So I have a ford focus 2012 2.0 diesel and for the last week it is struggling to start in the morning but then it will be fine for the rest of the day until the next morning then it struggles to start again, I have used for forscan and it says low fuel rail pressure but if that was the case would it struggle to start all the time ? 

Have you checked the Glow Plugs ?

Not sure how to check the glow plugs ? Can I check them with forscan? Also wouldn't they cause it to struggle to start all the time not just mornings 

Modern diesel engines start fairly easily most of the time provided the engine block is not stone cold. 

The glow plugs only operate for 5 or 6 seconds at start up and only if the engine is really cold. At this time of year they are probably only needed after the engine has stood all night. 

They can be checked using FORScan or with a multimeter. 

 

OK thanks for your advice I will try to find out how to test the glow plugs with forscan 👍

1 hour ago, Alfie0 said:

I will try to find out how to test the glow plugs with forscan

You can't test them with Forscan. You need to use a test meter to check if power is being applied to them and then disconnect the cables and measure their resistance.

Cheers mjt will get my mechanic at work to check them for me 👍

When it does start, do you get a big cloud of white smoke?  That's the usual sign that glowplugs aren't working on a cold start.

If not, I'd suggest it's either a small fuel pipe leak, allowing fuel to drain back overnight, which the pump then struggles to pull forward again.  Or perhaps the fuel filter getting clogged.  Diesel waxes when it gets cold so a bit of heat around the filter can soften it up.

Hi David. What happened in the last week that made you notice that your car was struggling to start? Do you think you may have put some dodgy fuel in somehow? 

From what you say and in this time of year glow plugs are not anything to do with the issue. 

You say your car after it has started then it starts as normal for the rest of the day. So how long during the day is your car stationary? How long is overnight in your case? 

Did you let your fuel tank go so low as to possibly some crud may have been sucked up by the fuel pump?

Tom focus it only struggles in the morning then fine after I can leave it 8 hrs at work and it will start straight away , I have done a diagnostic and it says fuel rail pressroom low bank 1 I clear the code and its gone all day the car starts first time no hesitation until the following morning,  no white smoke , and I'm sure it's not the high pressure fuel pump as I have no other symptoms apart from starting in the morning,  it takes 3 cranks to get it going 

Hi tazzman I haven't changed my fuel station I do use supermarket diesel though but I use miller's additive too. My car is started at 6 am then used at 7 am until 7.45 then parked until 3 pm which it will start first time then it is parked back up at around 4.30 until the next morning where it will struggle to start again.i get a code saying furl rail pressure low bank 1 which I can clear and it does not return until the following morning.  I've read it could be high pressure fuel pump but I am not getting and other symptoms,  the car is perfect once started .

Also no engine light on at anytime 

Hi David. Good to know you use Millers 👍. I've been using it for over 30 years in both diesel and petrol cars I have. I also have used supermarket fuel for ages too in both fuelled cars I've had.

So then 14 hours your car is stood still. To me it smells of fuel in the line has let's say emptied. So when you come to start it it's like the car has to go through a few cycles before it starts. 

To me if a pump is working then basically its working. You mentioned high pressure pump. In diesel cars the fuel pump is high pressure (from what I've read and hear over the years) so in a nutshell. My thought of what's basically is fuel starvation may be correct.

I'm not sure how fuel can work its way backwards but maybe look at that. Its like a slow burn. The pressure in the line over 14 hours has dropped. So somewhere in the line there is an issue. 

 

Yes tazzman it takes 3 turns to get it started but once started it's fine , someone has mentioned a faulty return valve so I'm looking into that now aswell . I changed fuel filter 2 months ago and thought I managed to get all air out . Do you think the filter could be blocked so soon or could there be a air pocket somewhere in the fuel line that I can't get out ? 

3 cranks isn't that many.  Could just be the battery on its way out.  Would be worth checking battery voltage before a cold start imo.

Very unlikely that the filter would block in such a short amount of time.  It is possible that the filter housing is now leaking slightly though.

I have just run my injector balance can someone help me read the results if possible please