[philtr]

I'm still rocking index 1 injectors and they seem to be working reasonably well but I'm also noticing occasional stumbling and roughness at idle even with walnut blasting and new plugs/coils so I think the writing is on the wall. Also, seems prudent to replace them before cranking up the boost with upgraded turbos

With that said it looks like I missed the boat on reasonably priced index 12 injectors. I've seen some good advice here on the options from places like Advance Auto but these "standard intermotor" FJ1284 injectors are sold out pretty much everywhere. I see one reputable place has them for $108/ea but again out of stock and over a month to get in (going to call them tomorrow). So a few questions:

Anyone know of sources for reasonably priced injectors that are in stock?

Have the intermotor and other differently branded injectors that aren't refurbished truly verified to be OEM or at least fully equivalent to index 12's?

Finally, any crazy people that would vote to keep going with my index 1's until there is an obvious problem beyond occasional idle roughness without fault codes?

Thanks!

[rediahad]

I just went through the same thing last month. I wound up wasting two weeks looking for a better price then went through fcp euro. No ome else has them

[feuer]

Keep the index #1

[philtr]

Originally Posted by feuer

Keep the index #1

My bank account likes this advice. Do you mind sharing your logic behind it? My main fear of continuing with the index 1's is blowing the motor either through oil dilution if an injector develops a leak or running lean when turning up the boost if an injector is partially clogged or has other issues. Are these fears not well founded? Thanks.

[feuer]

Originally Posted by philtr

My bank account likes this advice. Do you mind sharing your logic behind it? My main fear of continuing with the index 1's is blowing the motor either through oil dilution if an injector develops a leak or running lean when turning up the boost if an injector is partially clogged or has other issues. Are these fears not well founded? Thanks.

I work on these and don't see Index #1 fail often. Send oil sample for analysis. That will tell you if injectors are leaking. Running lean usually is from different reasons, like tune, vacuum leak, O2 sensors, weak fuel pumps....To diagnose that you need to do some logs.

[srey]

Originally Posted by feuer

I work on these and don't see Index #1 fail often. Send oil sample for analysis. That will tell you if injectors are leaking. Running lean usually is from different reasons, like tune, vacuum leak, O2 sensors, weak fuel pumps....To diagnose that you need to do some logs.

Does it matter how recently the car has operated in sending an oil sample out? For example, my car has been parked since November. If I wanted to get the most accurate results from an oil analysis, particularly regarding fuel content, should I wait until Spring when I start dailying it again?

[philtr]

Originally Posted by feuer

I work on these and don't see Index #1 fail often. Send oil sample for analysis. That will tell you if injectors are leaking. Running lean usually is from different reasons, like tune, vacuum leak, O2 sensors, weak fuel pumps....To diagnose that you need to do some logs.

Yes, the oil analysis is a good idea. So far I haven't noticed obvious symptoms of a leaky injector but I guess when small it's probably hard to detect.

The running lean worry would be from one injector in a bank not providing enough fuel but the overall AFR from the bank not being so far out to shut things down so to speak causing a dangerously lean condition in one cylinder. I've already done some logging and don't see anything alarming with fuel pressures or AFR's on the larger scale of each bank.

[feuer]

Originally Posted by srey

Does it matter how recently the car has operated in sending an oil sample out? For example, my car has been parked since November. If I wanted to get the most accurate results from an oil analysis, particularly regarding fuel content, should I wait until Spring when I start dailying it again?

Contact the oil lab of choice and ask for instructions but I believe they recommend draining the oil and getting a sample from engine that was at operating temperature.

[feuer]

Originally Posted by philtr

Yes, the oil analysis is a good idea. So far I haven't noticed obvious symptoms of a leaky injector but I guess when small it's probably hard to detect.

The running lean worry would be from one injector in a bank not providing enough fuel but the overall AFR from the bank not being so far out to shut things down so to speak causing a dangerously lean condition in one cylinder. I've already done some logging and don't see anything alarming with fuel pressures or AFR's on the larger scale of each bank.

So you have lean condition fault codes or? DME has control of individual injector thus the reason for injector coding. If AFR on particular bank is OK why are you worryng? Post logs.

Originally Posted by srey

If I wanted to get the most accurate results from an oil analysis, particularly regarding fuel content, should I wait until Spring when I start dailying it again?

What's the point of testing for fuel contamination if you're going to bring the oil temps up enough to burn any possible fuel out of it..??

If you want an accurate representation of whether or not there is fuel in the oil due to leaky injector, then yes, you want to measure it after the car has been sitting a long time...the longer the better.

[feuer]

Originally Posted by FCobra94

What's the point of testing for fuel contamination if you're going to bring the oil temps up enough to burn any possible fuel out of it..??

If you want an accurate representation of whether or not there is fuel in the oil due to leaky injector, then yes, you want to measure it after the car has been sitting a long time...the longer the better.

This make a lot of sense. It would be more accurate to send a oil sample from oil that set.

[fozzydj]

Index 12's over here (UK) are £102 each from dealership. Not sure on what shipping cost would be across the pond?

I bought 6 for £612/$778

Id be happy to help if required.

[Bimmer_Engineer]

Originally Posted by fozzydj

Index 12's over here (UK) are £102 each from dealership. Not sure on what shipping cost would be across the pond?

I bought 6 for £612/$778

Id be happy to help if required.

Are those lifetime warranty? For reference I paid about $1200 for a set of index 12s with lifetime warranty in August...

[fozzydj]

Originally Posted by Bimmer_Engineer

Are those lifetime warranty? For reference I paid about $1200 for a set of index 12s with lifetime warranty in August...

Standard BMW 2 year warranty. Rumours are they are pretty solid the index 12's though

[marconi118]

Originally Posted by fozzydj

Index 12's over here (UK) are £102 each from dealership. Not sure on what shipping cost would be across the pond?

I bought 6 for £612/$778

Id be happy to help if required.

where did you get them so cheap?

[fozzydj]

Originally Posted by marconi118

where did you get them so cheap?

Dealership

[philtr]

Originally Posted by fozzydj

Index 12's over here (UK) are £102 each from dealership. Not sure on what shipping cost would be across the pond?

I bought 6 for £612/$778

Id be happy to help if required.

Thanks Fozzy! The best price here in the states for genuine index 12's is $1200 so that's certainly much better. I'd be tempted to take you up on your offer if we could figure out the international shipping easily.

[philtr]

Originally Posted by feuer

So you have lean condition fault codes or? DME has control of individual injector thus the reason for injector coding. If AFR on particular bank is OK why are you worryng? Post logs.

No lean or injector related fault codes. So, what would happen if one injector in a bank was not delivering enough fuel for whatever reason? My understanding is that the O2 sensor for that bank would see a somewhat lean condition and the DME would richen the whole bank which means 2 of the cylinders would be overly rich and 1 still potentially too lean. Possibly there might be misfire faults and timing corrections as well but might depend on the situation. Am I misunderstanding this?

[feuer]

Originally Posted by philtr

No lean or injector related fault codes. So, what would happen if one injector in a bank was not delivering enough fuel for whatever reason? My understanding is that the O2 sensor for that bank would see a somewhat lean condition and the DME would richen the whole bank which means 2 of the cylinders would be overly rich and 1 still potentially too lean. Possibly there might be misfire faults and timing corrections as well but might depend on the situation. Am I misunderstanding this?

My understanding is that DME can manipulate individual injector thus the need for injector coding.

[dpaul]

Originally Posted by philtr

No lean or injector related fault codes. So, what would happen if one injector in a bank was not delivering enough fuel for whatever reason? My understanding is that the O2 sensor for that bank would see a somewhat lean condition and the DME would richen the whole bank which means 2 of the cylinders would be overly rich and 1 still potentially too lean. Possibly there might be misfire faults and timing corrections as well but might depend on the situation. Am I misunderstanding this?

That sounds correct. The DME cannot know the AFR for a given cylinder, only the average for the bank of three. A bad injector might result in a misfire which of course the DME can detect on an individual basis.

[philtr]

Originally Posted by dpaul

That sounds correct. The DME cannot know the AFR for a given cylinder, only the average for the bank of three. A bad injector might result in a misfire which of course the DME can detect on an individual basis.

Thanks, glad my line of thinking computes with someone else as well. I've never had misfire codes so I hope that's a sign the old index 1's are still metering the correct fuel under load. I do see some random timing corrections however that vary by cylinder.

[philtr]

Originally Posted by feuer

My understanding is that DME can manipulate individual injector thus the need for injector coding.

Yes, I agree that the DME has the ability to control individual injectors. I just don't see how it fine tunes AFR on each cylinder since there are only 2 O2 sensors. Even the fuel trims are divided into bank 1 and 2 which likely confirms it meters fuel to each bank based on that O2 sensor and other feedback. I wonder in what cases it changes individual injector metering?