Cold Start Delete BM3 Cat Heating Delete

Icy340 · 11-20-2020, 02:34 PM

Anyone using the BM3 cold start delete on their tune ? I've had it in for the last 2 months
after installing my downpipes. I've noticed a really rough cold start & idle, anyone else deal with this as well? Car shakes heavily on cold starts 50% of the time.

Mods are are BM3 STG 2 91, CTS catted downpipe & dual resonator delete

leew102 · 11-20-2020, 07:22 PM

I had cold start delete turned on on stage 1 with stock cats, mainly because I let the car warm up a bit before I drive off. I noticed that I had some really rough cold starts where the car would start then drop down to around 800 or 900 rpm then would drop down to the normal 600ish rpm but what would happen was the car would keep dropping below the normal 600 and would cause for rough idles so I turned the cold start back on.

Icy340 · 11-21-2020, 02:36 AM

Quote:

Originally Posted by leew102

I had cold start delete turned on on stage 1 with stock cats, mainly because I let the car warm up a bit before I drive off. I noticed that I had some really rough cold starts where the car would start then drop down to around 800 or 900 rpm then would drop down to the normal 600ish rpm but what would happen was the car would keep dropping below the normal 600 and would cause for rough idles so I turned the cold start back on.

Appreciate the reply ! Yea I noticed the idle is getting rougher. I always let the car warm up before I drive as well,I'm just gna take it off. Not worth harming the car, neighbors gotta deal with it lol

G.Newt · 11-21-2020, 03:20 AM

You're in Cali, so probably don't experience as cold as temps as we do in Denver. With cold start on, with my car sitting outside, my car would literally stall (6-speed) if I tried to go before it was done with the cold start procedure. With it off, it does do the rpm fluctuation at first, but then is good to drive after a minute or so warmup. Now that it's garaged, even with an E30 tune, it starts right up with no issues. Idles pretty steadily at 800-850rpm initially, then drops to 600ish after a minute or two.

Supr3me · 11-21-2020, 10:34 AM

Quote:

Originally Posted by Icy340

Anyone using the BM3 cold start delete on their tune ? I've had it in for the last 2 months
after installing my downpipes. I've noticed a really rough cold start & idle, anyone else deal with this as well? Car shakes heavily on cold starts 50% of the time.

Mods are are BM3 STG 2 91, CTS catted downpipe & dual resonator delete

I'm assuming you guys are all on OTS maps. I experienced the same with OTS and with some of my early custom tune revs. I mentioned it to my tuner and he added fuel on startup and the problem went away completely. I feel like MHD and BM3 need to add a table that looks at "if cold start delete = true; add fuel on start"
I'm no tuner but doesn't seem like that'd be hard.

Icy340 · 11-23-2020, 01:27 PM

See I thought it was just me, yea that would be a good option. & your correct I am running OTS map, after taking c start off no issues since then

kern417 · 11-24-2020, 07:53 AM

I've had mine off for a year and a half, running ots maps and custom tune, and it's never been a problem.

11-20-2020, 02:34 PM	#1
Icy340 Private 42 Rep 60 Posts Drives: BMW 340i Join Date: Sep 2020 Location: California iTrader: (0)	Cold Start Delete BM3 Cat Heating Delete Anyone using the BM3 cold start delete on their tune ? I've had it in for the last 2 months after installing my downpipes. I've noticed a really rough cold start & idle, anyone else deal with this as well? Car shakes heavily on cold starts 50% of the time. Mods are are BM3 STG 2 91, CTS catted downpipe & dual resonator delete
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11-20-2020, 07:22 PM	#2
leew102 Private First Class 83 Rep 163 Posts Drives: F30 BMW 340i xdrive Join Date: Jul 2020 Location: NY iTrader: (0)	I had cold start delete turned on on stage 1 with stock cats, mainly because I let the car warm up a bit before I drive off. I noticed that I had some really rough cold starts where the car would start then drop down to around 800 or 900 rpm then would drop down to the normal 600ish rpm but what would happen was the car would keep dropping below the normal 600 and would cause for rough idles so I turned the cold start back on.
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11-21-2020, 03:20 AM	#4
G.Newt Major 811 Rep 1,452 Posts Drives: CT4-V Blackwing 6MT Join Date: Feb 2017 Location: CO -> TX iTrader: (0)	You're in Cali, so probably don't experience as cold as temps as we do in Denver. With cold start on, with my car sitting outside, my car would literally stall (6-speed) if I tried to go before it was done with the cold start procedure. With it off, it does do the rpm fluctuation at first, but then is good to drive after a minute or so warmup. Now that it's garaged, even with an E30 tune, it starts right up with no issues. Idles pretty steadily at 800-850rpm initially, then drops to 600ish after a minute or two. __________________ 2022 CT4-V Blackwing 6-speed SOLD: 2016 340i xDrive 6-speed DAW v2.5 turbo E40 \| Dorch S2 \| VRSF DP \| MST intake \| AWE catback \| 335is clutch \| CSF heat exchanger \| RK Autowerks intake manifold \| Orange M Perf Brake Kit \| KW Street Comfort coilovers \| GTS taillights V2
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11-23-2020, 01:27 PM	#6
Icy340 Private 42 Rep 60 Posts Drives: BMW 340i Join Date: Sep 2020 Location: California iTrader: (0)	See I thought it was just me, yea that would be a good option. & your correct I am running OTS map, after taking c start off no issues since then
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