Zero Fuel Pressure - Possible Causes?

[Surfless]

morning all,

I've got a poorly S-max - mine is a 1.8 TDCI on a 58 plate.

On the motor way on Wednesday this week after a decent run from Cardiff to Portsmouth, the engine lost all power and stalled at around 40mph in the fast lane of the M27 - I coasted across traffic to the hard shoulder, had AA come out and he checked Cambelt, battery, Alternator and concluded from a risky diagnosis on the side of a busy motorway in the dark that it was likely fuel related.

Towed to a mechanic friend of mine, recharged the now flat battery, and the diagnostic is showing no error codes at all, but its also showing zero fuel pressure.

I know this sounds like the fuel pump, but this is a relatively expensive solution which I don't want to dive into before I am 100% its the issue.

I am hoping someone on here might have experienced this before and would be able to give me a steer as to what it may be?

Any help gratefully accepted.

Cheers

Phil

Surfless

[steve44]

Zero fuel pressure sounds like something has sheared in the fuel pump

Would be worth checking the fuel pressure sensor is reading correctly and running a direct supply of diesel to the fuel pump to rule out any blockages first though

[Surfless]

howdy all.

For the benefit of future searches, I'm going to outline the process I went through today, and then explain what actually was wrong.

We checked Cam belt, alternator, and electrical connections to be sure it was a pump issue, previously - today we went to looking at the rail, and the fuel filter.

When we checked the fuel filter we found that when it was replaced by the AA a month ago, the cap on the housing was not screwed back on properly. This caused the car, each time I switched the engine off, to suck in a minute amount of air. Over the following month, the car got progressively lumpier and lumpier, struggling to start, often not starting without substantial throttle, and then started on Wednesday to misfire periodically. When the AA guy turned up on Wednesday to collect me from the side of the road, it was too dark and dangerous in rush hour to try to check this, hence he missed that the fuel filter housing only had about a third of the container full of diesel.

Today finally, after 2 - 3 hours of frustrating priming, we got the beast running again.

Advice if you do have to do this - have a vacuum hand pump to prime the bleed valve on the fuel filter housing, and a good quality battery charger, as its very likely your battery will die at least once before you get the air out of the system.

Thank you Steve44 for your comment - much appreciated - hope this helps people going forwards.

[BAD DOG]

Hi Surfless

I'm going thro a simular problem with my S Max.

After a number of visits to the garage, who I hold in regard, and after a number of RAC call outs, the conlusion is an intermitant air leak in the low pressure side of the fuel system. Trying to find the problem is like finding the Holy Grail.

[Surfless]

Bad Dog that is exactly what I am experiencing at the moment - since the post above when I thought I'd repaired the issue, I've had several instances where the smacks has decided not to start in the mornings, randomly in the afternoon, and pretty much any time of day.

I have concluded that persistence pays and eventually it will start, however there's the concern as to what that is going to do to my battery, starter motor and alternator over time - thankfully I've not lost full pressure since becoming a rolling roadblock on the M27, however given that its completely unpredictable, I suspect eventually I will again become a danger to traffic.

Let me know if you do find where it is, I doubt very much that there's a pattern to it, but it will at least give me somewhere to start looking when the time comes.

[BAD DOG]

Smax is booked in for next week, um one of my issues that I identfied is parking facing up a gradient.!!!! (when the fuel drains back into the tank)

Sounds if you got a bigger problem, one thing, have you got any fuel leaks from the fuel lines? i havent

[BAD DOG]

Garage still cant detect it, reffered me to a specialist auto diesel centre. Things can only get worse, looks like an injector is playing up as well!!!!!!!!!!!!!!!!!!

[iantt]

If your experiencing air leak in to low pressure system, more than likely its the fuel supply pipe rubbing by the top engine mount, cant remember what it rubs on, done 3 smax/ galaxy .

it draws air in but rarley you see a leak as such , may be a smear on finger.you feel the pipe to find it as its such a small rubbing hole.

it will be worth checking.

[187469]

The above sounds like an issue just identified on my Galaxy TDCi 2007. Engine stalled and would not start having been on slight incline with front of car raised. AA man identified a lack of pressure in fuel system. AA man took off engine cover and found air in fuel lines, clear tubes entering injectors. He spotted one of the fuel pipes on the left hand side top of engine had been rubbed and looked as if there was a slight cut in pipe. Temporary taped up and air vacuum pumped out and car started. On replacing large plastic engine cover, clever AA man compared the left hand edge where it sat over the fuel pipe and spotted a shiny area which looked like it had been rubbing. AA man then noticed that one of three rubber bungs which sits under the engine cover and locates on three spigots to secure it over the engine, was missing thereby allowing the plastic engine cover to sit lower and rub the fuel pipe. Anyone know where to find diagram of engine parts so I can identify the pipe to be replaced and find part number?

[Macstef001]

Hello, my Smax keep randomly going into limp mode with Engine Malfunction warning. The fault that keeps registering is Fuel Rail Pressure (Intermittent/Erratic). The problem is the fault keeps resetting itself after the engine is switched off for a few hours so by the time its in a garage for repair (3 times now) they can't detect the fault and fix it. The best guestimate is that its the fuel pressure sensor on the rail. However I understand its not possible to replace just the sensor on an Smax and the whole rail would have to be replac ed (£500 with labour). Its an expensive gamble.

Has anyone experienced this problem and is it correct to assume its a sensor fault?

 

Thank you.

 

Maciek

[Oke39]

Did anyone have any solution to this in the end I've a 2006 2.0 tdci s max and what surfless has put is the same as what I'm having trouble with, with mine 😞

[Kirky70]

I've got a similar problem no fuel in pipes can get fuel back by using a hand pump on fuel lines it then starts but cuts out within a week air getting pipes some how low fuel pressure on diagnostics machine

[ntom]

Had a similar problem on 2.0TDCi S-Max, whereby air in the system was causing a failure to start if left for more than a day or so.  Can alway get it going evenually using a pump on the return pipe as per this video:

https://www.youtube.com/watch?v=KdoE6-QmAoo

However tracking down the source of the problem took ages.  There's clearly bubbles in the fuel line even when running. It gradually got worse & then today when engine was turned off I could hear a fizzing of air which sounded like it was coming from the union of the supply side line into the filter housing.  Thought I'd take the housing off & take a closer look at the connector which looked like its removable.  Then as I lifted the incoming fuel line away I noticed a rub mark on the fuel line where it passes some electrical cable.  Voila.  A bit of tape around the line & put it back together.  No sign of air in the line at all.  When I looked on-line I notice that there is like a nylon protective sleeving in most pictures which isn't present on mine -probably why over the years the rubbing has worn through the fuel line. Not enough to cause an obvious fuel leak yet but it allows air in as fuel flows back to the tank when the engine is shut down.

Hope this helps someone.  Been driving me nuts for a few weeks now and Ford were suggesting a new pump!!

 

[paddyg816]

On 1/7/2020 at 4:00 PM, ntom said:

Had a similar problem on 2.0TDCi S-Max, whereby air in the system was causing a failure to start if left for more than a day or so.  Can alway get it going evenually using a pump on the return pipe as per this video:

https://www.youtube.com/watch?v=KdoE6-QmAoo

However tracking down the source of the problem took ages.  There's clearly bubbles in the fuel line even when running. It gradually got worse & then today when engine was turned off I could hear a fizzing of air which sounded like it was coming from the union of the supply side line into the filter housing.  Thought I'd take the housing off & take a closer look at the connector which looked like its removable.  Then as I lifted the incoming fuel line away I noticed a rub mark on the fuel line where it passes some electrical cable.  Voila.  A bit of tape around the line & put it back together.  No sign of air in the line at all.  When I looked on-line I notice that there is like a nylon protective sleeving in most pictures which isn't present on mine -probably why over the years the rubbing has worn through the fuel line. Not enough to cause an obvious fuel leak yet but it allows air in as fuel flows back to the tank when the engine is shut down.

Hope this helps someone.  Been driving me nuts for a few weeks now and Ford were suggesting a new pump!!

 

just out of curiosity i have the same engine in my diesel grand cmax and my issue is fuel pressure , would happen to know where the regulator in the engine bay is located do you  ?