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Ford Focus 1.8 TDCi 2006 - Code P0089 Fuel rail sensor #

Posted by Liam Hourihan on July 24, 2013, 12:21 am

Year of Manufacture *: 2006
Engine Size and Code *: 1.8TDCI
( Optional ) Scanner Used: launch
( Optional) Fault Codes: p0089 Fuel pressure sensor

This car was towed to me after it broke down while driving.The car had been in another garage last week with the same fault and another fault relating to an egr valve.
I cleared the codes but p0089 reappears after a couple of try,s of starting .On live data the pressure isn't reaching the the requirement for 280 bar for starting.
I have put a gravity feed of diesel to the pump in order to bypass the filter housing.A leak back test shows the injectors seem OK and have equal amounts of leak back, and it doesn't seem excessive .The rail sensor has a 5v feed ,0.05 earth and 0.5v signal ,when the ignition is on. But on cranking the signal voltage drops to between 0.2v and 0.3v.
Shouldn't the signal volts stay at 0.5v on cranking and raise to 2v when idling regardless of pressure or it it because of the load from the starter causing the signal volts to drop momentarily.If I disconnect the imv valve shouldn't the rail pressure rise to 4.5v when cranking ,and if not is it more than likely the pump.

Re: Ford Focus P0089 Fuel rail sensor

Posted by Kevin Apps <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2589' width='330' height='300' border=0 style='border:none;'> on July 24, 2013, 3:29 pm, in reply to "Ford Focus P0089 Fuel rail sensor"
Kevin Apps

Liam.

"The rail sensor has a 5v feed, when ignition on" does this remain so on cranking ?

Kev.

Re: Ford Focus P0089 Fuel rail sensor

Posted by Phil Madeira <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat1479' width='330' height='300' border=0 style='border:none;'> on July 24, 2013, 10:13 pm, in reply to "Ford Focus P0089 Fuel rail sensor"
Philip Madeira

I had the exact same fault with a mondeo 1.8 tdci last week. It turned out to be the plastic fuel supply pipe had rubbed through as it passes over the timing belt cover. The fault code relates to insufficient fuel pressure - it was drawing air in. I know you have substituted the supply, have you tried easy start to get it started?
Phil

Re: Ford Focus P0089 Fuel rail sensor

Posted by Liam Hourihan <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1040' width='330' height='300' border=0 style='border:none;'> on July 24, 2013, 11:10 pm, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Liam Hourihan

I never checked the 5v feed when cranking and I have not tried to start it with an easy start.I did get a loan of a good second hand rail assembly with sensor from my dealer today but it still didn't start.I will check the feed in the morning and try easy start.

Re: Ford Focus P0089 Fuel rail sensor

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on July 25, 2013, 7:12 am, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Carl Ford

Can you post the waveform with 3 channels of the rail pressure sensor, 5v ref, signal and ground from KOEO then cranking and then off.

Carl

Re: Ford Focus P0089 Fuel rail sensor

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on July 25, 2013, 10:25 am, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Mark Carter

Have you got any fuel at the pump ?

Is the low pressure supply pump working?

Mark

Modern cars, Its all wizardry and witchcraft

Re: Ford Focus P0089 Fuel rail sensor

Posted by Malcolm Probert <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3493' width='330' height='300' border=0 style='border:none;'> on July 25, 2013, 9:18 pm, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Malcolm Probert

Low pressure pump on a Focus? That's news to me? The only time I've had that code, was a week after another garage had renewed the filter element. I tightened the retaining ring by about 1/2 turn. It didn't come back.

Re: Ford Focus P0089 Fuel rail sensor

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on July 26, 2013, 10:43 am, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Mark Carter

>>> Low pressure pump on a Focus? That's news to me? <<<

Look inside the Delphi CR pump and you will find a low pressure vane pump that draws fuel from the tank.

It should be tested just the same as any other low pressure system. If it can not draw fuel for what ever reason the vehicle will not generate the correct high pressure.

Just because it is internal is not a reason to ignore it and assume it's OK.

Mark

Modern cars, Its all wizardry and witchcraft

Re: Ford Focus P0089 Fuel rail sensor

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on July 27, 2013, 7:52 pm, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Carl Ford

Hi Liam

Do you have that waveform I asked for? I have a theory about your negative voltage whilst cranking which may help you along in your diagnosis(may not also

)

Regards
Carl

Re: Ford Focus P0089 Fuel rail sensor

Posted by Liam hourihan <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1040' width='330' height='300' border=0 style='border:none;'> on July 29, 2013, 11:14 pm, in reply to "Re: Ford Focus P0089 Fuel rail sensor"
Liam Hourihan

Green :Imv signal
Yellow : Amp clamp on imv valve
Red : Signal from fuel rail
This is the image when cranking the engine ,the rail pressure doesn't seem to go over 1volt even when I have fuel going into the pump under pressure from an in line hand pump.The 5v feed is constant while cranking and I will get the wave form you requested tomorrow Carl.

Re: Ford Focus P0089 Fuel rail sensor

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on July 30, 2013, 8:47 am, in reply to "Re: Ford Focus P0089 Fuel rail sensor"

I thought you said you had lower than 0.5v on cranking but the above waveform suggests that you have nearly 1v on cranking (I may have just read an earlier post wrong

)

Still worth grabbing the capture I asked for

as I think it will show up a possible leak.

Carl

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