle details when I do. Thank you!

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Wed 6 Nov 2013 18:31
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - elekie&a/c doctor

This pipe is the part of the engine breather system.If one part is not connected or loose,then excess air could be drawn into the engine and the revs will increase.If I recall,the pipe that is detached goes to the inlet manifold/intake pipe.hth

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Sat 16 Nov 2013 19:20
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

Please excuse my tardiness in replying, I've been busy scratching my head over this one!

I plugged the car into a scanner and the recurring code is P0171 - air/fuel mixture too lean, so probably an air leak, would that be correct?

I'm not sure where on the inlet manifold/intake pipe this rogue loose pipe would be - is there any possibility you could elaborate for me?

--

Additionally, I tested the TPS with a multimeter while the car was idling and the voltage is 0.98v - almost a whole volt! Is this correct? I was under the impression that the voltage at the TPS under idle should be around 0.4v.

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Sat 16 Nov 2013 21:33
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

Apologies for the double post; I was unable to find a way to edit my earlier post...

I've highlighted in orange the loose vacuum line I was talking about. Could anybody tell me where this is supposed to go?!

http://www.mattbarney.co.uk/endurapipe.jpg

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Wed 20 Nov 2013 21:54
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - elekie&a/c doctor

If this pipe is flexi black rubber with a green stripe,then it runs to a metal pipe that is secured to the bulkhead ,down below the brake servo and runs to the rear of car.It is part of the evap emission system.hth

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Mon 25 Nov 2013 14:49
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

That's where I reconnected it to. I reset the ECU and have driven it around as normal. Things have improved from before, but on a cold start it still revs up at about 2000rpm before slowly (takes about 30 seconds) dropping to around 850.

LTFTs are -5%, STFTs are 25%+ on startup but soon drop to about 2%. The occasional P0171. Any thoughts, anybody?

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Mon 25 Nov 2013 15:06
Ford Fiesta - Ford Fiesta (Endura-E) over-revving on startup - MattBarney

www.mattbarney.co.uk/fiestastartupgraph.jpg shows a graph of a cold startup taken the other day. Note that it only took 6 seconds to go down to a normal idle speed. Blue is RPM, red is STFT (multiplied by 10, for the sake of readability). Notice how at point 16 the revs are pretty normal but STFT is 41%!

Does all this look okay, or am I missing something?

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