Worse mileage driving "nicely"

[papasmurf]

I have been driving my a3 jetta for over a year now. Fittest thing i did was change all filters and diesel purge. I wasn't getting over 33 mpg. I drove it that way for 6 months and after it couldn't get out of its own way i ordered pp764's knowing i would be upgrading things in the future.

The power alone from the nozzles was amazing. Right before the nozzles i adjusted the timing just under the top timing line. Same thing. Mileage was the same driving spirited everywhere. Last month i changed my iq from 1.8 i believe to about 5.0.

Now my last tank i got about 30 mpg driving very nice, not going over 2500 rpms. I actually lost mileage. I have also cleaned the intake manifold and intake ports as best as i could when i first got the car.

Anyone have any suggestions? A chip tune maybe? I mean it runs great and compression is admit 500 psi across the board. I did block off my breather on the block with an 8v block off plate.

Thanks everyone. Just want that 40 plus mpg these things are known for.

 

[fruitcakesa]

Check your brakes.
The 02 was getting 34+- mpg average for the past year and I attributed that to the auto trans, malfunctioning turbo actuator and lots of short, local drives.
Turns out both rear brakes were dragging slightly, one due to corrosion on the slides that caused the pads to hang up and the other to a failing caliper.
I have not filled up since the repairs but judging by how slowly the fuel gauge has been dropping, I know FE has increased.

 

[papasmurf]

They all spin freely. I had also changed the rears to disc brakes.

 

[Jesus Is Lord]

Check for codes. Then adjust you IQ to about 6.5-7.0. And do it with a hammer mod not with VCDS.

 

[papasmurf]

When i put the iq at 5.0 that was with the hammer mod.
The only codes i am getting are intermittent ground faults for the airbags and 01237 which is the fuel cutoff solenoid intermittent ground fault

 

[Jesus Is Lord]

Make sure Maf is in spec. Check vacuum lines, wastegate actuator, IQ, Boost, Timing, Ect. Check everything you can think of while driving the car. I really don't know what else to tell you. You can also adjust the IQ to 7.0. And clean the grounds.

 

[UFO]

What temperature is your coolant? Are you getting full boost?

Temperature and air are instrumental in getting full efficiency.

 

[papasmurf]

Yes maf is in spec at least at idle. Need to do some logs except the clutch can't hold much. Vacuum lines were tripartite and i have checked and cleaned grounds under the battery tray. I have also wrapped up the wires that get chafed up under the tray.
I will say that i had the vacuum line going to the egr valve off the nipple and plugged up. I have since hooked it back up and the power is still there. I will try putting the iq at 7.0

 

[Jesus Is Lord]

What temperature is your coolant? Are you getting full boost?

Temperature and air are instrumental in getting full efficiency.

It could easily be the thermostat.

 

[papasmurf]

Well the gauge says i believe 205 to 210 consistently but maybe vag Com will say different

 

[papasmurf]

Consistent 200 degrees f. Was a little cooler tonight though

 

[Jesus Is Lord]

Does the Injection pump leak?

 

[turbocharged798]

Completely normal. These engines are most efficient under load. Driving it harder will result in better MPG.

Shift no earlier than 3K when accelerating.

 

[papasmurf]

No i replaced the pump head seal when i first got it. I think i know what it is. I only live about 7 miles from work in horrible stop and go traffic. Warm up time is almost non existent. These short distances is what i think is causing the horrible mileage

 

[UhOh]

No i replaced the pump head seal when i first got it. I think i know what it is. I only live about 7 miles from work in horrible stop and go traffic. Warm up time is almost non existent. These short distances is what i think is causing the horrible mileage

Yup. Pretty widely known that these cars aren't for short/quick city trip driving.