TDI PD lift pump after engine start

mirrco

Member
Joined
Jun 23, 2016
Location
Slovakia
TDI
1.9 TDI PD ASZ Firrad160 gtd2260vklr MFS
Hello, I cant find truth politics about running lift pump. There is lot of opinion, but there is lot of variations of engines.
My Engine is ASZ 2001 , Ecu FW is modified, modified is glow plugs too, some values is changed.

My situation is - lift pump run only few second after turn on key. After engine start - lift pump not work. Its ok but in winter not.

In winter under -5 celsius, after minute run on road I have error from ECU - 17669 - PD Unit Injector: Cylinder 1 (N240): Regulation Range Exceeded. error is on any injector too. After this error I see ECU error on dashboard indicator and engine not have performance and time preinjection is bad, engine litle waving.
Some white smoke from exhaust. After turn off and turn on key is OK for 20-30 seconds.

After 5 minutes engine run with this error, If I restart engine is ok. The viscosity of fuel is higher in winter and that is problem.

But -If I force lift pump to run continously by wire, I dont have any error. performane is ok too. no white smoke.

The question is> Lift pump run continuously after engine start or only few second on turn key?
, I find on google forums 2 reasons:

1) My situation is ok and there is problem in some part - injectors, tandem pump, fuel pump, regulators, sensors etc
2) Pump must run continuously and is problem with relay or FW in ECU or fuel temp sensor?
There is missing information about politics running lift pump.
For example -
Maybe lift pump run continuosly under 10 degree celsius when engine start, upper 10 deggree lift pump turn off after engine start. Or run continuously or other politics.
When was -32degree is Slovakia my engine fals after start after few seconds , I must turn off engine more times to turning on by key, lift pump.

BEST reaosn for me is - very good when lift pump run when fuel have lower temperature, lower than 0 degree. Problem will be solved. maybe problem withtemperature sensor or values in FW ECU.

More opinios is by old TDI or new, I have octavia ASV too with no lift pump. But hoses to pump is 2x bigger diameter.

I thing by physicaly my lift pump maybe run ON continuosly, because for 260 hp (theoretical peak power from other users) or more from 6mm diameter hosse need some fuel flow and there is problem with small diameter - lift pump with 2 bar can compensate smaller hosses.

Sorry for my english.
 

mirrco

Member
Joined
Jun 23, 2016
Location
Slovakia
TDI
1.9 TDI PD ASZ Firrad160 gtd2260vklr MFS
I thing 90% must pump run continuosly after engine start because there is smal pipes in lift pump, and tandem pump cant sucking this thin pipes and cant suck from "turn offed lift pump" flow will rotating gearing in lift pump (make flow loss too)
 

mirrco

Member
Joined
Jun 23, 2016
Location
Slovakia
TDI
1.9 TDI PD ASZ Firrad160 gtd2260vklr MFS
Today, I make test in VCDS relay and pump in basic setings channel 35, I run pump for 30seconds.That means pump and relays is ok, this will be possie bug in FW in ECU.
 
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