my setup:

b18b turbo (td04hl),
forged block (pistons&rods) 8.89:1 CR
uberdata, crome
450cc dsm blue top

we put my car on the dynapack yesterday and for my idle to be perfect as stock we had to lean to 22:1 other than that it was too sluggish. Is it possible?? I mean I don't think a car can even idle at 22:1, we plugged in a PLX WB (other sensor as well) and at idle it was at: LEAN hence the WB was not faulty, the bong is placed just after the flex pipe (I know a flex sucks) the flex is a bit rusty, is it a leak?? How can I chek if it's aleak or not?? where could the leak be manifold? turbo flange? any ideas?

one other problem is when I hit full boost the car hesitates it's like the injectors are not correctly opening. In vacuum even at 60mph on the highway the car runs flalessly, spark plugs are new btw. Could a bad resistor box or bad grounding can cause this other problem? what would likely be the cause? we have tried several fuel maps (uberdata and crome) it always does the same. I know it is alot of questions, but if you were me where would you check first??

thanks alot!!

 

I'd first put your wideband in a stock vehicle and see if it idles at/near 14.7:1. If yes, then your car is not getting enough fuel one way or another. If no, then your wideband is screwed up.

Honestly, why in hell are you hitting boost if you don't even have idle adjusted correctly yet?

 

My stock h22 boosted with precision 680 injectors idles at "LEAN" also. I too have a plx wideband. My car was dynotuned and has been running on this tune since last august.

 

17 or 18:1 i believe is fine at idle but 22 sounds high. but then again are u really gonna cause damage idling? Just call local tuner.

 

you can hear when a car idles fine,, we put the af at 14.7 but it was sluggish,it idles like stock (sound wise) like I said at 22:1,, I hited boost to see if it was ok didn't hold 5th gear for 20 minutes though, anyway I bought a resistor box and change it next week to see if it is parrt of the problem, my speedo needle is going crazy as well, maybe a ground issue?? I'll double, triple check every connections.

thanks, and feel free if you have any other inputs.

 

we tried with 2 WB so I don't think it is the WB the problem. A leak would be more probable,, but I have to find it.

 

I'm running 8.5:1 compression on a b18b. I had to raise the timing to get a good idle. I raised mine up from 16.5 to 17.5

 

Try another dizzy as well. My speedo and tach went crazy right before mine went out.

 

wow i didnt know a plx could read that far out....mine reads out to 19.9 at most....only time u should see that number is when u let off the gas imediately...

 

The plx reads 20:1 at the most above that it indicates LEAN,, so that's why I'm saying that my idle was "LEAN" The wideband on the Dyno can read farther than 20:1. Anyway it really shouldn't be idling as good as stock at over 20:1 AF,, I was looking for some opinions here....

 

you have an exhaust leak or its a bad sensor.

 

SOCH_MShue -> you are saying that it is impossible for a car to idle at 22:1 (that was my thought)

how can I verify if I have an exhaust leak? How can I narrow my search??

thanks.

 

yea sounds like a leak to me.

 

if the car is really at 22:1 a/f at idle, it wouldnt idle all that well. it will idle but the car might shut off if u open up the throttle and let off at around the idle rpms

 

A misfire or unburned fuel reads as a LEAN condition. For some reason it sounds like not all the fuel is getting burnt. When it reads 14.7 to 1 it is telling you that is the ratio of BURNED fuel to oxygen. It might be chugging out half a liter of unburned gas, the WB won't tell you that, and that's why it idles like poo at that AF.

Or as stated it could be a leak into the manifold/exhaust pre-sensor

Try pulling the plug wires one at a time, does the idle not change with any of them?

 

My PLX read LEAN at idle on really hot days. Car always ran fine while driving.

 

Yeah mine too. Reads lean at idle, but idles fine and no leaks.

 

Different voltage at idle throwing the PLX off maybe? Anyone have a dedicated 14V supply they can run the PLX off of separate from the car?