رقم العضوية : 33656
تاريخ التسجيل : 22Feb2009
المشاركات : 20,472
النوع : ذكر
الاقامة : مصر الجديدة
السيارة: Fiat 128
السيارة[2]: Fiat Linea
دراجة بخارية: no
الحالة :
رقم العضوية : 85958
تاريخ التسجيل : 16Jan2011
المشاركات : 3,132
النوع : ذكر
الاقامة : Egypt - Faisl
السيارة: Verna , 1.5 , M/T
السيارة[2]: Toyota Yaris , 1.3 , A/T
دراجة بخارية: لا يوجد
الحالة :
رقم العضوية : 33383
تاريخ التسجيل : 18Feb2009
المشاركات : 2,143
النوع : ذكر
الاقامة : Giza
السيارة: Fiat 131
السيارة[2]: VW Polo
دراجة بخارية: ...........
الحالة :
بقالي فتره مش لاقي بنزين 80 ولا 90 ف كنت بفول 92
بعد العك بتوع اليومين الي فاتو اكيد ال ecu اتروش d:
ماحستش اني حطيت بنزين اوكتان اعلى . بالعكس لبست تفويله مغشوشه نصها ميه بوظتلي الكربراتير
الاسبوع الي فات حطيت صفيحه 95 بس فرق جامد ف السحب و الماتور بقى صوته هادي!
ف اعتقد ال95 مش مغشوش بس مش موجود
م. سعدالدين مصطفى
Follow me on Twitter @Saadelden
http://www.nilemotors.net/Nile/67592-131.html
رقم العضوية : 93462
تاريخ التسجيل : 04Apr2011
المشاركات : 1,484
النوع : ذكر
الاقامة : alexandria
السيارة[2]: spark
دراجة بخارية: no
الحالة :
The fuel injector, though small, is a very solidly constructed fuel system component part. It has to be, considering the extreme heat environment where the injector is located. As mentioned on another page of this site, for a daily driver vehicle, (12,000miles/year), each injector will cycle approximately 18,000,000 times! Recall, that the Jaguar V12 HE injector fires twice per engine cycle. So that at 2,000 RPM, the injector has operated 2,000 times. That's 33.3 times/second. An extraordinary duty demand indeed! If you consider your personal vehicle, and your driving habits, you can get an estimate of the service duty thru which they have been subjected.
Due to the heat environment, the extraordinary duty demands, and the fact that, after all, the fuel injector is a mechanical and electrical part, the fact is, an injector is subject to problems, faults and failure. Let's take a look at the potential fuel injector problems and failure modes of an injector, the possible causes of each failure mode, and the potential resulting effect on engine performance.
FAILURE 1...Unburned fuel additives are baked on the injector pintle and orifice altering flow volume, altering fuel spray pattern.
CAUSE OF FAILURE 1...normal use of vehicle but lack of fuel system maintenance; after engine shutdown "heatsink" resulting in higher "baking" temperatures for unburned fuel and/or fuel additives remaining on injector; overheating of engine (and the injectors) from faulty cooling system, improper engine timing, contaminated fuel, incorrect fuel octane, vacuum leaks.
EFFECTS OF FAILURE 1...lack of engine power, sluggish pickup/performance, poor fuel econony, leaking fuel injector, potential for engine overheating, O2 sensor damage, remaining injectors/cylinders are overfueled to compensate for underfueled injectors/cylinders as the "closed loop" O2 system attempts to maintain stoiciometric ratio.
FAILURE 2...Injector filters become clogged.
CAUSE OF FAILURE 2..."Foreign particles" in fuel tank(s) or fuel lines, or fuel rail. Foreign particles in almost all instances, will be rust. Larger rust particles may be collected within the injector filter, or the fuel filter, and reduce fuel flow. Microscopic rust particles may also pass thru the injector filter, and cause the spray pattern to alter, fuel flow to alter, and/or the injector pintle to not seat properly. This is a common problem on vehicles that have sat unattended, or suffered from lack of routine maintenance. Incorrect fuel tank fuel filter; holes/tears in fuel tank fuel filter; breakdown/degradation of interior wall of fuel supply line; breakdown/degradation of interior wall of fuel injector hose, and rust in the fuel rail.
EFFECTS OF FAILURE 2...the injectors leak at the pintle and/or the spray pattern is altered, and/or the fuel flow is altered. Lack of engine power from underfueling; potential for engine overheating; remaining injectors/cylinders are overfueled to compensate for underfueled injectors/cylinders as the "closed loop" O2 system attempts to maintain stoiciometric ratio.
FAILURE 3...Injector windings don't lift pintle, seized pintle, or slow pintle cycling.
CAUSE OF FAILURE 3...injector coil windings overheated from cooling system failure or ignition failure, with windings losing their magnetic performance; open (broken) windings; shorted (grounded) windings; seized pintle from internal injector corrosion (engine has set too long without running causing the injector to rust internally, petrol contamination with water, or cycling of injector without fuel flow to act as cooling agent and lubricant).
EFFECTS OF FAILURE 3...(A) If injector pintle is "off" the seat...overfueling of affected cylinder with resultant underfueling of remaining cylinders within "closed loop", poor engine performance, poor fuel economy, possible O2 sensor damage, potential engine overheating and engine damage, hard or no start, fuel leaks after shutdown. (B)If injector pintle is "on" the seat...underfueling/no fueling of affected cylinder with resultant overfueling of remaining cylinders with "closed loop" system, poor engine performance, poor fuel economy, O2 sensor damage, engine/piston/ring damage.
FAILURE 4...Body or mechanical joint leak in injector body.
CAUSE OF FAILURE 4...Defective manufacturing and testing, overheating of injector from cooling system failure, ignition system failure, incorrect timing, improper "handling" during installation/removal/storage/shipping, etc.
EFFECT OF FAILURE 4...High potential for engine fuel fire (dependent on location of leak), poor engine performance, poor fuel economy, potential for engine damage.
FAILURE 5...injector pintle doesn't fully seat on orifice.
CAUSE OF FAILURE 5...fuel additives "baked" on pintle or orifice, weak injector return spring, rust/corrosion internal to injector body.
EFFECT OF FAILURE 5...leaking fuel injector, after shutdown fuel leak in affected cylinder (causing hard start), overfueling of affected cylinder with resultant underfueling of remaining cylinders in the "closed loop" system, potential for damage to O2 sensor or "cats".
FAILURE 6...external electrical connectors broke/corroded.
CAUSE OF FAILURE 6...mishandling during installation/removal/testing, water/moisture leaking past injector plug connector, inadequate vehicle maintenance, improper storage.
EFFECTS OF FAILURE 6...no firing, intermittant firing, or weak firing of injector due to poor electrical conductivity , poor engine performance, poor fuel economy. engine overheating, potential engine damage, overfueling of other cylinders as 02 sensor reads excess 02 in exhaust and adjusts "rich" to compensate.
"CLOSED LOOP" SYSTEM note...When the engine management system is in this mode, the 02 sensor(s) are monitoring O2 exhaust gas emissions and feeding signals to the ECU. The ECU will interpret the signal(s) and adjust injector "pulse width", within a range, attempting to keep the air/fuel mixture at the proper ratio, such that O2 (and therefor exhaust emission levels) are within specifications. Some engine failure conditions cannot be fully compensated for and the engine will remain in a "less than satisfactory" level of performance. If the ECU can return the air/fuel ratio back to a "satisfactory" level, it must be remembered that there is still a failure condition present, which required correction. The ECU has merely "balanced" out by overfueling or underfueling cylinders (injectors), to achieve an acceptable exhaust emission reading. Fuel consumption will still be higher than spec, and performance will still be low.
"OPEN LOOP" SYSTEM note....This is repeated elsewhere on the site due to its importance! In "open loop" operation, the ECU is not monitoring the presence of O2 in the exhaust stream. The engine goes "open loop" at WOT (wide open throttle) and the ECU fuel adjustment goes rich +/- 10 %. This keeps HP up, and engine temperatures down. Injector flows that may have been adjusted for low flows in "closed loop", will STILL remain underflow...even with the WOT fuel addition. Not a good situation at WOT.
Fuel injectors are made to operate thru several billion cycles. Rarely do they fail mechanically or electrically. The most common failure mode is...they get fouled from burned on fuel and fuel additives, causing poor spray pattern, poor atomization, poor vaporization of fuel if the fuel does not hit the "target zone" on the back of the intake valve, and reduction in fuel delivery. The ECU can be compared to the human brain...the ECU does the thinking, signaling the injector on when to fire, and how long the pulse duration should be. The fuel injector can be compared to the heart...the injector does the pumping. It has no brain and only responds based upon ECU input. If an injector, or injectors, are not on spec, the ECU will attempt to correct flow delivery via altering injector pulse, but it cannot correct the faulty injector(s). Injectors need to be clean for optimal system performance.
DarkMagician
رقم العضوية : 36370
تاريخ التسجيل : 23Mar2009
المشاركات : 802
النوع : ذكر
الاقامة : MISR EL MAHROUSA
السيارة: بأفكر في بسكلتة
السيارة[2]: fiat siena
دراجة بخارية: لا توجد
الحالة :
Eng.Ahmed Yousef
رقم العضوية : 119672
تاريخ التسجيل : 27Jan2012
المشاركات : 6,807
النوع : ذكر
الاقامة : النزهه الجديدة
السيارة: اتباعت
السيارة[2]: lanos 1.5 16 v
دراجة بخارية: لا يوجد
الحالة :
انا زهقت بقيت راكب مرجيحه والعربيه بتقطع تتكتم وفجاء تسلك كأنى دوست فرامل
رقم العضوية : 21857
تاريخ التسجيل : 11Oct2008
المشاركات : 572
النوع : ذكر
الاقامة : القاهرة
السيارة: لا يوجد
السيارة[2]: Lancer 1.6 auto 2013
دراجة بخارية: لا
الحالة :
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