First off I'm running a saab setup on 6psi an 04 cavalier. I'm running lsj injectors, cartech 2025 fmu with the hahn fuel rail fitting and the stock fuel pump. Atmospheric fuel pressure with the vac line disconnected is like 40psi, once its connected it goes down to about 15 20psi at idle. Under boost afr drops to low 12's to mid 11's then to the mid 10's and high 10's and stays there. So under boost afr is fine to me. Question is under light acceleration it'll start of in the 13's and will stay in the 14's afr. Is this normal? Is it normal for it to be in the 14's afr under light acceleration? I want to turn up the atmospheric psi up to the 50's which I read was the correct psi but I have the top screw in all the way in and it only goes up to 40psi, any thoughts on this? Any advice?
Normal driving AFR's seem pretty good. Normal driving you should be in closed loop so the ECU should be shooting for 14:7:1.
FU Tuning
Put it on the dyno and I think you'll find that mid 10's are too rich for best power and overkill for "safety factor"
Have any changes been made via HPT?
it's the eco reflash, can't tweak t he re flash
I don't have the eco reflash just an fmu and lsj injectors, and only change with hpt is pe delay was changed since its an 04, don't have the money for hpt and my friend which does is around 4 hours away lol as soon as I get a chance I will be driving up and have him tweak it a bit
another question for you guys, if i drive the car for a while and turn it off for a couple minutes and turn it back on itll idle pretty rough, and my wideband goes up to like 20:1afr then after ideling for a minute or two it will idle fine and go to 14.7;1 at idle, any thoughts on this?
cavipower1 wrote:another question for you guys, if i drive the car for a while and turn it off for a couple minutes and turn it back on itll idle pretty rough, and my wideband goes up to like 20:1afr then after ideling for a minute or two it will idle fine and go to 14.7;1 at idle, any thoughts on this?
Yes it's idling bad on cold starts while in open loop. Once it warms up and goes into closed loop the computer is managing to correct fuel to make it idle better. Work on adjusting your base fuel pressure (on cold starts), you might need to increase it to richen it up while engine is cold.
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Hahn Stage II - Mitsu TD06-20g |3" Turbo-back Exhaust | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | Team Green LSD | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
Yea but this happens once its up to operating temp. If I wake up and turn it on it idels fine but if I drive it for a while and the engine is still hot and right after that I turn it off andet it sit for a minute and turn it back on it will idle like crap only wen I turn it off after a bit of driving and turn it back on, cold starts it idles fine though
I know my o2 in the downpipe is brand new cuz I bought a new one, the secondary one in the exhaust was completly blk and had like black stuff caked on there, against my friends reccomendation not to I cleaned it with brake cleaner. Could that messed up sensor be causing this?
I didn't say it was worn or bad. I said it wasn't heating up in time.
Do realize the primary 02 sensor is not heated.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
ok so also the fact that it may be bad wouldnt cause this?
You problem with the sputter and lean part. Could be a few things. One you could have a exhuast leak when warm( seen it a few times) not getting the o2 hot enough. Or it could be that the o2 isn't coming up to temp quick enough becuase of higher flowing exhuast or something around that.
So basically what sweetness said he knows his stuff so i would listen to him.
What brand of o2(the first one did you go with? Tell me not bosh or the cheapest you could find). Change the first one to a heated o2 will help with higher flowing exhaust. I would buy a universal ac delco or the ac delco o2 for the rear and put it in the front and wire it up to a 12volt source and gorund it.
Now the rear o2 doesn't do anything but moniter the cat. Did you get a check engine light after you cleaned it? Or have one for it before for the rear? If not it is still good more than likey. What you could do is take the cat o2 and put it in the front and wire it up. Then take the one from the front and stick in the rear but don't wire it up(zip tie the wire somewhere). And drive it and see what it does. You will get a check engine light but it won't hurt anything. And if your buddy has hp tuners he can disable the rear o2 so the light goes off.
They both have a point on the O2 sensor. To find out if the O2 sensor is the problem do the following. Disconnect the primary O2 sensor from the wiring harness. Leave it in the exhaust, just unplug it. Drive it for a day, maybe even just half a day. Come back and tell us if it still does it.
FU Tuning
okay ill try that, sounds easy enough haha
