aip

I got my V-AFC hooked up and started to tune it. I went out and would start at about 2000 rpm in 3rd, floor it and then tune the A/F throughout the rpms to be between 11:1 and 12:1. When I floor it in 1st and 2nd, it runs to rich, but 3rd and 4th seem to be ok most of the time. Some times it just runs between 8:1 and 10:1 all the time. I checked the plugs and they look good. A little too black around the base, but the electrode was a nice dark gray/brown. The bad thing is that it sucks at accelerating. You floor it and it just sits there and takes forever to go anywhere. It climbs, but really slowly. I had it in 2nd at 3000, floored it, the A/F was 12:1, boost and fuel pressure all ok, and it barely accelerated!?! It gets up to about 6500 and takes off pretty good, but anything below that and its crap. Also, idle EGT's are 900 F, cruising they are about 1300-1400 F, and sometimes at about 70% throttle in 4th or 5th, it can hit close to 1600 F. I took the MSD BTM off thinking it might be messed up and retarding the timming, which if retarding too much, it can increase the EGT's a lot. I hooked up the MSD 6AL and it was the same. I changed the battery and that didn't help either. I don't know what else it could be other than something with the ignition. What else would make it not accelerate and run high EGT's? Any ideas on what it could be would be great. Thanks.

Adi Radoncic

Ok ammm answer these questions for me...

1. What Turbo are you runing trim and a/r's please.
2. What is your throttle position set to on the vafc?
3. What are your egt's when your sitting at full throttle?

I can tell you right now that you are running rich when you are cruzing so bring your egt's down to 1250 degrees.
Also you might be running just a little bit lean when idle so bring your egts down to about 750-800 degrees...

Adi

aip

Look in my sig. for what i've got. My throttle settings are 25% - 75% i think. At WOT, my correction % goes from -30% at 1000 rpm and slightly increases to -1% at 8000 rpm and 0 at 9000 rpm. WOT EGT's range and increase by each gear and get up to 1400 F - 1450 F normally, but sometimes when it sputters around 4000-5000 rpms it can come close to 1600 F. I have a greddy wide band O2 + A/F gauge and it goes to 8:1 to 9:1 A/F at lower rpm's. Any ideas?

dustin

The greddy gauge isn't wideband though...

boostaholic

8:1 A/F is extremely rich down low, you may be dumping in too much fuel. My car won't even stay idling with the A/F ratio at 9:1. Your WOT EGT's are ok, could be a tad lower. Try taking out some fuel down low and adding a little in the upper RPM range.

VaporTrail

aren't PEM systems wonderful?

aip

hahaha, it ended up being the cam gears. they slipped and the intake cam was retarted all the way. runs great now. thanks anyways. what kind of times should i be running?

VaporTrail

ooh, that could definately suck heh heh, been there once or twice.