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Ford Fiesta 1.6 16v Dv6 - Diesel knock, code P0087 low fuel pressure - Fixed #

Posted by Joe Ofarrell on March 15, 2016, 12:19 am

Year of Manufacture *: 2006
Engine Size and Code *: 1.6 16v Dv6
( Optional ) Scanner Used: maxidas & Autocom
( Optional) Fault Codes: P0087 low fuel pressure

Hi,
I have this Fiesta 1.6 dv6 engine, came from a mobile mechanic.
Car runs ok, until under load and loud diesel knock and clouds of black smoke.
New Egr valve, Fuel filter and 4 reconditioned injectors fitted previously.

Carried out various tests. Fuel quality ok, checking specific gravity. Found injector correction factors had not been done, coded in and still the same, carried out leak off test and found excessive leak back, one injector had twice the amount.
Sent back injectors to diesel specialist. He said nothing wrong with them within tolerance?
Refitted and retested leakback, had improved, ( suspect diesel specialist had made some adjustments ) leakback within 20 %.
When low fuel pressure code is set when driving,and knock occurs, the rail pressure is 10500 psi and drops to 6000 psi.

Scoped the injectors in the workshop and all patterns identical and look ok.
I suspect these are bad injectors, how can I prove this.
Other than sending them away elsewhere to test or fit new injectors.

Any suggestions appreciated.

Thanks

Joe

Re: Ford fiesta.Diesel knock

Posted by Shane Gray on March 15, 2016, 8:09 am, in reply to "Ford fiesta.Diesel knock "
Shane Gray

Morning,
Has the valve timing been checked?
Shane

Re: Ford fiesta.Diesel knock

Posted by Chris Angus on March 15, 2016, 3:14 pm, in reply to "Ford fiesta.Diesel knock "

Bit of a tricky one that, you would assume that if a specialist is testing injectors and they say they're ok, then they must be.

I think you need a better test plan.
Are you able to graph the fuel pressure and drive it til you hear knock, it could be that the pressure is just too high and causing the knock, does your live data show specified and actual fuel pressure values?

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Does the knock and black smoke happen at 10550 psi or 6000psi? What rpm and boost pressure are you at this time?

Re: Ford fiesta.Diesel knock

Posted by joe O'farrell on March 15, 2016, 4:07 pm, in reply to "Re: Ford fiesta.Diesel knock "
Joe O'farrell

Thanks for the replies,

I haven't checked valve timing yet.

I have graphed the fuel pressure on live data and the fault occurs at 10500 psi every time drops to 7000 psi,and triggers low fuel pressure code, when under load.

I will try another scanner to see if it lists actual and desired as maxidas doesn't list desired pressure.

Thanks

Joe

Re: Ford fiesta.Diesel knock

Posted by Chris Angus on March 15, 2016, 4:18 pm, in reply to "Re: Ford fiesta.Diesel knock "

Is the knocking and smoke at 10500 or 7000 then?

Re: Ford fiesta.Diesel knock

Posted by joeO"farrell on March 15, 2016, 5:28 pm, in reply to "Re: Ford fiesta.Diesel knock "
Joe O'farrell

Knocking and smoking at 10500 psi,
Dash display indicates engine system fault, and logs low pressure code.

Re: Ford fiesta.Diesel knock

Posted by andy pethig on March 15, 2016, 8:49 pm, in reply to "Ford fiesta.Diesel knock "

is this system a delphi ??

i am not at work at the time of typing so can not look it up.

if it is a delphi, ring there technical help line and get them to email you over there manual for the system and ask for it to include what criteria the pcm needs to see in order to set the code.

included in the code description will be a flow chart on how to trouble shoot the problem.,

i have used the service a number of times and its free.

S C MOTORS gave me the number

if its bosh or some other i am sure they may have a tech line you could call.

Re: Ford fiesta.Diesel knock

Posted by Chris Angus on March 16, 2016, 12:09 pm, in reply to "Re: Ford fiesta.Diesel knock "

See if you can log rpm and mass fuel desired when it knocks, I have a few fuel maps for these so I might be able to tell you what the fuel pressure should be.

Re: Ford fiesta.Diesel knock

Posted by Craig Thompson on March 17, 2016, 7:57 pm, in reply to "Re: Ford fiesta.Diesel knock "

That sounds good Andy, any chance of posting that number?

Re: Ford fiesta.Diesel knock

Posted by Joe O'Farrell on March 17, 2016, 9:00 pm, in reply to "Re: Ford fiesta.Diesel knock "
Joe O'farrell

Thanks for all the help

The system is Bosch. With a Cp1 H pump.

I managed to speak to the Bosch technical support Diesel specialist. Andrew Page gave me the number. I will post tomorrow.

He suggested injector fault, and that there are only a handful of people in the country who can test these injectors properly.

Below is a graph of rail pressure and Rpm

Thanks

Joe

Re: Ford fiesta.Diesel knock

Posted by Joe ofarrell on March 17, 2016, 9:23 pm, in reply to "Re: Ford fiesta.Diesel knock "
Joe O'farrell

Please ignore vehicle description this is a Fiesta

The diesel knock is really bad between 65 and 75 seconds on the time scale.

Ideally I need to scope the rail sensor and rpm, I will try tomorrow as access is very poor .

None of my scan tools read desired fuel pressure, but you can see the pressure rising and falling quite quickly when fault occurs

Thanks
Joe

Re: Ford fiesta.Diesel knock

Posted by Tim Watts on March 18, 2016, 12:03 am, in reply to "Re: Ford fiesta.Diesel knock "
Tim Watts

Do you know if the injectors where replaced to address this fault or if the fault has come about since the replacement?
Is it possible to check rail pressure with a manual gauge and maybe monitor pressure sensor output voltage at the same time just in the case that the switch circuit is maybe shorted/open.
It's not something I have tried but would it be possible to disconnect individual injectors and test as before only on 3 cylinders, just in case one injector is sticking open.
A mechanic I know used to put a small ball bearing in the injector feed pipe to block fuel flow and run them on three cylinders until he eliminated each one.

Fixed #

Posted by Joe Ofarrell on April 2, 2016, 8:50 am, in reply to "Re: Ford fiesta.Diesel knock "
Edited by board administrator April 4, 2016, 3:50 pm

Car now been ok for a week,

Diesel knock was the original fault before any parts were fitted.

Tested each injector individually with ball bearing.

Fault still the same.

Tried to gain access to the rail pressure sensor wiring, but impossible without removing the starter motor etc.

Removed headlamp to gain access to the sensor wiring, at the ecu and found the lear connectors broken, on one of the ecu plugs, Resecured connector tested and car ok.

Suspect vibration when accelerated gave a poor connection, as I could not reproduce fault in the workshop.

Thanks again for the help.

Regards

Joe

Bosch technical support number is 01895878197

Re: Fixed #

Posted by Craig Thompson on April 7, 2016, 10:52 pm, in reply to "Fixed #"
Craig Thompson

Thanks Joe 👍

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