Titua1915

I am looking for a manual or instructions on DIY to replace all 8x fuel injectors on Audi Q7 2007 4.2

xThinG

Titua1915

it got 160k miles, do you have a manual or diy instructions for it? and is it easy to do a light carbon cleaning while replacing injectors? meaning is it through same route?

xThinG

No i dont have a manual,but if u are purchasing them they must be with manual with instructions on how to replace them,try to clean with the air compressor why the carbon cleaning?
before you replace all the 8 injectors make sure that the pump is good and not transferring metal fillings so it's not gonna wreck the whole injectors

Titua1915

I mean i heard when the high pressure fuel pumps go bad they will give you an error code, i getting multiple misfires, and cat codes. I get cold hard starts with check engine blinking. I have done spark plugs, coils all oem, only thing left is the injectors and then replace the cat or o2 spacer as i know the fuel from injectors messed up cats

Titua1915

I am just getting multiple cylinder misfires after trying coils and spark plugs with no success only thing left is injectors. and of course now the cat is bad.

Up-it

Hey mate. Yes the fuel injector are quiet easy to replace but getting to them is the hard part. There is a bunch of pics/ videos on how to remove tve 4.2fsi intake group on the internet as all 4.2 fsi engines are the same accross all audi models. I have removed and replaced mine 5 times and each time is becoming a faster and faster experience.
the last i did mine was for also the “carbon build up removal”. Once again plenty of write ups from audi A8 / B7 owners.
I received far better engine response from cleaning out my intake ports but I managed to use a drill and wire brushes to clean them. Very messy job but great results. Also some people sand blast their intakes with nutshell and works great also.
the 4.2 fuel pumps are hard to make metal as their just a small spring and plunger with the camshaft side all in the engine oil & not in the fuel.
If you are unable to locate a 4.2fsi w/shop manual the next best thing would be to spend 1 hr on google reading & looking from others experiences to get a taste of what is going to be involved mate.
All the best.

Titua1915

THANKS FOR YOUR TIME UP-IT, I AM CONSIDERING REPLACING ALL 8 WITH RECONDITIONED ONES FROM JHM SET OF 8X FOR $480. HOPEFULLY THIS FIXES MY HARD STARTS AT TIMES WITH MISFIRES. I MEAN I HAVE CHANGED ALL COILS AND SPARK PLUGS WITH OEM AND NOTHING HAS CHANGED. IS THIS COMMON FOR TO GO BAD ON THIS Q7 4.2 FSI ENGINE? I HAVE READ IT CAN BE HIGH PRESSURE FUEL PUMP CAUSING MISFIRES AND HARD STARTS BUT I AM NOT GETTING ANY FUEL PUMP RELATED CODE. ALSO HARD STARTS IS NOT ALWAYS. ATTACHED IS THE VAG READING.

10 Faults Found:
000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 -
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 6
Reset counter: 255
Mileage: 276560 km
Time Indication: 0
Date: 2017.12.07
Time: 20:38:34

Freeze Frame:
RPM: 654 /min
Load: 26.7 %
Speed: 0.0 km/h
Temperature: 70.0°C
Temperature: 53.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 13.462 V

000772 - 4
P0304 - 008 - Misfire Detected
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 6
Reset counter: 255
Mileage: 276560 km
Time Indication: 0
Date: 2017.12.07
Time: 20:38:34

001110 - EVAP System
P0456 - 001 - Very Small Leak Detected - MIL ON
Freeze Frame:
Fault Status: 11100001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 276562 km
Time Indication: 0
Date: 2017.12.08
Time: 07:26:59

Freeze Frame:
RPM: 1973 /min
Load: 50.6 %
Speed: 72.0 km/h
Temperature: 66.0°C
Temperature: 7.0°C
Absolute Pres.: 1010.0 mbar
Voltage: 13.970 V

000769 - 1
P0301 - 008 - Misfire Detected
Freeze Frame:
Fault Status: 11100001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 276562 km
Time Indication: 0
Date: 2017.12.08
Time: 07:26:59

000773 - 5
P0305 - 008 - Misfire Detected
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 276576 km
Time Indication: 0
Date: 2017.12.08
Time: 16:24:23

Freeze Frame:
RPM: 701 /min
Load: 22.7 %
Speed: 0.0 km/h
Temperature: 42.0°C
Temperature: 33.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.462 V

000775 - 7
P0307 - 008 - Misfire Detected - Intermittent
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 276576 km
Time Indication: 0
Date: 2017.12.08
Time: 16:24:23

000770 - 2
P0302 - 008 - Misfire Detected
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 276576 km
Time Indication: 0
Date: 2017.12.08
Time: 16:24:23

Freeze Frame:
RPM: 701 /min
Load: 22.7 %
Speed: 0.0 km/h
Temperature: 42.0°C
Temperature: 33.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.462 V

001057 - Warm Up Catalyst; Bank 1
P0421 - 002 - Efficiency Below Threshold - MIL ON
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 276576 km
Time Indication: 0
Date: 2017.12.08
Time: 16:24:23

001073 - Warm Up Catalyst; Bank 2
P0431 - 002 - Efficiency Below Threshold - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 276627 km
Time Indication: 0
Date: 2017.12.09
Time: 22:18:51

Freeze Frame:
RPM: 1855 /min
Load: 40.4 %
Speed: 68.0 km/h
Temperature: 84.0°C
Temperature: 15.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.462 V

000776 - Cylinder 8
P0308 - 008 - Misfire Detected
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 276627 km
Time Indication: 0
Date: 2017.12.09
Time: 22:18:51

Readiness: 0000 1000

Up-it

Hey mate, is the vcds report frim after you have cleared codes prior to around 7&8 december as per the dates of the fault codes, just because many of the fault frequencies are only 1 -2 occurrences?? On start up does the engine sound like it is actually missing/ running rough and then clears up after say 2 mins idiling?
there are only by memory 4 knock sensors under the intake that would pick up bad detonation but your injector coil wires are the ones that sense engine miss fire. The red harness that clips onto the coils are somewhat prone to cracking the wires around the plastic clip causing miss fires on earlier 2004 - 2006 which is why they upgraded the harness to include the 2 screw into the side of the rocker cover. Worth just checking the red harness but your fault codes show all 8 as a missfire.
highly unlikely injectors if the engine begins to run smoothly after several minutes.??

on start up the change over valves on the intake act like a choke system. The electric valves are under the “v8-4.2” plastic cover. When started these valves will move the silver linkages to a semi closed state until the engine warms and then allows more air into the intake ports. If one of your valves is cactus or sticking it will cause one cylincer head to run rough and the other smooth but your o2 sensors will have a melt down because they are reading incorrectly to what the computer wants.

Have a look on next start up and watch the linkages and ensure they open and close as normal all within about 4 mins as you will hear the idle drop. let is know how you go with it bud

Titua1915

I've had these multiple cylinder misfires since July 2017, I always reset it through vcds but after a day or two it comes back. I have a second Audi which is an a6 c6 model 3.2 and i have a code relating to that in which you mentioned with intake flap motors being stuck open and to be honest on that one i have no misfires or issues but the check engine light for the intake flap motors being stuck open. But on this Q7 4.2L my boys cousin who works at the dealer plugged in the system they use there and it had an error showing clogged injectors. I lost contact with him but it did mention something about the injectors on the screen which i saw with my own eyes. I have done everything from coils, spark plugs and fuel injector cleaner and still nothing. I've read somewhere on b8 forum with the 4.2 engine where audi owner where facing same issue where everything was replaced and nothing fixed it until replacing 8x injectors, and were also faced with changing to new cat because the fuel messed up the cats. Only thing they didnt mention were hard starts. sometime engine will crank and rev up under 1000rpm and then engine died. I would have to recrank and then will fire right up.