Jeff_Jeske

iTrader: (66)

Lately when logging my car I have been seeing my AFRs go lean (12.3) up top. First thing I did was add fuel to the high octane map and when doing that I saw the stock injectors climb over 100 duty cycle but no change in AFRs.

I then replaced the stockers with 1050's and my AFR still went lean. My WOT fuel map is set at nearly 8.3 across the board and still I'm not getting the fuel I need.

The car has a walbro and I had heard those things like to take a dump sometimes so I pulled it out and swapped it with my 5k mile stock EVO9 fuel pump. Same condition. WTF

Now I'm starting to think my zietronix wideband might be the problem. It reads afr at idle just fine and I see normal behavior at cruise and such .... the only possible misinformation is at WOT. Does anyone know if this is indicative of a dying senor? Mine has seen hundreds of gallons of leaded fuel but until recently I noticed no change in its output.

Could there be something else that is limiting fuel delivery? I'm hunting for another wideband to test with but probably won't find that anytime soon.

tscompusa2

iTrader: (22)

its also important the injectors are scaled properly or the fuel map wont do jack.

is the walbro 255 modded? is the relief valve punched in? if not do it! it will fix your issue.

A bad wideband will read full lean just during cruising and etc.. highly doubt its the wideband.

Jeff_Jeske

iTrader: (66)

After posting I did some searching and came across this thread:
https://www.evolutionm.net/forums/ae...02-sensor.html

My issue is a duplicate of the commentary here:
https://www.evolutionm.net/forums/6924109-post4.html

I'm fairly certain that healthy unmodded walbro 255 should be able to supply enough fuel to keep AFR's below 12.X. I'm not certain but it seems like a fair assumption as it wasn't till recently that people started modding the pumps.

The other thing that has me thinking it might be the WB is the fact that I wasn't seeing any knock and a quick look at the exhaust tip has it covered with more soot than ever before. I know these aren't very scientific but they are what they are.

I plan to pick up a new bosch sensor tomorrow from the VW dealer or parts store. I'll keep you in the loop but I'm still looking for additional feedback.

Jeff_Jeske

iTrader: (66)

Well good news!!! Napa had a replacement Bosch sensor and I replaced it this morning. Made a few pulls and the AFRs were in the 10s. It appears it was indeed the sensor that was on its way out.

Thanks for the input.

nightwalker

Thanks for the update. Good to know for future reference. My wideband is getting pretty coked up too.

tscompusa2

iTrader: (22)

nice and easy fix. for future reference to check the sensor before buying a new one without knowing if its the sensor or not check this out:

http://www.youtube.com/watch?v=1mb4VmDd0ao

sparky

iTrader: (1)

Is the 110 "jungle juice" that you run leaded? If so, do you think that the lead is probably what did the sensor in? Will you be switching back to your Walbro pump or keep the IX pump in the tank?

Jeff_Jeske

iTrader: (66)

Yea its leaded. I'm actually surprised it lasted as long as it did. At least my front O2 is still going strong. Since it only takes 15 minutes, I swapped the Walbro back in this morning.