Road Trip--Problems

[dumbo]

heres the story, it was running good, i drove it down to bc,1500kms. runns good the whole way, get home and its idleing 18:1 i was like wtf, shut it off went to bed. in the morning same thing, reset my ecu, same thing.

i got a maft pro SD, so i reset that and set it up again, with 02 connected and try disconnecting and doing PTT. only way i can get a decent idle afr is cranking the mainscale up to like 40%, then the thing cant drive worth a shit.

What could of happened to make such a dramtic change?? Somone please some help i've tried everything, and i'm going back out to try everything else. thanks

 

[DangoAZ]

Dumbo -

I had the same thing happen after a long road trip. I'm running MAFT-Pro...

I'm not entirely sure what caused it, but I think it was too much heat. My O2 sensor got "nuked" with the AZ summer heat, and it was accordingly no longer in calibration. I recalibrated my sensor, and low and behold I was back in the AFR envelope I was always running. I know that my O2 sensor manual recommends a much shorter interval for recalibration on turbo than n/a, and I'm guessing it's due to heat (experts can chime in here).

It could also be a boost leak, or rather a vacuum leak when you're out of boost - If there is air being sucked through a hose upstream of the AFM, it won't have a metered portion of gas assigned to it and you'll be lean. Depending on what mode you are running your MAFT... speed density will compensate. AFM translation will not. Anyway - A boost leak test can't hurt.
Edit: Just re-read the post and saw SD = Speed density. Nevermind - that shouldn't be your problem.

It could be a poor fuel injector, or low fuel pressure too, but try the easy stuff above first.

 

[GrimJack]

I ran into the same thing with the MAFT Pro once. I just unplugged it, waited 5 seconds, then plugged it back in, and the problem went away.

 

[dumbo]

well i tried all.. nothing, so i unplugged my stock o2 and went Part throttle afr tracking, shes running alot better, but i gott add like 60% fuel at low load 400rpm, and like 20% at 800rpm and 5% at 1200rpm, mainscale is 0, and sometimes it just acts different, like WOT runs good 11.5afr then sometimes it drops to 9:1afr, and same thing with light throttle, run like 14:1 then drop to like 10:1, cant understand this thing. has a mind of its own. does this thing 'learn' over time because i change one thing and its great, the next day its different.