Still having acceleration hesitation/startup issues

Likeanowl · 10-19-2020, 08:05 AM

About a month ago I had my car in because it seemed to be hesitating while under light acceleration and 1 in every 5ish startups it would crank an extra few seconds. It had catless dp’s but is now back to stock. While in for the swap I let them know the issues so they kept it for a few days to see what they could find. After the downpipe swap was complete they scanned for codes and got nothing at all. Not even a single misfire could be found and claimed everything was working fine. For a few days it was, but now instead of cranking longer it appears to almost “shutter” at startup every so often now. And between speeds of 30-40mph if I keep my foot just barely on the gas for light acceleration the whole car lightly jerks sort of like the common DCT jerk were all used to but not as hard.

Anybody have any clues? Is this just all in my head? I feel like if it was a real problem surely some sort of code would be thrown, no? I’m still out of work so just paying for all sorts of tests isn’t exactly what I want to do but I guess if I have no real ideas I’ll have to. I swore it had to be the plugs/coils or even injectors but they said not a single misfire code was found. This is extremely frustrating.

TopJimmy · 10-19-2020, 12:56 PM

Stock intakes or aftermarket?
MAF sensors clean?

Likeanowl · 10-19-2020, 02:02 PM

Stock intakes now. I cleaned MAF’s with MAF cleaner. Also showing no MAF codes.

Robbie135 · 10-19-2020, 02:12 PM

I had something similar happen in my 135i before I got my M. I didn't have any misfires or anything but once I swapped my coils it went away. Not saying it will work for you but it's something to try out

Likeanowl · 10-19-2020, 02:17 PM

Quote:

Originally Posted by Robbie135

I had something similar happen in my 135i before I got my M. I didn't have any misfires or anything but once I swapped my coils it went away. Not saying it will work for you but it's something to try out

See and I thought of that. My worry is I’m gonna then have to play the whole “that didn’t work what’s next?” game and wind up spending thousands with possibly no fix still. Is it possible to test my coil packs without having to remove them and all the labor associated with it?

TopJimmy · 10-19-2020, 02:54 PM

Yeah, we were trying easiest and cheapest first. I thought coils or plugs too. Yeah that's next to look at. Try using BM3 to do a log of a solid 4th gear pull from 2K-7.3K RPM (30-135mph). Then scroll through the log and compare the cylinder timing of 1 through 6. Seeing an anomaly here might indicate which cylinders to focus your plug/coil check.

I'm going to E85 soon and will DIY a plug and coil swap from OEM to real Flex-Fuel plugs and BavAuto coils. The job looks fairly easy, but I've done all my bolt-ons myself except the hub (Kies).

If you were to do a refresh of OEM plugs and coils yourself the parts/tools (through ECS) will be cheaper than just the labor of having a shop troubleshoot. One shop quoted me $700 for labor alone to do a plug swap...HaaaaaaNooo

10-19-2020, 08:05 AM	#1
Likeanowl Captain 1153 Rep 711 Posts Drives: BMW F80 M3/ Yas Marina Blue Join Date: Aug 2019 Location: Ohio iTrader: (0)	Still having acceleration hesitation/startup issues About a month ago I had my car in because it seemed to be hesitating while under light acceleration and 1 in every 5ish startups it would crank an extra few seconds. It had catless dp’s but is now back to stock. While in for the swap I let them know the issues so they kept it for a few days to see what they could find. After the downpipe swap was complete they scanned for codes and got nothing at all. Not even a single misfire could be found and claimed everything was working fine. For a few days it was, but now instead of cranking longer it appears to almost “shutter” at startup every so often now. And between speeds of 30-40mph if I keep my foot just barely on the gas for light acceleration the whole car lightly jerks sort of like the common DCT jerk were all used to but not as hard. Anybody have any clues? Is this just all in my head? I feel like if it was a real problem surely some sort of code would be thrown, no? I’m still out of work so just paying for all sorts of tests isn’t exactly what I want to do but I guess if I have no real ideas I’ll have to. I swore it had to be the plugs/coils or even injectors but they said not a single misfire code was found. This is extremely frustrating.
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10-19-2020, 12:56 PM	#2
TopJimmy Major General 5450 Rep 5,143 Posts Drives: 2023 M3 Comp xDrive Join Date: Jul 2019 Location: Chester County, PA iTrader: (5)	Stock intakes or aftermarket? MAF sensors clean? __________________ '18 F80 Base 6MT \| '19 F82 Exec DCT \| '18 F82 Comp Exec DCT \| '23 G80cx
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10-19-2020, 02:02 PM	#3
Likeanowl Captain 1153 Rep 711 Posts Drives: BMW F80 M3/ Yas Marina Blue Join Date: Aug 2019 Location: Ohio iTrader: (0)	Stock intakes now. I cleaned MAF’s with MAF cleaner. Also showing no MAF codes.
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10-19-2020, 02:12 PM	#4
Robbie135 Private 3 Rep 52 Posts Drives: 2016 F80 M3 SSII Join Date: Jan 2016 Location: San Diego, CA iTrader: (0)	I had something similar happen in my 135i before I got my M. I didn't have any misfires or anything but once I swapped my coils it went away. Not saying it will work for you but it's something to try out
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10-19-2020, 02:54 PM	#6
TopJimmy Major General 5450 Rep 5,143 Posts Drives: 2023 M3 Comp xDrive Join Date: Jul 2019 Location: Chester County, PA iTrader: (5)	Yeah, we were trying easiest and cheapest first. I thought coils or plugs too. Yeah that's next to look at. Try using BM3 to do a log of a solid 4th gear pull from 2K-7.3K RPM (30-135mph). Then scroll through the log and compare the cylinder timing of 1 through 6. Seeing an anomaly here might indicate which cylinders to focus your plug/coil check. I'm going to E85 soon and will DIY a plug and coil swap from OEM to real Flex-Fuel plugs and BavAuto coils. The job looks fairly easy, but I've done all my bolt-ons myself except the hub (Kies). If you were to do a refresh of OEM plugs and coils yourself the parts/tools (through ECS) will be cheaper than just the labor of having a shop troubleshoot. One shop quoted me $700 for labor alone to do a plug swap...HaaaaaaNooo __________________ '18 F80 Base 6MT \| '19 F82 Exec DCT \| '18 F82 Comp Exec DCT \| '23 G80cx
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