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2003 Mondeo 2.0 Tdci Cutting Out. Codes 0252 And 1121

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Not my car but trying to help a friend who can't use a computer or a scanner. He's the mechanical one and I have ended up doing the computery bit

He started with the problem last November and has been trying to run it to ground, to date he has,

changed or removed and inspected all flexible pipes in the intake system so no splits.

changed MAP, MAF, Crank and Cam sensors

changed fuel filter for reputable make (Bosch)

cleaned EGR valve and fitted/remove/refitted EGR blanking plate

checked the Cam sensor voltage (it's 12V not 5V)

bought OBD2 scanner (Gave it to me to use) and I've checked injector codes are correct. The codes are not the ones one Ford's plate but they are the same as the injector codes so the injectors have been change at some time.

The car drives well enough - plenty of power and the economy is still good and no smoking unless provoked. if the thottle is floored several times in a high-ish gear the coil light comes on and the engine usually cuts within a couple of seconds, but as usual with this sort of problem, restarts immediately

It always flags up 0252 fuel injection problem and 1121 throttle position sensor error.

Watching the scanner data for the throttle position there is no evidence that I can seen of a poor signal, but the fuel pressure demand is always about 20-25% greater than the measured pressure.

Has anyone any ideas as I am completely lost as what to suggest next.

Sorry for the rambling post

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Does the TPS readings show all values between 0 - 100% or do they jump and skip between the % readings?I suspect what your looking at here is a bad hose that needs replaceing.

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Thanks for reply.

As I said, he has removed, inspected and replaced all the hoses (except the one closest to the turbo) and there didn't appear to be any splits but I've suggested he looks again more closely as I have read that they are easy to miss first time around.

The OBD2 scanner and Forscan report the TPS as a voltage (0 - 5.0V) and there are three sensor outputs. Two show the same sense so that they should follow each other exactly and the third is an inverse signal (Presumably 5.0 - 0V) but it doesn't seem to cover the same voltage range. The first two travel o - 5V closed to wide open throttle but the third shows the exact inverse shape of curve but only covers about 0 - 3.5V.

At no time have I seen any spikes or jitters in the wave forms when changing throttle opening so why there is a P1121 error I don't know but in desperation my friend has ordered a replacement sensor.

Now I'm lost for ideas so any suggestion is worth following ... hope it isn't injectors.

thanks for the interest

BTW. looking at the crank position status signal it shows mostly an upper Error level or middle Waiting level and only rare (every 3-5 seconds) indications of the lower Synch level. Do you know if this is normal?

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I have to be honest, the specifics about signals and what they should / shouldnt be are pretty low in my knowledge bank!

As for the hose, its worth checking the pipe, although its a slightly different layout, check my signature for replacing a cracked intercooler pipe, so that you may see where one of the fragile area's is. If you have the engine running and put your hand down around there, or if you rev the car and move your hand around the hoses you should hopefully find any split as you will feel the air rushing out.

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Thanks again,

Looks like thats the next job. My friend (rapidly running out of brownie points) is sending for a bucket of jubilee clips so I suppose I'll get roped in to help. I'll post how we get on.

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As an update, all hoses have been taken off again and inspec ted closely and no splits found.

As suggested by mintalkin a leak off test was done and abandoned less than halfway through when the 40ml bottles threatened to overflow. The book seems to suggest 20ml max so new/overhauled injectors are most likely needed, so 2 new ones have been ordered and 2 sent for recon. Could that explain the difference between demanded and measured fuel pressure and even the throttle position sensor error as the MAF would probably not match the throttle demand for air with all that fuel going straight back to the tank.

Let you know how it goes when the parts arrive .... bit slow here in France.

Thanks again

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Sorry about the late reply but parts went astray then I had problems getting emails.

2 new injectors fitted and best of old injectors left in. The car goes better than when first bought so the idea of reconning the 2 worst injectors went out the window and 2 more new injectors ordered but not arrived yet. Must say my mate is over the moon though he has a box of bits that didn't need changing.

Strange that the injectors increased in crapiness from right to left, though!

Thanks to all who helped.

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