INTERNAL DIESEL INJECTOR DEPOSITS

INTRODUCTION

IDID – What is it?

DW10C CEC engine test development

DW10C engine testing – Innospec testing

Vehicle Testing

Conclusions

INTERNAL DIESEL INJECTOR DEPOSITS (IDID)

Field issues reported where injector needles had stuck

Problems associated with IDID include:

Noise, especially when cold

Cold start problems, or even failure to start

Rough running and erratic idle

Power loss and poor acceleration

Possible bad actors

Metal contaminants in fuel (Sodium, Zinc)

Some additive components, e.g. Low Molecular weight PIBSI detergents

INTERNAL DIESEL INJECTOR DEPOSITS (IDID)

Deposits can build-up

higher up in the injector

body

The needle only has a

couple of Microns

clearance to the outer

body

Tiny amounts of deposits

can cause the needle to

stick in the body

TYPES OF DEPOSITSPOSSIBLE SOURCES

Temperature

at injector in common

rail engine

Bio-contamination

aerobic/non-aerobic

Lube oil

adulterationAdditive Misuse

Additive/

reaction/degradation

Bio-diesel

Water/Dirt

Fuel

Metallurgy &

metal catalysts

Bio-diesel

blend storage

sediment

Pressure

at injector in common

rail engine Fuel thermal

stress in common

rail engine

Injector & Filter

deposition

Pressure

at injector in common

rail engine Fuel thermal

stress in common

rail engine

Temperature

at injector in common

rail engine

Metallurgy &

metal catalysts

TYPES OF DEPOSITS

Numerous causes for fouling, but three basic types exist:

Metal carboxylates white, soapy deposits, usually Na related

Carbonaceous Black deposit typical of degraded fuel

Amide-lacquering type reported to be linked to some detergents

Injector deposits are mostly carbonaceous and caused by fuel oxidation-

degradation (SAE papers, CRC panels, OEM discussions, etc.)

Effect of temperature/pressure in newer HPCR injection systems

increases the amount of deposits formed (all types)

TYPES OF DEPOSITS

Metal CarboxylateCarbonaceous

Amide Lacquer

INNOSPEC SAE PUBLICATIONSPaper Description

SAE 2009-01-1877 Analysis of injectors and fuel filters by a range of analytical techniques

SAE 2009-01-1878 Review of fuel stability literature and Industry Standard stability test data

SAE 2009-01-2637 Use of a novel technique, hydropyrolysis, to analyse deposits

SAE 2010-01-1475 Use of temperature programmed oxidation (TPO) to analyse diesel deposits

SAE 2010-01-2243 Characterisation of fuel and injector deposits by various analytical techniques

SAE 2011-01-1923Historical review of deposit formation in diesel engines and development of test methods to assess fuels and

additives & further hydropyrolysis analysis of filters and injectors

SAE 2012-01-0867 Loss of HFRR performance with acidic lubricity improvers when fuel contacts caustic, no loss with ester additives

SAE 2012-01-1865 Introduces the use of ToF-SIMS (Time of flight secondary ion mass spectrometry) to analyse deposits

SAE 2013-01-2687Sodium contamination of diesel fuel, its interaction with fuel additives and the resultant effects on filter plugging and

injector fouling

SAE 2013-01-2682 Understanding polyisobutylene succinimides and internal diesel injector deposits

SAE 2014-01-1388 Internal injector deposits from sodium sources

SAE 2014-01-1387Information on the aromatic structure of internal diesel injector deposits from time of flight secondary ion mass

spectrometry (ToF-SIMS)

http://www.innospecinc.com/about-us/research-and-development/technical-papers

INTERNAL DIESEL INJECTOR DEPOSITS – CEC TEST DEVELOPMENT

Test development complete using DW10C engine

1997cc

4 cylinders in line

Common Rail

4 valves per cylinder

120kw @3750rpm

340Nm @ 2000rpm

Euro 5 compliant, Delphi injectors

DW10B DW10C

Made by Continental Made by Delphi

Euro 4 Euro 5

Prototype nozzle design, found

to increase fouling effect

Standard Production injectors

Piezo type operation Solenoid type operation

6 injection holes in nozzle 8 injection holes in nozzle

1600 Bar injection pressure 2000 Bar injection pressure

DW10B VERSUS DW10C INJECTORS

DW10C – CEC IDID TEST

DW10C is an official CEC test

Coded CEC F-110-16

Cost per test approximately EUR 15000 including reference fuel cost

Test moved ahead with only Na + DDSA procedure

Test reproducibility = 1 Merit

Performance of ECOCLEAN® technology is excellent

DW10C – TEST CYCLE

High speed/load test

conditions

1 hour cycle repeated 6

times

Followed by 4 hrs cold

soak

Above repeated 5 times

Cold starts rated in

between phases

DW10C – DEMERIT SYSTEM

Test has a complex rating system

Based on Demerits

Combination of 6 different parameters

2 parameters during cold starts

4 parameters during running phase (Operability)

Creates numerous opportunities to lose merits

Maximum of 75 merits available to lose

Final result then divided by 7.5 (Don’t ask…!!)

0.5PPM NA + 10MG/KG DDSA – BASE FUEL

Engine ran for 18hrs,

but would not re-start

after soak period.

DW10C TESTING – ECOCLEAN™

Exhaust Temps

stayed the same

from SOT to EOT

Excellent IDID

protection

Final merit rating =

10

DW10C TESTING – ECOCELAN™

Merit Rating = 10

DW10C ENGINE TESTING – ECOCLEAN™ RATING

Data below demonstrates excellent performance of ECOCLEAN™ technology

DW10C test responds well to different additive levels

In the absence of industry pass/fail criteria, good correlation of field and engine data provides us with confidence to suggest appropriate level of performance

Candidate Merit

RF-79 + 0.5ppm Na + 10 mg/kg DDSA 4

RF-79 + 0.5ppm Na + 10 mg/kg DDSA + ECOCLEAN™technology

10

INJECTOR STICKING

Vehicle Testing

VEHICLE TESTING – INJECTOR STICKING

Using EN590 fuel (B7) with no fuel adulteration, matched pair vehicle study performed

One base fuel vehicle

One additive vehicle – ECOCLEAN®

After 15,000km, base vehicle would not start after reports of rough running

Additised vehicle continued running normally for >15,000km

VEHICLE TESTING – INJECTOR STICKING

Ball bearing

in bucket Main shaft

Nozzle stuck

in needle

VEHICLE TESTING – INJECTOR STICKING

Injectors sent to a specialist test facility for evaluation

Additive injector – Classed ‘As good as new’

Base fuel injector observations

Ball bearing stuck in bucket – normally separated easily from injector

Main shaft – abnormal oily film on surface, fuel related

Needle would not come free from nozzle. High pressure airline and ultrasonic bath could not separate components. Classed as failed components. Problem in exact position as proposed CEC test.

SUMMARY

IDID performance is becoming a requirement for many fuel marketers in Europe

Na/Acid contamination can still occur so consumers do need to be protected via suitable fuel additive use

No official pass/fail criteria set by CEC but the following recommended

Regular grades should achieve 8-9 merits

Premium grades should achieve 9-10 merits

The above targets consider 1 merit reproducibility of test