W211 low fuel pressure under hard acceleration star code 22e7

[mshah70]

Hello
Owner of merc w211 e220 Cdi 2007
226k

I am having low fuel pressure issues.
Star diagnostic code 22e7
Check high pressure control ‘rail pressure too low’

When i open up the throttle (hard acceleration) going up a hill or on motorway, the engine light comes on and car goes into limp mode.

I used Star to check high pressure control, Quantity control valve, pressure regulator all sensors seem To be in working order.

I tested the low pressure circuit, fuel pump seems to be in working order.

Please i need some help.

 

[John Laidlaw]

Injectors or injector seals. Any weeping around them?

 

[mshah70]

Had injector seals replaced, no weeping at the moment.

 

[mshah70]

I can feel the engine judder while accelerating hard from 70mph, thats when engine light comes on driving on the motorway.
And while driving local it usually comes on while accelerating hard up an incline.

 

[John Laidlaw]

What’s the engine sounding like when not under load? Normal?

 

[mshah70]

What’s the engine sounding like when not under load? Normal?

While on neutral the engine sounds ok, while on D at a standstill it sounds a little rough.

I have tried doing zero quantity calibration prior to this problem which does make the idling smooth.
But after i had this problem even the calibration doesnt seem to make much of a difference.

And generally the performance is gone low in terms of acceleration.

 

[John Laidlaw]

Normally at this point I’d say get it on Star but you’ve already done that!
Injectors themselves would be normal port of call when you mention what you have for me, hopefully more experienced folks on diesels will chip in shortly
Otherwise it’s the usual eliminations MAF etc etc etc. Good luck

 

[mshah70]

But wouldnt MAF sensors or throttle position/ actuator etc show up as a fault on star diagnostics?

The high pressure fuel pump seems to be in order according to Star.

The only thing i havent checked physically is the injectors. Which im not sure how to.

I have done a compression check on star, also done a smooth engine check, everythimg seems ok. Unless im missing something.
I would appreciate some expert advice. Thanks

 

[John Laidlaw]

That’s what I meant when I said Star- indeed those would show up...

 

[bembo449]

spill test the injectors to see if they are leaking back too much

 

[mshah70]

spill test the injectors to see if they are leaking back too much

Can u guide me how to do this or where i can get the proper test kit

 

[alexanderfoti]

spill test the injectors to see if they are leaking back too much

Yes +1

This kit will work:

https://www.ebay.co.uk/itm/6-Cylind...735754&hash=item25d55963d5:g:IMwAAOSwkShY~KJO

 

[bembo449]

I reckon he will find 3 of the 6 will need a refurb , if not all of them

 

[alexanderfoti]

I reckon he will find 3 of the 6 will need a refurb , if not all of them

I agree, especially at that mileage.

 

[Westheath]

It only needs 1 to dump fuel under load it cuts out or runs rough

Just had it today on a Sprinter
customer was advised to replace all injectors (another garage)
one was on full flow and return over 3500-4000 rpm dumping the rail pressure.

Might be an idea if you can get them out and send all off for refurbishment.

Ignore the high rpm on the top right but the values on the left shouldn't be exceeded
when testing in Star.
The Y94 valve is a little high on this image but mostly due to high rpms

 

[mshah70]

I have ordered the leak testors, i will post my findings in due coarse

 

[John Laidlaw]

We got there!
Personally I’d get them all out to refurb, invariably in my experience 1 then 2 then.... you can see where I’m going I guess

 

[mshah70]

We got there!
Personally I’d get them all out to refurb, invariably in my experience 1 then 2 then.... you can see where I’m going I guess

Is it normal for injectors to leak a little fuel?

And where is the best place to get injectors refurbed, im from south Wales.

 

[Westheath]

The maximum permissible return quantity is 3x as large as the smallest return quantity measured.

Target quantity 50ml
run engine till one container reaches 50ml
turn off engine read the lowest amount
then times it by 3 for acceptable maximum return rate.

1=20ml 2=15ml 3=20ml 4=50ml So 3x15ml=45ml injector 4 @50ml is above max return rate 45ml.

1=35ml 2=33ml 3=50ml 4=31ml So 3x31ml=93ml injector return quantities are within 93ml

If test is ok after the above has been performed ...........
give it a full throttle test and see if any of the bottles suddenly fill up,
this indicates an injector/s is leaking off and dumping the fuel rail pressure.

 

[John Laidlaw]

http://www.dtmfuel.co.uk/
Cover your area. Not a recommendation just google!