Fighting-First

Purchased my A4 about 3 years ago and this cold start problem has been a killer since.

Stone cold start, OK, drive the car out of the garage maybe 1/4 mile and it starts breaking up almost like its to rich. When the symptom starts and the car gets gunny, I punch it the car stumbles for a second then pulls fine, let off the gas (cold) and it will stumble again.

Let the car idle to N.O.T. and the problem doesnt appear, only when a load is applied and the engine is cold or cool.

This problem has been getting worse over time, now the car will stall if I try punching the gas when gunny. Start the car after a stall and the problem is gone. The car will also give me the symptoms on warm starts only if the car has been sitting over 45min or its cool.

I try to make sure my car is in good working order and have replaced many items trying to solve this problem among others.

Any additional ideas to compliment the work list below is appreciated.

The VAG doesnt come up with much only saying "Low Fuel Random Misfire"

New ICM
Rebuilt MAF (OEM Filter)
New N75
New silcone vacuum tubing
New BPV
New check valves
New suction pump
New Coolant Temp Sensor (dark green)
Checked the Vacuum Purge OK (top of airbox)
New Fuel Pump Relay
New Plugs
New Fuel Injectors
New FPR
New Primary OEM 02 Sensor
New Secondary OEM 02 Sensor
New Fuel Filter

The only other things I can think of is the Air Intake Temp, Crank or Cam Sensor.

Any ideas?

Thanks

ModifiedA4

what does block 32 say?

Fighting-First

I always mix up 031 and 032, not sure if 032 is Voltage or Fuel trim but nothing erratic happens with the B1 02 voltage.
My problem is fuel trims have changed recently because I installed a Perfect Power SMT7 that is controlling the trim and boost. However this problem roots from bone stock days.

The only code that pops its head is the B1S1 02 Sensor "No Activity intermittent" but rarely. I would like to know why there is no activity?

Thanks for the help, I know several others have this problem and knowone has solved it.

Yippers®

Check injectors and FPR

Fighting-First

Yup new 310cc Injectors and 3bar FPR both came with my GIAC-16

Fighting-First

approx 6 months from the stealer. That hurt my pocket the most....

Yippers®

Might also check the Barometric Pressure (BARO) sensor. Tha tinfluences cold start enrichment too

Fighting-First

Thanks, will check them. Why the Baro Switch?

Yippers®

pressure limits and mixture at engine start-up. If it is fragged it will be more of a problem at cold startup than at warm restart.