Technical Ducato 2.3 2014 - cranks too long, fuel pressure drops immediately after engine turn off

[tomson]

Hi,

I've got the Ducato from 2014 and it usually takes one to three turns more than expected to start the engine.
In the end it starts just fine, but I would expect it to start quicker. Battery is new fine, glow plugs are fine, starter is fine.

I've connected Multiecuscan only to realize that pressure drops from ~300BAR when engine runs to just a couple BARs after I turn the engine off and then turn on the ignition for the OBD port to pick up new values. My hypothesis is that when I start the engine again it takes couple more cranks to build up the pressure, hence the prolonged cranking.

Question is, what shall be the high pressure fail fuel pressure after stopping the engine and for how long pressure shall hold?

In my case pressure rail drops immediately, would that be a symptom of leaky injector, damaged high pressure relief valve or anything else?

Thanks

 

[bugsymike]

Hi,

I've got the Ducato from 2014 and it usually takes one to three turns more than expected to start the engine.
In the end it starts just fine, but I would expect it to start quicker. Battery is new fine, glow plugs are fine, starter is fine.

I've connected Multiecuscan only to realize that pressure drops from ~300BAR when engine runs to just a couple BARs after I turn the engine off and then turn on the ignition for the OBD port to pick up new values. My hypothesis is that when I start the engine again it takes couple more cranks to build up the pressure, hence the prolonged cranking.

Question is, what shall be the high pressure fail fuel pressure after stopping the engine and for how long pressure shall hold?

In my case pressure rail drops immediately, would that be a symptom of leaky injector, damaged high pressure relief valve or anything else?

Thanks

There is differing opinion regarding this, personally I expect after ignition off, pressure to drop fairly quickly but in a steady progression and have seen that on a Scudo 2.0.
If you feel it is slow to build up pressure and drops fast it may be worth doing a leak off test measuring the fuel from the leak off pipes on each injector over a controlled period maybe a minute ? and see if one leaks a lot more than the others.
You can buy a set of blanks to test by bypassing one cylinder at a time to see if pressure improves.
I don't know about your 2.3 , but on some vehicles it is possible to check just the pressure relief valve return/leak off.

 

[tomson]

This issue is now solved after I've replaced 1st injector and cleaned all others: https://www.fiatforum.com/threads/d...00-how-to-connect-the-can.510439/post-4768028

Even though pressure drops to ~6 bar after ignition is off (this is probably how it is in Ducato, since the ECU tells the pressure relief valve to be partially open) the pressure build up during crank start is way faster and car starts almost immediately.

 

[arnelis]

This issue is now solved after I've replaced 1st injector and cleaned all others: https://www.fiatforum.com/threads/d...00-how-to-connect-the-can.510439/post-4768028

Even though pressure drops to ~6 bar after ignition is off (this is probably how it is in Ducato, since the ECU tells the pressure relief valve to be partially open) the pressure build up during crank start is way faster and car starts almost immediately.

Did you manage to program new injector (0445110520) using MES?

 

[tomson]

Unfortunately I didn't, but I drive normally and all seem to be working fine. I even passed the emission test.

 

[bugsymike]

Unfortunately I didn't, but I drive normally and all seem to be working fine. I even passed the emission test.

I have found that to often be the case, even after stripping and rebuilding injectors in the past, but some are less lucky I suppose.
I did help program a set on a 1.3 Multijet using my MaxiEcu scan tool and the owner noticed the improvement.