athenG

iTrader: (2)

I have a weird problem with my A/F and Utec. A few weeks ago I slept over at my Mother-N-law's house so I had to park my car on the street and on top of that it rained that night. I left the place the following day and I noticed that my car was running extra rich. I had to subtract 2%-3% on the Temp Compensation to get my A/F back to normal. Now fast forward 2-3 weeks, I had to go to a graduation party last night and it was raining. I noticed that my A/F was Lean. Lean as high 12's to low 13's when on boost (dont worry I wasnt boosting hard only 2-4psi just so I can see how my A/F changed) I went home and disconnected the battery overnight. Now I went out for a drive and it was still Lean as hell. I had to add 4% on my Temp Compensation to get me back to safety.


Now my question is how do you know if one of the injector went bad? I don't know if it is the injector coz adding 4%-5% kinda help fix my A/F but I also had to subtract 2%-3% of fuel a few weeks ago from my original tune. I also have two wideband (Innovate on bank 1 and the Tuner on bank 2) and both are displaying Lean #'s. So if one injector failed then one bank should be lean and not the other..(unless both side had a failing inj.). I don't have a Fuel Pressure gauge so I don't know if my Fuel Pump working properly.

The only thing changed for both occasion was that it rained but I never had any problem driving in the rain.

athenG

iTrader: (2)

Dont really know why the suddent change on my A/F but everything seem to be ok. Idle, cruising, WOT all seem to be normal except me adding more fuel. My car even feel much stronger!!! I drop my full boost to 6.5-6.8psi and I feel that the car pull much stronger than my 8.0 - 8.3psi boost map

I don't really know what could cause this sudden change It is not like all of a sudden the temp changed much lower and the air density got higher, it is pretty much in the same temp area (11C-20C and 21C-30C). If temp changed then it usually get higher especially during the day so air density goes down hence I should get Richer A/F Any Idea guys?

UpRev

iTrader: (5)

You should grab a cheap Marshall oil filled Fuel Pressure gauge just for peace of mind. I'd start with testing all sensors and making sure you don't have any exhausts leaks ahead of the O2 sensors. If that all shows up right, then it's time to have the injectors cleaned and flowed.

zerosec

iTrader: (3)

^ Monitoring Injectors Duty Cycle won't help ?

athenG

iTrader: (2)

I don't think so coz you can have the right duty cycle but if the fuel pressure is down then that will hurt you too.

Update:
I forgot to mention that the week that my car wen Rich was also the same week that my Meth controller went crazy. When I drove the car, my car was going to limp mode. Then I tried to fill up my Meth tank, it was almost empty. I think the controller sprayed all of them and it went to my Intercooler. I think that cause me to have a Rich A/F coz the air was blowing the meth in my FMIC back to my TB. I think after a week or so the Meth all dried up and now hence my A/F went back to normal and because I had to subtract some fuel before and that could be the reason my A/F shoot up to the Lean side. Again this is just thoery..lol I have a new controller now and I'll see if things changed again. I really need a Fuel Pressure gauge!!!