Invalid injector correction value

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freddyokel
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Joined: 29 Dec 2023, 18:51
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Invalid injector correction value

Unread post by freddyokel »

My 2008 Peugeot 207cc 1.6 HDi has a weird fueling issue so I thought I'd have a quick look with DiagBox to make sure the injectors are coded correctly.
While in there I did a live test on the four 'Injector Flow Correction' values.
Not too sure what I'm looking at but 3 of the injectors have what seem to be sensible values in the 0 to 2 range, but injector 2 is returning 'Value Invalid' and is flat lining at 6.
Does anybody have any idea what this means?
Attachments
injector_2_invalid_correction_no_vin.jpg
freddyokel
Posts: 69
Joined: 29 Dec 2023, 18:51
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Re: Invalid injector correction value

Unread post by freddyokel »

I'm guessing this means the ECU is pushing an extra 6mg per squirt into injector 2 (at idle!) which is then just coming straight back out of the low pressure return.
My leak back test kit arrives soon so I'm suspecting this will confirm that I might need to replace injector 2...
freddyokel
Posts: 69
Joined: 29 Dec 2023, 18:51
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Re: Invalid injector correction value

Unread post by freddyokel »

Now I've learned that the '6' is a reduction. So the ECU is almost shutting down injector 2 at idle as it's leaking so much back to the low pressure return (detected by a lowering of rail pressure maybe)
Gonna do the leak back test tomorrow and I suspect it may be dramatic.
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Rp0thejester
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Re: Invalid injector correction value

Unread post by Rp0thejester »

Keep us posted
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freddyokel
Posts: 69
Joined: 29 Dec 2023, 18:51
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Re: Invalid injector correction value

Unread post by freddyokel »

Car has just returned an almost perfect leak back test. Urgh...
So why no smoke?
Only thing I can think of is that the heavy negative adjustment at idle is compensating for the a leak which goes away under pressure. So... leaking pilot jet?
But is this enough to cause the P0087 after 3000rpm which is the main problem?
Or... is this injector weirdness a separate problem?
I'm pretty much learning common rail diagnosis on the fly here... :(
Attachments
463116918_10158875780992465_5866287329238653798_n.jpg
viva3200
Posts: 1
Joined: 21 Dec 2024, 17:27

Re: Invalid injector correction value

Unread post by viva3200 »

Hi freddyokel.
I have this problem. I changed the injector on cylinder 2, but there was no change. I don't know what to think anymore?!
Was the problem solved for you?
Best regards
freddyokel
Posts: 69
Joined: 29 Dec 2023, 18:51
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Re: Invalid injector correction value

Unread post by freddyokel »

For a while I was convinced that what the ECU was saying was wrong.
But... I disconnected the battery (to replace the fuel filter) and after around 20 minutes off, it would appear that the ECU forgot the correction values.
The engine ran rough, like a misfiring petrol for a few minutes until it gradually became smooth again.
When it stops raining and I have time I'm going to disconnect the battery again and run a leak back test while it's running lumpy. I'll also monitor the correction values to see if it's actually 'relearning'.
So, replacing injector 2. Are you sure you've replaced the right injector? PSA cars number from the gearbox end and not from the cambelt end.