Multiple misfires temporarily on cold start

vonxolo · 10-28-2024, 02:02 PM

2009 528i E60

My car has been doing this rough idle, misfires, for a couple minutes in cold starts.
During this issue the gas pedal is nearly unresponsive. After a couple minutes it just starts to run normal.
I’ve recently replaced the fuel pump, and am pretty sure I need to replaced the filter and sending unit.
Could this be related to the filter? It seems more electrical by its behavior, like the fuel module possibly?
And help appreciated

Schomosport · 11-12-2024, 02:21 PM

After a host of troubles, where cold start roughness was the least of my troubles, I replaced the HPFP with a new one. Since replacement I get a little rough running on a cold start, less than half a minute, where the engine runs rough and if you try to drive off straight away it bogs down and won't pull the skin off a rice pudding. I find giving a quick rev immediately after starting helps. After the first half minute it is no trouble the rest of the day. I have aduff nox sensor, too tight to change it since I don't really understand what casued it to fail and they are expensive. I suspect it might be injectors but alreadyb spent so much money that so long as the fuel consumption remains OK and it passes UK MOT I live with it. (2007 330i). Had similar with a 335i, that tended to misbehave a mile down the road but soon cleared. BLack art these things.......

10-28-2024, 02:02 PM	#1
vonxolo Registered 0 Rep 3 Posts Drives: E60 528i xdrive Join Date: Feb 2023 Location: Nebraska iTrader: (0)	Multiple misfires temporarily on cold start 2009 528i E60 My car has been doing this rough idle, misfires, for a couple minutes in cold starts. During this issue the gas pedal is nearly unresponsive. After a couple minutes it just starts to run normal. I’ve recently replaced the fuel pump, and am pretty sure I need to replaced the filter and sending unit. Could this be related to the filter? It seems more electrical by its behavior, like the fuel module possibly? And help appreciated
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11-12-2024, 02:21 PM	#2
Schomosport New Member 5 Rep 25 Posts Drives: 525i Join Date: Jul 2023 Location: ENGLAND iTrader: (0)	After a host of troubles, where cold start roughness was the least of my troubles, I replaced the HPFP with a new one. Since replacement I get a little rough running on a cold start, less than half a minute, where the engine runs rough and if you try to drive off straight away it bogs down and won't pull the skin off a rice pudding. I find giving a quick rev immediately after starting helps. After the first half minute it is no trouble the rest of the day. I have aduff nox sensor, too tight to change it since I don't really understand what casued it to fail and they are expensive. I suspect it might be injectors but alreadyb spent so much money that so long as the fuel consumption remains OK and it passes UK MOT I live with it. (2007 330i). Had similar with a 335i, that tended to misbehave a mile down the road but soon cleared. BLack art these things.......
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