CP1 type rail pressure pump and 3rd piston de-activation

by **dbwarrior** » Tue Jul 12, 2016 9:43 am

I had been studying that CP1/R65 type pump has 3rd piston de-activation functionality.
I am confused now that on my system is that 3rd piston ever on working normally. Some HDI manuals are saying that 3rd piston is only working for post- injection. And if fuel temp go over 100degree it dropped that 3rd piston away.
Also i had been logging that 3rd piston activity during WOT and log says for "3rd piston de-activation"= active hole acceleration duration from 1500 to 4500rpm. Even that rail pressure after 4000rpm is over 1500bar.
I fully understand that orginal 50mm3 at 1350bar doesn't need that 3rd piston to get working, but now i am wondering does is ECU command that 3rd piston to work in any driving condition.

So what kind of experiences other EDC15c2 users has ?

by **dbwarrior** » Tue Jul 12, 2016 6:14 pm

Does any one info will enabling 3rd piston increase output quanity ?
Example by running 2 pistons on 4000rpm pump can do 100mm3@1600bar and enabling 3rd piston pump can produce 130mm3@1600bar.

Or is 3rd piston functinality total diffrent and main reason is produce some extra IQ for post injection purpose...

by **dbwarrior** » Wed Jul 13, 2016 9:51 am

What you think about these calculations:
IQ 80@4000rpm is needing from rail pump 2*80*4000=640 000mm3 per minute( 640cm3 per minute)
Pump model is R65 and this is equal than 650cm3 per minute(what RPM ? )

Does this mean that all 3 pistons is needed for producing that 650cm3 what is specified to that rail pump ?

by **alex_sk** » Wed Jul 13, 2016 11:53 am

Where you find info about separately controlled pistons in CP1?
https://www.youtube.com/watch?v=WQsBMPLYMDA

by **dbwarrior** » Wed Jul 13, 2016 12:21 pm

Youtube video was concerning cp1h.

2.0L 8V hdi's is equipped CP1s
Here is on document:
http://injectionpumps.co.uk/pdf/Bosch_CP1.pdf

I already has found 16x8 map what is giving some kind of "100 / 0" info when 3rd piston is possible to working.
Maybe i will just change that map and then make new log. Maybe even put multimeter to 3rd piston solenoid for seeing that is logging giving wrong info.

by **alex_sk** » Wed Jul 13, 2016 10:42 pm

Tnx! Now I know about CP1S.

by **dbwarrior** » Thu Jul 14, 2016 6:49 am

I was studying that "EDC 15C Funktionsbeschreibung" and there was well documented that pump is working always 3piston when starting engine.
So this morning i was logged that situation and ques what. Lexia log file was showing same 0 than all other tests. I am pretty sure that logging is the problem. Next i will measure voltage from solenoid when starting engine. If it drops to zero, it is sure that logging is giving wrong info.

by **alex_sk** » Thu Jul 14, 2016 11:03 am

My area is Renault and thay began use CP3 from 2002.

by **dbwarrior** » Thu Jul 14, 2016 8:37 pm

An now it is tested and confirmed. Lexia logging is broken for 3rd piston de-activation.
Multimeter was showing correct behauviour of 3rd piston de-activation.

by **ecuedit** » Thu Jul 14, 2016 10:09 pm

dbwarrior wrote:An now it is tested and confirmed. Lexia logging is broken for 3rd piston de-activation.
Multimeter was showing correct behauviour of 3rd piston de-activation.

some variants of 2.0HDI 90hp and 110hp has no valve on pump for deactivation 3rd piston.
There is codeword in flash where it is set up if that valve is present or not. When using all 3pistons you get more
stable rail. you can make all pistons running by changing codeword or disconnect plug and delete dtc.