Ugh, another 3.0 Misfire thread....

[19jdog]

First off I never post new threads cause there so much info on the B6. Google is my friend. But this time I'm stumped. Ever since I pulled the motor out for my 6 speed swap ive been getting misfires. All my connections are good and ive changed a bunch of crap out;



Used ECU with JHM 3.0 tune
New spark plugs NGK gapped to .44
New Coil packs latest ver
New pre cat sensors
New pcv valve
New vacuum hoses
New Vacuum Actuator Valve $400.00 cough cough

I have a 63 mile commute every morning to the bay area. I leave at 5am. On the way in my car runs great. No misfires. On the way home between 1.30 and 2.30pm I get misfires. Same speed in to work and home 75 to 83 mph. Car at 3100 rpm. average (damn S4 6 gear too hi IMO)

BTW EACH TIME I GET THE FLASHING CEL THE CAR IS RUNNING FLAWLESS. NO LOSS OF POWER, NO SURGE, NOTHING

Address 01: Engine Labels: 06C-909-559-ASN.lbl
Control Module Part Number: 8E0 909 559 D HW: 8E0 909 059
Component and/or Version: JHM* V3/9X G 0003
Software Coding: 0016711
Work Shop Code: WSC 63351 000 00000
VCID: 366D2B6D42107E8E81-515A
5 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 -
16687 - Cylinder 3
P0303 - 001 - Misfire Detected
16686 - Cylinder 2
P0302 - 001 - Misfire Detected
16688 - Cylinder 4
P0304 - 001 - Misfire Detected
16689 - Cylinder 5
P0305 - 001 - Misfire Detected

Readiness: 0000 0000



Some times cylinder 1 misfires but never 6. To day 1 and 6 are good

Any ideas?? This is driving me crazy!!!!!

[road_tripper]

I was getting intermittent multiple misfires on my 3.0.

After I did the timing belt service myself, no more misfires.

not sure if belt was stretched, the first timing belt service done at the dealer was done incorrectly, or some other problem.

But I've had zero misfires in over 20k miles since I did the timing belt. In the 110K miles between 1st and 2nd timing belt services, I had at least 16 multiple misfire events (with flashing CEL light). Probably had more more but that's all the vcds logs I saved.

But if you're getting misfires at the same place on your commute, why not fire up vcds and log a bunch of sensors and see if your maf is going nuts or IAT sensor hiccuping or some other wierdness.

or... maybe you should just avoid vacaville?

[imnuts]

How many miles on the car? Any chance you could log the AFR and MAF readings going to/from work? I would guess that it is either a bad air flow reading, or a fueling issue. It sounds similar to mine, though my misfires started a cylinders 3 & 5, then moved to 6, 4, 2, 1, pretty much in that order every time. Changed out the fuel pump and have yet to have any misfires since doing so.

[19jdog]

How many miles on the car? Any chance you could log the AFR and MAF readings going to/from work? I would guess that it is either a bad air flow reading, or a fueling issue. It sounds similar to mine, though my misfires started a cylinders 3 & 5, then moved to 6, 4, 2, 1, pretty much in that order every time. Changed out the fuel pump and have yet to have any misfires since doing so.

176,000 miles. Damn didn't even think about the fuel pump. I have owned the car for 2 and a half years. I have changed the fuel filter within the last 6 months. I couldn't imagine that the original fuel pump is still in the car (2004), but who knows.. I'm going to change the filter out today.

What does AFR stand for?

[19jdog]

AFR

air flow reading

[SJorge3442]

AFR

air flow reading

Air/Fuel Ratio.

I agree with imnuts. I think this is a fuel pump issue. He was having issues with random misfires like he said and has been great ever since he swapped it out. I bet you're still on the stock pump. The pump is on my list of things to replace before I have issues with it.

[imnuts]

I was over 190k miles on the stock pump, and didn't start making any noise until maybe a month before a changed it. Even then, the noise was barely audible, and not consistent. New pump and all had been well since.

Sent from my Nexus 6

[19jdog]

Ok FINE, new pump it is. I'm gonna have so many new parts on my car. Sh!t Oh well. I just drove my daughter to a after school function. Fuel pump was silent.

I bought a new fuel filter at the dealership today, my vin says a fuel regulator is in the filter. Guess it could be that too.

[19jdog]

ok new fuel pump and fuel filter installed. I still have the same problems. It is still happening at 3200 or above rpm. If I stay below 3100 it never happens. Like I said before I get a flashing CEL with no loss of power...



Tuesday,22,December,2015,18:28:18:22275
VCDS Version: Release 15.7.2 (x64) Running on Windows 10 x64
www.Ross-Tech.com

Address 01: Engine Labels: 06C-909-559-ASN.lbl
Control Module Part Number: 8E0 909 559 D HW: 8E0 909 059
Component and/or Version: JHM* V3/9X G 0003
Software Coding: 0016711
Work Shop Code: WSC 63351 000 00000
VCID: 366D2B6D42107E8E81-5178
6 Faults Found:

17947 - Clutch Pedal Switch (F36)
P1539 - 004 - Implausible Signal
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 - - Intermittent - MIL ON
16688 - Cylinder 4
P0304 - 001 - Misfire Detected - Intermittent
16687 - Cylinder 3
P0303 - 001 - Misfire Detected - Intermittent - MIL ON
16686 - Cylinder 2
P0302 - 001 - Misfire Detected - Intermittent - MIL ON
16689 - Cylinder 5
P0305 - 001 - Misfire Detected - Intermittent

Readiness: 0000 0000

[imnuts]

Any chance you can log it and get the misfire counts for the cylinders, as well as the MAF reading and

[junxing]

OP, when you changed your PCV did you replace the PCV hoses as well? Have you done anything with the injectors? Spike had a thread on it: http://www.audizine.com/forum/showth...o-restore-flow