DemonicPupil

Alrite, I've finally got the Turbo project up to speed. The car starts and holds an idle, however it is running lean. Assuming the O2 sensor is working (I bought a new one to install tomorrow JIC). It was covered with oil from a bad turbo, so I don't know how that would affect its performance. It should have all been burned off by now...

Anyways, my real question, after hours of reading... I need to get this back on the road as a daily driver.

Would my Variable Resistor for the Idle mixture need to be adjusted for the TurboII mani's??

Here's what I have so far...

S4 TII mani's ported to 6 port
NA throttle body
All emissions removed
AFM (level)->Intercooler
No turbo, just header till replacement turbo gets here
No vac leaks as far as I can tell (new gaskets and hoses)
Vac pressure is at 20 psi at around 1k rpm idle
Have done plenty of messing around with the fast-idle screw and TPS, with no improvements

Car runs at +30 on AFC to be "stoich" on a narrowband. Car "used" to run about 1-2 bars rich on my narrowband, but now can't get back to rich. Lots of popping and etc. Runs rough and wants to die.

I was able to get the AFC at 0 and have the same AFR with the fast idle screw turned almost the entire way down and the TPS at a small amount out (haven't used a digital tester).

New turbo is on the way, but for the time being, need to have the car running. Will put turbo back on when I purchase a set of bigger secondaries. (2 of the 550's i purchased were no good)

Thanks in advance for help....

Aaron Cake

iTrader: (1)

The car should read lean at idle if the emissions sytem is working properly. You will also not get an accurate reading from a narrow band non-heated O2 sensor at idle because it will be too cool. Also the O2 sensor does not effect the idle.

DemonicPupil

On a stock ECU? At idle, they should run rich. When they run lean, they suck ***.

I've left the car run plenty long enough to heat the O2 sensor. Also took it out for a drive.

I know the O2 sensor doesn't affect idle, however if the O2 sensor were to be giving me a bad reading, then I've been trying to get this car into the rich on idle, and lord knows, it's fruitless if it's already rich and i don't know it.

The car is lean/stoich throughout the power band... so i know something is wrong..

Anyways, seems I have leaks at the injectors or somewhere close to them. When I spray starting fluid near the secondaries, the car starts to die. I figure I'm sealing it up, and cutting off the air. So back to the drawing board. Damn injectors have brand new grommets, caps, etc.

Aaron Cake

iTrader: (1)

On a stock ECU with all the emissions controls, the car should read LEAN at idle.

Don't try to tune idle with a narrow band O2 sensor. It's just going to cause a headache.

That'll do it.

HAILERS

Is it a turbo ECU and a turbo pressure sensor? Or a combination of the two? You don't want a combination of the two i.e. n/a and turbo parts concerning the above two parts.

Are they stock 460 or stock 550 injectors? or?????

Never mind if the injector leakagei is the problem.

DemonicPupil

Guess the threads i read that said the idle should be in the 13's were wrong. Also, before pulling all of this stuff, the car idled rich all the time. When I tried to turn it down (to save some gas) it would start to die at about -6 as the idle went stoich. This was before making the swap.


The injectors are the stock 460's for the time being.

Can I put some RTV or gasket sealer around the injectors? These have brand new everything on them, why the hell aren't they sealing?

Aaron Cake

iTrader: (1)

On a narrowband, the idle will read full lean (generally off-scale) on a stock car with emissions controls. The airpump is pushing a lot of air into the exhaust manifold to help combust left over fuel and keep emissions down. When the emissions controls are removed, the sensor will read a little into the rich zone. Remember that a narrowband is only accurate for a few percent around stoich.

Don't use RTV. It will just make a mess. They should seal if they have all new rubber but if there was crud in the hole when it was inserted then there could be air leaks.