I've been trying to troubleshoot a problem with my Vortech setup and appreciate any suggestions. The car dyno'd 340whp/218wtq at 8.5psi a week ago and at that time it was running fine. A couple days later, it started to idle really bad and afr's started fluctuating between 14.5 and 15.5 at idle. If I let it idle, afr's continue to rise as high as 17's and eventually it shuts off. The car starts up immediately right after but the idle/afr problem persists. It only starts happening after about 10 minutes of driving, otherwise it's fine before that. It's been professionally tuned on AEM EMS Series 2.

So far I've checked for vac leaks, replaced spark plugs, map whack and cleaned iacv to no avail. Any suggestions as to what changes after the car fully heats up that may be contributing to this? When I pulled my plugs, two were normal but two showed half rich, half lean. Does this indicate a fuel pump or injector problem?

My setup is:
Vortech V-3 @ 8.5psi
AEM EMS Series 2
AEM Serial gauge, UEGO wideband
ID1000cc injectors
Aeromotive fuel pump, rewired
SOS tb, SOS 3 bar MAP

 

In their instructions, SOS recommends the injectors get cleaned and flow tested. Are you using the stock wiring and connectors? If not, it's possible there's inconsistent signal between cylinders?


It does seem the cylinders are inconsistent, which could be causing the O2 sensor to vary its readings when it reports, and your ECU is trying to compensate.

 

I am using the factory harness along with the plug and play connectors. On the dyno and for the first couple days, the car ran fine at ldle, partial throttle and WOT. Today, it runs fine until after about 10 mins of driving. Once this starts, even partial throttle results in higher than usual afr's.