Timing pull only on one cyllinder

[Dj_Quik]

Originally Posted by NCM2C

any update? i'm in a similar boat with constant cylinder 4 misfires. Mechanic used a scope and saw some "shine" on piston 4. I am holding my breathe until tomorrow when they do compression/leakdown.

i havent scheduled my leakdown test yet, ,but please update me on your test results!

[Dj_Quik]

Originally Posted by sly1types

The middle cylinders are the first to pull timing b/c of the extra air flow on the manifold design.

my buddy who tunes his own car on bm3 said i shouldnt worry too much about it. he says his car pulls timing on cylinder 5 consistently like mine does on cylinder 4. he says as long as timing recovers from initial timing pull, it should be fine and im just tripping too much.

[Dj_Quik]

Originally Posted by sly1types

One thing that is crazy is you are running 28lbs of boost. Stock is around 20. I would guess the car is tuned.

wait what? i didnt know stock was 20 lbs. lately bm3 has change the psi reading to psiG or psiA. im trying to figure out which one is the right one so i wasnt paying much attention to the boost targets but i was thinking the other day that 28 psi is unusual. and no, afaik this car isnt tuned. i checked with bmw before buying this car and it has never been flagged for a tune either.

[TopJimmy]

Originally Posted by Dj_Quik

wait what? i didnt know stock was 20 lbs. lately bm3 has change the psi reading to psiG or psiA. im trying to figure out which one is the right one so i wasnt paying much attention to the boost targets but i was thinking the other day that 28 psi is unusual. and no, afaik this car isnt tuned. i checked with bmw before buying this car and it has never been flagged for a tune either.

You want PSIg because it’s “gauge” pressure. The PSIa is “atmospheric” which adds 16PSI at sea level.

When you watch boost look at the pre-throttle and MAP values to see what PSI you’re at. They should be very close since the first is read before the throttle body, and the second is read at the intake manifold. Boost target doesn’t mean much.

[Dj_Quik]

Originally Posted by TopJimmy

You want PSIg because it’s “gauge” pressure. The PSIa is “atmospheric” which adds 16PSI at sea level.

When you watch boost look at the pre-throttle and MAP values to see what PSI you’re at. They should be very close since the first is read before the throttle body, and the second is read at the intake manifold. Boost target doesn’t mean much.

got it. i looked back at my old logs from a few month ago and compared em with my latest ones. MAP psi and pre throttle psi have always matched up. but just a few months ago my psi would be 13-15 psi with wgdc tapering to 80 mid pull. the latest logs are reading 28 psi but with pretty much same wgdc. i dunno whats going on. wgdc should be almost pegged at greater than 90 if im pushing 28 psi no? no indications of boost leak either. maybe bm3 is not reading psi accurately since the updates.

[TopJimmy]

I must admit I’m m confused by your logs, because I do see 28PSIg on both Boost and Target, which would be normal for a hot tune but not for stock. Perhaps BM3 isn’t reading the sensors right. I would go into my Stock Tune and make sure every single setting was set to OEM, and then re-flash.

Also, having WGDC of 80 is pretty good, but at 28PSIg on stock turbos is like WHAAAT???

[Dj_Quik]

Originally Posted by TopJimmy

I must admit I’m m confused by your logs, because I do see 28PSIg on both Boost and Target, which would be normal for a hot tune but not for stock. Perhaps BM3 isn’t reading the sensors right. I would go into my Stock Tune and make sure every single setting was set to OEM, and then re-flash.

Also, having WGDC of 80 is pretty good, but at 28PSIg on stock turbos is like WHAAAT???

This is a problem. Because i havent even unlocked the ecu yet. Ive just been using bm3 to log engine parameter ls and try and correct engine stuff before i do go tune it. Was really just going to try and flash the m4cs bmw tune first. Anyways, this is so weird and im going nuts lol

[papasmurf_m3]

Consistent timing pull in the same cyl is not normal. You might have some issue there. Did you get a compression and leakdown test?

[Dj_Quik]

Originally Posted by papasmurf_m3

Consistent timing pull in the same cyl is not normal. You might have some issue there. Did you get a compression and leakdown test?

not yet. i need to go do a log again. been running injector cleaner to rule the injector out first. havent been pushing the car hard anyways. is there a way to test injectors on ISTA? i seen a video but it was for diesel injectors.

[Octavio.f82]

Did you end up doing a test, or any update? Just did a log and my car shows it’s pulling time on cyl 4. I’m going to do another log and check with tc off. And then I’ll check plugs. I got new injectors, coils, and plugs were done not to long ago.

[SWFL_M3]

I’m following this. I’m also getting corrections just on cylinder 4 after changing plugs and coils.

[hellokitty]

Are you guys logging only after being in Sport+ for 5 minutes before logging?

My tuner always asks for logs in Sport+ after driving in that mode for several minutes before the log.

The reason is now that temperatures are getting hotter, it seems like timing corrections are normal due to less air density because of higher ambient temps.

Less air density = turbos working harder and hotter to hit target.

[Dasky_spas]

Originally Posted by Dj_Quik

i havent scheduled my leakdown test yet, ,but please update me on your test results!

You had your leakdown 'scheduled' months ago. Any update here? No reply in months..

[Dj_Quik]

Originally Posted by Dasky_spas

You had your leakdown 'scheduled' months ago. Any update here? No reply in months..

Nah i didnt go through with it. Its an intermittent issue and my tuner has been adamant that ive been getting phantom knock. The car pulls hard. Doesnt throw codes or misfires so ive stopped worrying bout it. Ive had couple other issues that needed to be fixed anyways like my intercooler leaking so the compression and leak down tests have yet to be done. The car is runnjng well so thats less incentive for me lol ill get them done eventually.