Since last changing fuel filters (gen/ren) the truck is incresingly hard to start, spins over longer and needs some right foot.
Any ideas?
Steve’s the man here, if I had to guess I’d say it sounds like fuel is running back from the injectors under gravity when it is parked. Does this tend to happen more the longer it has been parked up?
Maybe air getting in? Check the filters ,unscrew them & put some grease or diesel around the rubber seal & screw them on again? Hand tight. If theres a load of white smoke its def air.
who changed your filters? check for air due to wrong positioning of filters sealing I think…
It could well be air getting into the system but generally this brings up the “fuel supply fault” whilst it’s cranking over. There is a residual pressure type valve that’s on the return pipe out of the head which sometimes gives this symptom. The return comes out of the front of the head and it looks just like a banjo bolt.
Steve
I will start by saying I know nothing about Renault,and would never doubt neversweat1advice …My only suggestion, which I had last week by chance on a DAF that after having the fuel filters changed was then taking 30 secs to start …After speaking to the lad who did the filters and asking how he bled it …My theory being if it drove in ok,and the issue started after the filter change ,then it was something we had did…Turns out the bleed screw on the pre-filter housing has an alloy washer which was corroded,fitted a copper washer and all was well …Seconds to diagnoise
norb:
I will start by saying I know nothing about Renault,and would never doubt neversweat1advice …My only suggestion, which I had last week by chance on a DAF that after having the fuel filters changed was then taking 30 secs to start …After speaking to the lad who did the filters and asking how he bled it …My theory being if it drove in ok,and the issue started after the filter change ,then it was something we had did…Turns out the bleed screw on the pre-filter housing has an alloy washer which was corroded,fitted a copper washer and all was well …Seconds to diagnoise
We don’t have to crack anything off to bleed them - Just pump the primer umpteen times.
The troublesome filter is usually the pre-filter as you have to change the clear bowl over off the old one where as the main filter is just a spin on one. The advantage of the bowl is you can normally see any aeration in it - Normally 
Steve
I’m to lazy to use the hand primer ,I just put 0.2 bar pressure in to the tank with my modified cap and regulator lol…Really useful when the fuel system has been drained
neversweat1:
It could well be air getting into the system but generally this brings up the “fuel supply fault” whilst it’s cranking over. There is a residual pressure type valve that’s on the return pipe out of the head which sometimes gives this symptom. The return comes out of the front of the head and it looks just like a banjo bolt.Steve
Hmmm thats interesting, have had the problem a few months back, with fuel supply warning, changed fuel filters, pre filter full of gunk, all was good.
So figuring I had bought some crappy fuel I decided to do filters again.
So the valve is worth investigating.
Thanks for the feed back folks, I will update when resolved.
Barry
bazstan009:
neversweat1:
It could well be air getting into the system but generally this brings up the “fuel supply fault” whilst it’s cranking over. There is a residual pressure type valve that’s on the return pipe out of the head which sometimes gives this symptom. The return comes out of the front of the head and it looks just like a banjo bolt.Steve
Hmmm thats interesting, have had the problem a few months back, with fuel supply warning, changed fuel filters, pre filter full of gunk, all was good.
So figuring I had bought some crappy fuel I decided to do filters again.
So the valve is worth investigating.Thanks for the feed back folks, I will update when resolved.
Barry
If that’s the case Barry I’d get all the fuel pipes blown out - A bit laborious I know but especially at the connections by the filter head.
Steve
Baz, do you generally fuel up at the same place? Some places sometimes have issues with fuel quality, particularly as their storage tanks get older and start to degrade. I believe Silveys had issues with this a few years ago at Chippenham Truckstop.
In your position I think I’d try a new fuel filter first, making sure you lubricate both sides of the rubber seal when you fit it.
This may sound daft but in the front cranckshat pulley there is a centrifugal oil filter, have you ever cleaned this out. Also check the bleed screw washers and filter seals plus clean out pre-filter,also if you cracked off any injector pipes check they are sealing correctly. 
Harry Monk:
Baz, do you generally fuel up at the same place? Some places sometimes have issues with fuel quality, particularly as their storage tanks get older and start to degrade. I believe Silveys had issues with this a few years ago at Chippenham Truckstop.In your position I think I’d try a new fuel filter first, making sure you lubricate both sides of the rubber seal when you fit it.
Made a point of being fussy since last year, had a load of problems that I think were in part due to bad fuel or adblue!
You have nipped a filter seal.Called the syphon effect.Air is lighter than fuel.
Replace the tank sender.
I thought we were talking about a Maggie D.If you share the name with that beast you will have problems for eternity.
Worked through the above tips without the result I was hoping for.
It got worse then would get reluctant to pull so had a few test done and then had injector sleeves replaced.
Am poor again but motor running well 