Dealer replaced injectors and water pump and now power delivery and shifts are awful.

[ManiacGT]

So late 2017 my car developed a cold start misfire. I booked the car into the local dealership.

On the way to the dealership the car overheated (amber warning) and as I rolled into the dealer car park I got a red warning to stop the car, which I did.

They diagnosed water pump failure and the misfire as faulty injectors.

Both were replaced and the car returned to me.

The following day under cold start I noticed the car felt lazy and I put it down to perhaps a reset of some adaptations by the dealer.

Several weeks later it got no better and then followed several months of back and forth to the dealer for them to ultimately give up as they could find no fault codes nor detect or understand what I was telling them.

Essentially the cars power could feel sloppy and lazy one day then fairly normal the next.

However DCT shifts were snatchy (used to be smooth) and power drops away after shifts before recovering seconds later. It’s unpredictable and unnerving to drive.

I took the plunge to apply MHD stage 1 and this allowed me to play with wastgate settings etc and putting the setting into low lag improved this snatchy and power drop off but it didn’t make the car as it used to be.

A number of forums are telling me different things about the MHD logs I’m pulling but no one has any idea of the cause.

I took a plunge to replace turbo solenoids but that made no difference.

Vac pipes seem to hold vacuum.

I’ve tested diverter valves and they seem ok.

A bit lost now...

 

[RSL]

Why would they be happening on an otherwise stock car though?

For those that don’t know, the DSC runs the e diff and still remains effective with TC set to dynamic. I think it’s still engaged when it’s totally off as well.

Yeah, I don't think there's any way to completely turn everything off, but e-diff and some others can be coded out.

I get limiter 4 pretty much all the time on the 335is INA0S stock bin. Might be 100% of the time, I just don't remember, don't run it often and don't log or row many gears when I do. Might be most/all of the time for 3rd-4th shift and not in other gears. Much like I tend to think timing targets are higher in spots than anyone could reasonably realistically use and let DME remove the excess, maybe the stock calculated torque and limits is similar....ask for a lot and let the limiter cap it if needed. There's not really a lot of info out there on the different limiters, but am semi-sure I saw somewhere long ago that 4 was induced by the TCU (whereas some are merely over a limit or cap defined in the DME).

 

[dyezak]

The issue isn’t traction control. Thanks for the suggestion though. The drop in power before upshift and the drop in power after exists all the time no matter the driving style or speed. Something is causing this but I’ve absolutely no idea what. The heat of the engine makes a huge difference with cold starts being its worst and once run, left for a while and then run again it’s almost faultless.

The torque limiters are there. You can see it in your log. TQLM #4 is Traction Control. If it is happening all the time you might have a faulty wheel speed sensor, it could be wildly wrong tire sizes, or severely worn tires.

The logs don't lie, you're having timing go to -7deg every time TQLM #4 hits.

 

[dyezak]

FYI, rule of thumb on a boosted engine is each degree of timing is generally 10hp. When you go from 10deg to -7deg of timing it should feel very evident. That's dropping 17deg of timing or cutting your power by (rule of thumb) about 170hp. You'll feel that for sure.

 

[ManiacGT]

The torque limiters are there. You can see it in your log. TQLM #4 is Traction Control. If it is happening all the time you might have a faulty wheel speed sensor, it could be wildly wrong tire sizes, or severely worn tires.

The logs don't lie, you're having timing go to -7deg every time TQLM #4 hits.

Thanks. Still not sure why it would only happen around upshifts tho...

 

[dyezak]

Thanks. Still not sure why it would only happen around upshifts tho...

Because during a downshift the DME is closing the throttle and the fuel injectors are actually turned off. Any DSC intervention during those activities would be controlled by e-diff engagement or manipulating the brakes.

 

[Torgus]

go back to stock and sell the car?

 

[ManiacGT]

go back to stock and sell the car?

I’d rather not. It is getting on and it’s been a challenging car to own but I’ve grown attached to it.

It can’t be anything big it works just fine other than this hesitation around upshifts. It has to be something simple. It’s just finding it.

 

[RSL]

TQLM #4 is Traction Control.

Do you have some technical source that indicates this? If so, please share, there isn't a lot of info out there on them and maybe more than one can be associated with an event. Limiter 1 is a DSC/TC limiter and anyone can easily verify that. I'm mostly sure 4 is an internal TCU limit, but you seem absolutely positive it's related to TC for some reason.

I’d rather not. It is getting on and it’s been a challenging car to own but I’ve grown attached to it.

It can’t be anything big it works just fine other than this hesitation around upshifts. It has to be something simple. It’s just finding it.

Stock (and probably most OTS) maps are tuned to fall off big over 6000rpm and not sure the rev limiter might not be in play with as high as you shift (unless you're not in manual mode). Try shifting at 6000rpm instead of 7000 and see if the lead up and shift feel different. Post shift is a separate issue, but shifting a little earlier will also put you in different cells post-shift and might alleviate some of the overshoots causing the pulls after. Custom tune would probably fix everything in very short order.

 

[ManiacGT]

I rarely do WOT. For me it’s general driving that’s uncomfortable as just driving in the city and commute exhibits these power drop offs before and after shifts and it makes the car uncomfortable to drive. Lurchy or just weird inconsistent power delivery.

 

[NoQuarter]

go back to stock and sell the car?

Ha.... just hanging around for the part out?

 

[Torgus]

Ha.... just hanging around for the part out?

Shhhh

 

[ManiacGT]

FYI, rule of thumb on a boosted engine is each degree of timing is generally 10hp. When you go from 10deg to -7deg of timing it should feel very evident. That's dropping 17deg of timing or cutting your power by (rule of thumb) about 170hp. You'll feel that for sure.

I definitely feel the loss of power. Comments elsewhere are that this is due to boost mean over target closing throttle though rather than traction and timing. MHD reviewed the log and thought it normal for DCT. It certainly feels like overkill when it happens.

 

[aus335iguy]

It’s far from normal. Call a tuner you’ll not look back and it’s money well spent.

 

[ManiacGT]

The problem started when you went to the dealer ?
What could have changed at that point? Injector coding and they may have updated your DME if it wasn’t already.
Strongly suggest check your injector coding.

So I managed to get INPA working and they are coded, I’d have to take things apart however to check if they match.

 

[Torgus]

So I managed to get INPA working and they are coded, I’d have to take things apart however to check if they match.

The good news is you should only have to check one to see if it matches what is coded in the DME.

 

[aus335iguy]

I would check all 6. Especially Number 4 as timing corrections centre there. ALso when was the last time you changed plugs and coils?
FYI theres an android app called protool by bimmergeeks that can code injectors and other modules, do diagnosis and so on.....

 

[ManiacGT]

I would check all 6. Especially Number 4 as timing corrections centre there. ALso when was the last time you changed plugs and coils?
FYI theres an android app calleprotool by bimmergeeks that can code injectors and other modules, do diagnosis and so on.....

Plugs were done around a thousand miles before the injector related misfire started. Coils are original 9yrs (36k miles)

 

[ManiacGT]

I would check all 6. Especially Number 4 as timing corrections centre there. ALso when was the last time you changed plugs and coils?
FYI theres an android app called protool by bimmergeeks that can code injectors and other modules, do diagnosis and so on.....

Injector coding
DME
1 58.6 2.08
2 58.3 2.16
3 59.4 2.08
4 58.3 2.31
5 58.0 2.06
6 57.8 2.48
Injector (1 front of car, 6 firewall? sequence 1,2,3,4,5,6?)
1 586 208
2 583 217
3 594 208
4 583 233
5 580 206
6 578 248

 

[ManiacGT]

So are the minor deviations on 2 and 4 significant enough to cause issues? Are they miscofigured or due to adaptations?

 

[RSL]

No, you're fine, at least as far as settings. I've had injectors off 0.02 in INPA for years and wasn't a short or long term issue. INPA can set (or show) +/- 0.02 from what was input. It will be dead on, 0.01 or 0.02 off what was input after processing, but I've not ever seen more than that and I've messed around with flow values quite a bit in it. Not sure if there are set bands or a conversion rounding thing specific to INPA. I don't believe all tools have this bump up/down vs. what was input, but INPA definitely does.

You can go back and recode 4 with 2.28-2.30 and see what it sets after processing if you want to play with it, but 2.31 may not be achievable in INPA regardless of what you input (might end up 2.30 or 2.32). There's no need to mess with it that close though, input the values and let INPA do it's thing. The DME is going to manage/trim/adapt when running regardless of what's there, but that may take time and has limits, so you always want a set flow close to reality to make life easy.

For used or remanufactured injectors, no telling what they actually flow now is necessarily close to the values originally printed on them and might have more noticeable issues if they don't.