MK7 wont tickover properly

[rattybathead]

2007 Transit 100, 2.4 rwd.
Well, after fitting a new EGR and cleaning the MAP sensor things have improved. The van will tickover from cold but it still hunts and often stalls at junctions. Performance has otherwise always been fine but I really need some help with this! No fault codes showing with my forscan tool, so wondering how to diagnose PCV or SCV faults? I believe this is a common fault and could explain the idle issues.
I could replace the valves myself if needed but not sure about the computer stuff afterwards so I'm a bit stuck!
Reluctant to put it in a garage as money's a bit tight at the moment so any advice would be appreciated.
As a last resort could anyone recommend somewhere local who deals with Transits? DD4 postcode.

[daraioj]

2007 Transit 100, 2.4 rwd.
Well, after fitting a new EGR and cleaning the MAP sensor things have improved. The van will tickover from cold but it still hunts and often stalls at junctions. Performance has otherwise always been fine but I really need some help with this! No fault codes showing with my forscan tool, so wondering how to diagnose PCV or SCV faults? I believe this is a common fault and could explain the idle issues.
I could replace the valves myself if needed but not sure about the computer stuff afterwards so I'm a bit stuck!
Reluctant to put it in a garage as money's a bit tight at the moment so any advice would be appreciated.
As a last resort could anyone recommend somewhere local who deals with Transits? DD4 postcode.

Chances are it's the SCV playing up.
If you look at the rail pressure on idle with forscan you'll see it going up and down... It should stay at 230bar. You'll probably see it dropping to something like 160.
To test the PRV you'll have to check the rail pressure while loading the engine.. meaning accelerate heavily in say 2nd gear from about idle speed. You'll see the pressure climb until it hits 1600 bar. It shouldn't go past that... If it goes way past 1600 then the PRV is gone... But you would have most likely gotten a code.

Once you replace the scv (do get a genuine denso.. from pfjones or somewhere descent) you'll have to run a pump learn and pilot learn using forscan. Also delete the PRV counter and open duration (I think that's what it's called) counter too.

You could try running a pump learn now but bear in mind that if the valve is very worn, once the stored parameter is deleted you might have trouble starting the van again.

Hope that helps and do let us know if you have any doubts..

[daraioj]

That's what it looked like I'm my van.
Replacing the scv fixed it.

[rattybathead]

Just been out and ran a quick fuel pressure check, starting it from cold it seems to fluctuate somewhere between 21000 and 27000 kpa. Should I check it when it's warmed up properly or should the pressure stay constant regardless? I haven't driven it to check it under load yet and I can't get the readings saved as an image to post it in my reply.

[daraioj]

Just been out and ran a quick fuel pressure check, starting it from cold it seems to fluctuate somewhere between 21000 and 27000 kpa. Should I check it when it's warmed up properly or should the pressure stay constant regardless? I haven't driven it to check it under load yet and I can't get the readings saved as an image to post it in my reply.

There's a PID for desired rail pressure which if I remember correctly stays at 230 on idle regardless of the temp.
210 is not that low... It shouldn't stall at 210.
You could have another look when it's hunting badly and/or stalling.

[daraioj]

It might just need a pump learn but as I said before it might not start or idle afterwards so keep that in mind (if you'll need your van for work, etc) and you do need it to idle properly for the learn procedure to succeed.

[rattybathead]

Thanks for the help, I've now got the feeling it's a bit beyond me! Might just have to get someone to look at it even if it's just to pinpoint the fault. Will maybe have another bash at it tomorrow when I'm feeling a bit more confident!
Thanks again!

[daraioj]

Sorry I didn't mean to put you off. It's not hard at all. You'll definitely be able to do it. It's just I don't like telling people yeah go do this and that without letting them know what can go wrong.
What I meant to say is, worst case scenario it won't start or idle after the learn, which means the valve is faulty. Once you replace it the van will start first go and you'll be able to do the learns.. problem solved.

Just don't try the learns 5 minutes before going to work if you work with your van

[knobby1]

Thanks for the help, I've now got the feeling it's a bit beyond me! Might just have to get someone to look at it even if it's just to pinpoint the fault. Will maybe have another bash at it tomorrow when I'm feeling a bit more confident!
Thanks again!

Just download Forscan and get yourself a modified ELM327 and do the job yourself...you'll save yourself heaps of money in the long run. For ~15 sheckles you can set yourself up.

Lord Knobrot

[captainkevey]

my 2.2 transit 06 also hunts on start up when cold and koncks out if i dont keep up the revs also sometimes when its about to go no amount of gas pedal pumping will affect the revs and it stalls and when coming to junctions after depressing the clutch revs drop it passes out again ..when its warmed up its pretty much ok but it will seem to semi stall and then the cog light illuminates ...took it to mechanic he replaced the fuel pump sensor... still had same problem it must be the other fuel sensor ? second one changed still same problem now hes talking about the egr valve replacement ? any help anyone do these fuel sensors need to be re calibrated when fitted ?

[daraioj]

my 2.2 transit 06 also hunts on start up when cold and koncks out if i dont keep up the revs also sometimes when its about to go no amount of gas pedal pumping will affect the revs and it stalls and when coming to junctions after depressing the clutch revs drop it passes out again ..when its warmed up its pretty much ok but it will seem to semi stall and then the cog light illuminates ...took it to mechanic he replaced the fuel pump sensor... still had same problem it must be the other fuel sensor ? second one changed still same problem now hes talking about the egr valve replacement ? any help anyone do these fuel sensors need to be re calibrated when fitted ?

It's the SCV (suction control valve) that needs replacing. That's the valve that controls the amount of fuel going into the pump and therefore the fuel pressure.
The sensors (fuel temperature at the pump and fuel pressure at the rail) should not cause any hunting as far as I know.

SCV


Chances are that after replacing the SCV the van will idle fine. You should still calibrate it though. The calibration process is called pump learn and you'll need either forscan or IDS to do it.

[captainkevey]

is this easy accessible ?

[captainkevey]

is this one ok ?
https://www.ebay.co.uk/itm/Diesel-Fuel- ... 1438.l2649

[daraioj]

is this easy accessible ?

On FWD it's very easily accessible. On RWD it's a bit trickier. Gets much easier if you remove the inlet manifold.

[daraioj]

is this one ok ?
https://www.ebay.co.uk/itm/Diesel-Fuel- ... 1438.l2649

Personally, I'd buy Denso. From pfjones or somewhere descent. It'll cost £45 but that'll be the end of it.
People have had problems with cheap ones.