Multiple Fuel Injector Failures

[Batman0424]

Hi all,

Hoping to gather some insight here.

Back story, I have been experiencing sputtering / misfires (initially without codes and more recently with misfire codes). On two occasions the car through a CEL and EPC where the EPC would not go away after clearing codes. First time, cylinder 1 injector failed (a few months ago). Second time, cylinder 5 injector failed (two weeks ago).

For a while now, I have suspected that the misfires / sputtering could be cat related, but I am not certain of this anymore (will need to scope the cats).

Has anyone else experienced multiple injector failures? Any thoughts as to what could have caused these to fail (any underlying issue that needs to be fixed)?

[infinkc]

First i have relly heard of failed fuel injectors on the b8s4. Was your car part of the fuel rail recall? Thinking your issue is being caused by something else, since you should be still under warranty did the dealer say anything else?

[Batman0424]

First i have relly heard of failed fuel injectors on the b8s4. Was your car part of the fuel rail recall? Thinking your issue is being caused by something else, since you should be still under warranty did the dealer say anything else?

It is not part of the recall (that I am aware of anyway).

I brought the car to a buddy of mine (well experienced Audi mechanic) who has a shop as the car is tuned.

[andthen]

When I had an injector actually fail it was still working but causing an imbalanced fuel trim on one bank.

When I had multiple misfires on one bank it was a bad cat.


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[Batman0424]

When I had an injector actually fail it was still working but causing an imbalanced fuel trim on one bank.

When I had multiple misfires on one bank it was a bad cat.


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The only other misfires that occurred was approx 2-3 week before this last injector failure. Those misfires were cylinder 1 and 6, which pointed a bit more towards possible cat issues. This issue has been bugging me for months now.

[andthen]

How many miles do you have?
Could be aging coil packs.

What pulley set up, if any?
Could be plug gap at higher boost.

1 and 6 are on different banks. Both cats seems unlikely but not it's not impossible. When my cat went it was all cylinders on bank misfiring at higher RPMs.




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[skiracerblah]

Could some gunk be clogging the injectors? Does the fuel pump have a filter have a filter attached to it? If so, maybe look at the filter to see how dirty it is.

[Batman0424]

I have about 16k miles and am running a dual pulley setup.

I've had all coils and plugs replaced. I thought maybe gapping too, but this happened when i reverted back to the Stg 1 tune as well.

I don't see why there wouldn't be a fuel filter, but not sure where this is located. Could pull this out to see if that is damaged. Maybe some material made it passed and is clogging injectors.


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[BlownOne]

No way that your fuel filter is clogged at 16k miles...I just changed mine at 49k and it didn't look too bad but I am running an e85 blend. If you can flash from home, go back to the stock file and see if the problem persists.

[Batman0424]

No way that your fuel filter is clogged at 16k miles...I just changed mine at 49k and it didn't look too bad but I am running an e85 blend. If you can flash from home, go back to the stock file and see if the problem persists.

I can and I've done that as well. The sputtering would occur if I was cruising at higher RPMs (any gear) and started to roll on the throttle (steady increased pressure, not mashing the pedal) to redline. Most times I would get no codes, but on 3 occasions I did and 2 of those times an injector was bad.

What I don't know is what caused the injector to go bad or if the injector issue isn't related (I doubt this - simplest solution is usually correct, in theory).


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[amz]

First i have relly heard of failed fuel injectors on the b8s4. Was your car part of the fuel rail recall? Thinking your issue is being caused by something else, since you should be still under warranty did the dealer say anything else?

I've gone through 10 since I bought the car in December 2014...local dealer admits they're a crappy design. Only use top-tier Shell 91 gas and I beat on the car during the summer; so far injectors only seem to fail in the dead of winter (both times I've gotten a CEL for multiple cylinders being rich in late Feb...)

[Batman0424]

I've gone through 10 since I bought the car in December 2014...local dealer admits they're a crappy design. Only use top-tier Shell 91 gas and I beat on the car during the summer; so far injectors only seem to fail in the dead of winter (both times I've gotten a CEL for multiple cylinders being rich in late Feb...)

Damn! So I shouldn't be surprised.

Did you have any sputtering / misfires without CEL?


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[miztahsparklez]

I'm just wondering if mine keep dumping excess fuel and blowing my cats. My fuel consumption is awful. My mpg is in the teens.


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[Batman0424]

I'm just wondering if mine keep dumping excess fuel and blowing my cats. My fuel consumption is awful. My mpg is in the teens.


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My MPG is too unless I drive very reserved.


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[skiracerblah]

No way that your fuel filter is clogged at 16k miles...I just changed mine at 49k and it didn't look too bad but I am running an e85 blend. If you can flash from home, go back to the stock file and see if the problem persists.

E85 makes a great fuel system cleaner. Problem, it works to well. if you have any exisiting gunk in your fuel tank , the E85 wil loosen it and it can potentially clog up in the lines/rail/injectors. I know this has happened many times in the Evo/Sti World, especially those with a lot of miles on it and they switch to E85...

[SwankP3RF3ct10n]

These engines are direct injection, which means the injector heads are not protected from combustion chamber pressures like traditional injectors are by the valves. So am I out of my mind to think that if you've got a shitty tune or something else is causing major combustion pressure to happen, like detonation, etc., eventually the injectors themselves could also be damaged in the same way that a spark plug does during such events? An injector is a precision components and any damage to it could easily damage it more so that something like a spark plug. Maybe I'm wrong, please correct me.

[BlownOne]

E85 makes a great fuel system cleaner. Problem, it works to well. if you have any exisiting gunk in your fuel tank , the E85 wil loosen it and it can potentially clog up in the lines/rail/injectors. I know this has happened many times in the Evo/Sti World, especially those with a lot of miles on it and they switch to E85...

Very true...I remeber when we all first started running e85 in our evo8's and a few high mileage cars had the black gunk on the injector tip problem. Solution was to run gasoline every 5 tanks or so, but nobody wanted to switch to a pump gas map lol.

[BlownOne]

I can and I've done that as well. The sputtering would occur if I was cruising at higher RPMs (any gear) and started to roll on the throttle (steady increased pressure, not mashing the pedal) to redline. Most times I would get no codes, but on 3 occasions I did and 2 of those times an injector was bad.

What I don't know is what caused the injector to go bad or if the injector issue isn't related (I doubt this - simplest solution is usually correct, in theory).


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Ahhhh shit well that sucks. I would say pull the injectors (if you can), mark what cylinder each one came from and take a good look at them all to see if anything stands out on the ones that have given you a code. If they are clogged or gunked up you can soak them in e85, agitate them, soak them in gasoline, agitate and see if that helps.

[abamfo]

Not sure if this will help but why don't you try run the VW fuel additive stuff which cleans the injectors. I had heaps of black carbon sooty crap come out of my exhaust after I used it. Just a thought if your injectors are clogged with something and cheaper than replacing them in the first instance, that's for sure!

There is a TSB out there which says to use them for suspected dirty injectors. Costs like $10 from any Audi parts department

[Batman0424]

Thanks all for the advice. I do run the tank closer to E than I would like (I try to get over to a prefer station to fill, but I'm not always close to one).

I'll try the additive first and then pull all the remaining injectors to see if any are damaged / look different. Maybe running the tank low has caused some debris to clog these injectors.

I'm also going to have the shop look at the cats through the O2 sensor hole (thanks abamfo).


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[skiptowncat]

Check the condition of the injector seals as well, this can cause spluttering.

[Batman0424]

Check the condition of the injector seals as well, this can cause spluttering.

Thank you, I will do this as well.


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[audistealth]

As far as gas additives go, I periodically use Chevron Techron with a fill up.

[abamfo]

Thanks all for the advice. I do run the tank closer to E than I would like (I try to get over to a prefer station to fill, but I'm not always close to one).

I'll try the additive first and then pull all the remaining injectors to see if any are damaged / look different. Maybe running the tank low has caused some debris to clog these injectors.

I'm also going to have the shop look at the cats through the O2 sensor hole (thanks abamfo).


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Also it might be worth checking injector flow rates on VCDS, jran explains the figures in his logging lesson post... Just check those cylinders versus the others, I guess... physically checking injectors does take some time with SC coming off, etc.

Very bad cats will look like this through the o2 sensor hole (this isn't mine, funnily enough my cats look fine)

[Batman0424]

Also it might be worth checking injector flow rates on VCDS, jran explains the figures in his logging lesson post... Just check those cylinders versus the others, I guess... physically checking injectors does take some time with SC coming off, etc.

Very bad cats will look like this through the o2 sensor hole (this isn't mine, funnily enough my cats look fine)

I'll do that next and send this photo to my shop.


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[kcobourn]

During this morning's cold start I threw a misfire across cylinders 1-3. Assuming it's related to running E85 at 55k? I filled with shell 93 and getting it looked at by my shop just in case.

Update: hooked up VAG-COM and figured out my E85 mix was likely the cause. Misfires were all banks and the Oriely Bosch unit didn't get all the data. All misfires are cold starts below 1500 RPM & 40 degree Celsius. The lesson? If you run E85 you really need to log to confirm the right mix!! Lesson learned.

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[skiracerblah]

Thanks all for the advice. I do run the tank closer to E than I would like (I try to get over to a prefer station to fill, but I'm not always close to one).

I'll try the additive first and then pull all the remaining injectors to see if any are damaged / look different. Maybe running the tank low has caused some debris to clog these injectors.

I'm also going to have the shop look at the cats through the O2 sensor hole (thanks abamfo).


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I've used this fuel system cleaner BG 44K in the past multiple times and this stuff rocks. Its not cheap at around $20/bottle...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[mrmomo313]

I can and I've done that as well. The sputtering would occur if I was cruising at higher RPMs (any gear) and started to roll on the throttle (steady increased pressure, not mashing the pedal) to redline. Most times I would get no codes, but on 3 occasions I did and 2 of those times an injector was bad.

What I don't know is what caused the injector to go bad or if the injector issue isn't related (I doubt this - simplest solution is usually correct, in theory).


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What codes did you see on those 3 occasions? Were those the misfire codes you mentioned or did it specifically throw a code for the injectors? Wondering how you diagnosed the injectors failing.

I do find it very odd that your low mileage 15 is having injector issues. What kind of gas (brands/octane) do you usually run in the car?

[Batman0424]

What codes did you see on those 3 occasions? Were those the misfire codes you mentioned or did it specifically throw a code for the injectors? Wondering how you diagnosed the injectors failing.

I do find it very odd that your low mileage 15 is having injector issues. What kind of gas (brands/octane) do you usually run in the car?

The only codes were for misfires. The shop diagnosed the injector after doing compression checks and (previously) changing plugs and coils.

I usually use Citgo, She'll or Sunoco. In desperation, I stop at a Speedway (not ideal, but never had issues before) and always 93.


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