cold start with new engine, wont idle

User topics relating to software that provides a tuning UI to alter ECU code and data

Moderator: Freon

cold start with new engine, wont idle

Postby wittmer25 » Mon Jan 21, 2008 8:01 am

I just finished installing my new engine. I have a gruppe-s built shortblock, diy ported heads, cosworth cams, perrin gt30r kit w/ perrin el header, modded injectors, walbro fuel pump, tvg deletes, perrin big maf, and alot of other crap. I tune w/ enginuity and have a datalog if anyone is interested in looking at it. I programmed all of the idle maps (a,b,c)with 2000 rpm at all temps for cam break-in.

The symptoms are that it seems to be starving for fuel. With engine running, it trys to idle but lower than 2000 rpm. I have correct fuel pressure. I noticed that the front oxygen sensor does not change from 14.7 afr even when the engine is not running w/ the key on. The resistance and current do not change which is strange when the car is running. 0.00 amps & like 255 ohms. There is also zero change in the fuel trims which is also very strange. Is this due to cold start running in open loop?

Before the built block and heads, I had stock heads and block along with the walbro fuel pump, big maf intake, modded injectors, and perrin gt30r kit w/ header. It ran fine with my personal tune.

I did not change any timing maps or fuel maps (i didn't think it was needed to get the motor started and cams broken in), only the idle map values. I don't have any check engine lights either. I was thinking maybe a intake manifold vacuum leak, but my boost gauge shows plenty of vacuum and I still think it has something to do with the oxygen sensor.

Any insight would be much appreciated.

Jonathon

EDIT: Oh yeah, the car/ecu is an 04 STi
wittmer25
 
Posts: 2
Joined: Tue Apr 24, 2007 3:29 pm
Location: Waco, TX

Postby Freon » Fri Jan 25, 2008 5:47 pm

That is odd with your oxygen sensor. You have a wideband, right? What does it say?

Did you change your fuel injector scaling?
Freon
 
Posts: 700
Joined: Thu Nov 17, 2005 5:50 pm
Location: Indianapolis, IN

Postby wittmer25 » Sat Jan 26, 2008 12:56 am

sorry, i tried to relocate my maf sensor during the reinstall. I relocated it back to the original position and it fixed the problem.... besides the obvious vacuum leak i had.... lol. so by the way i have been driving it for a week now. its been running well.

jonathon
wittmer25
 
Posts: 2
Joined: Tue Apr 24, 2007 3:29 pm
Location: Waco, TX


Return to Tuning Software

Who is online

Users browsing this forum: No registered users and 7 guests