The stock injecters would never beable to keep up with that setup

 

If hes just driving conservatively (non PE mode) then the trims should still be able to accommodate it. From what i've seen on cammed cars, the pcm actually needs to remove fuel at low rpm/low throttle points due to reversion.

If he's getting on it (in PE mode) then yeah if anything the car should run really lean, but he is saying the car is rich. Thats what doesnt make sense to me. A tune is a good idea, but i think one or more of his sensors is screwed up too.

 

More than likely he is getting knock retard due to the big cam and the longtubes on his stock tune. I didnt notice a LT4 knock module listed in his mods. That could very well be causing him to run rich during normal cruise mph and while stopped at lights etc. His car would only run lean at WOT and he would more than likely notice it due to fuel cut, however 80% of the time the car would be running rich trying to overcorrect due to all the noise from the cam/headers....

I could be totally off key here, but it sounds logical.

 

If there are injectors in there and the computer doesn't know it will never be able to compensate for that.

Bret

 

thx a lot for all replies,mi car is runing like a crap,tomorrow i will change new plugs,do you now what is the exact Gap for the plugs for N/A ?,also mi car is overheating a little more than usual but i think is because of the termostat 160 and the fans are programed to start late,well i think with stock radiator ,and stock pump and more ´´power´´ without tune is normal to happend that,as they mentioned i will also put the lt4 knock module to prevent the knock retard.

 

.035" will work for a gap.

 

make sure you are using the right plugs as well i'll look at my motor tomorrow and tell you what lloyd said to use. mine were wring in the beginning

 

i bought NKG TR5´s i think that should work good.

 

NGK VR7 is what Lloyd says to use with the LE2 setup

 

I have used MadZ28 for my tune, and I have to say, maybe its just me, but I get crappy customer service. I e-mailed him over a week ago asking about a possible problem with my tune, and have heard nothing...

 

I have a LE2 383 set up.....those plugs were too cold.
Much happier with TR6 or 103's.

 

Tow it to the tuner or you will be making more threads later trying to figure out why your car isn't running right.

Otherwise get a mail order tune from Ion.

 

You are totally correct, in theory. The computer should be able to compensate (BLM's) for the change in air flow, granted he didn't put bigger injectors in it. The problem comes when the car goes into closed loop and starts using the O2's. The cam has enough overlap to allow unburned fuel/air to enter the exhaust system. This unburned fuel/air is seen as a 'lean' condition. Remember, the O2 sensors detect how much oxygen is in the mix, not fuel, and in this case, it's seeing the increase in oxygen. The 'lean' condition will cause the PCM to try and compensate by making it richer and richer. Before long, the car is running extremely rich and the plugs are gas fouled. You can tune these things in closed loop, but it would take much longer than just tuning in open loop.

Also, for the OP, an LT4 KM will only filter out the noise of the valvetrain. Loud exhaust, clunking, etc. will cause KR and it won't necessarily go away with a LT4 KM.

 

I know Ion said he can de sensitize the stock KM and you wouldnt have to get a LT4 KM. I was on the DYNO last weekend with the Stock KM and there was ZERO knock retard.

 

Let me make sure I understand you:
You are saying that in closed loop, the cam overlap causes a false lean condition which will cause the trims to drift richer and richer over time?

But then how could you ever get a closed loop tune that worked? No matter how you set the airflow tables up, unburnt a/f will always get in to the exhaust and always cause a false lean and cause the computer to add more fuel than desired.