Ok so I have a new set-up waiting to go on the car but first It has to be running perfect in its current set-up. These are my symptoms:
-Upon start-up the car runs very lean(17-18) afr’s and stumbles very bad on cold start. Sometimes it will choke itself out.
-Once the car is warmed up it idles perfect with afr’s around 15. The real problem lies in driving.
-Once moving the AFR’s are all over the board. Cruizing afr’s are normal but as soon as you get into boost at all the car goes lean (16-17) and sits on its face. -As soon as you back out the car will go rich (down to 10 then unreadable). I know you are probably saying tune but that’s not it because some days the car runs perfect.
-It starts to act like this anytime there is moisture in the air and especially if it has rained. It usually won’t run right for a few days after a rain either. I’ve tried someone else maf on the car and issues persist. Anyone have any ideas? I can provide more information just ask. Anything would be appreciated because we are running out of ideas.

Justin feel free to chime in at anytime.

Mods:
Still on stock ECU
780cc
IX turbo
All bolt ons
272 cams
(car is ready for the RED) 1000cc on standby

Oh yeah the car had this problem a while back but only did this like on one pull once a month. After the 780cc injectors and IX turbo, it became unusual for it to run right. And yes it has been tuned for everything (although not great, not the source of the problem)

Thanks alot guys. Any help would be appreciated
-Jordan

 

Stock ECU? AEM?

Chris

 

stock ECU-edited

 

Well if you are for sure the tune is on you should start looking at vacuum lines with pin holes, tears, ect.. good place to start. Otherwise i would have to see you map.

Chris

 

I have checked for vacuum leaks and it would have to be massive. I have a boost leak tester and will start looking again but that just doesn't explain why on some days it just runs perfect. I can send you my map later today if you think that might shed some light on it. (like i said its not perfect but the fact that the problems are off and on doesn't point me towards tune)

 

How about a leaky injector? Exhaust leak? I would have to say if all that is taken care of then i would have to look at the tune.

Chris

 

leaky injector is very possible. The injectors tick extremely loud. Louder than most other's I have heard with 780's or above. There are no exhaust leaks though of that I am sure. Whats the best way to determine if it is leaking?

 

15 is too lean for idle, my car likes an A/F of about 13.5 to idle best. sounds like your tune. The moist days have a lower barometric pressure, this weather change has an effect on your crappy running engine. Let someone of knowledge take a look at you map and log file and get it right.

 

I bet you get great gas mileage though!

 

2k4EvoVIII
If I send you my map later today can you take a look at it and maybe go over my fuel map a little to try and fix any errors.

 

Since you mention rain and you have an early car I suggest what I wrote to another person on this forum - SEARCH on "electrical problems rain".

 

Ya send me a map and a log please. PM me and i will give you my email.

Thanks
Chris

 

Yea i think that was related to the weather plug behind the driver side fender. If you look under the dash on the left hand side you see a white distrabution block with a bunch of plugs. Pull one out and look for corrosion. But i doubt that is the problem.

Chris

 

fuel pump , lines or the injectors are messin with you.

my car idles fine between 14.3 - 14.6, thats not so lean is it ?

 

We are pulling stuff off a good friends car this weekend to swap stuff out. We will check fuel filters and make sure nothing is clogged and maybe swap pumps just to eliminate it. I am leaning toward my cause is a fuel issue also.