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Can’t fix a misfire at idle

1K views 6 replies 5 participants last post by  Weste46  
#1 ·
I’m having trouble solving a misfire on my Car, anyone on here want to help me diagnose it? I’ll explain everything.
Car is a 2003 bmw 325ci (M54B25) and I***65039; am throwing a p1353 (misfire cylinder 6 with fuel cut off) and also when I***65039; get low on gas with around 50 miles to empty I***65039; throw a p0313 ( misfire with low fuel detected) and occasionally p0171 and p0174 lean codes, these may or may not directly be related. So far I’ve replaced the maf, the ccv, spark plugs, valve cover gasket, cleaned the idle control valve, replaced cylinder 6 injector, replaced the fuel pump but the one I***65039; received in the mail was worse than the one in my car so I sent it back, when I***65039; move coils around the misfire remains at cylinder 6, I’ve replaced intake boots, smoked the car and found no vacuum leaks besides a small one at the sucking jet pump( hose that brake booster attachment to firewall is on) I***65039; have fuel trims available I’m just not sure how else to approach this. Basically I***65039; haven’t replaced the o2 sensors and the fuel filter, and the fuel pump I***65039; suppose since I***65039; sent back the defective one. Any help is greatly appreciated!


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#2 ·
So does that mean then that the fuel pump hasn't been changed?
 
#5 ·
Need Fuel Trim and Freeze Frame data to start with. Lean codes are a problem, these need to be understood and identified.

While you claim you have smoke tested once, are you aware of the 3 vacuum ports under the rear of the intake that usually have 1 or 2 caps that split and/or fall off.

Not that I am indicating this is fuel pump related at this point, I want to be clear on what you have done with the fuel pump. You have not changed/replaced the original fuel pump, you removed the original and the replacement was faulty so you reinstalled the original fuel pump, correct?