I need tuning help BAD

[robertisaar]

the O2 should "swing" from ~200 to ~800mV on a regular basis when it's warm. sounds like your narrowband is messed up.

[90v65speed]

I changed the o2 sensor and it works right now. I also got a3400 tune to start with that runs pretty good hopefully with a little more tweaking it should be running good. Do you think there is any more power to be made by running a different tune for premium fuel. Maybe run more timing. I have the switchable chip adapter

[robertisaar]

you'll only see benefits on premium if you're running enough compression to the point of running into knock before hitting peak power on regular.

[Superdave]

there is more power to be had from that bin, the main spark advance is the stock 3.1 table. from 90 to 100kpa, 2000 RPM up to 4000 RPM change all those to around 26 degrees, 4000 to 4800 change to 28 degrees.

in your datalogs watch for knock counts above 4K, you should be fine on a fairly stock engine though. Also watch your WOT fueling, you may have to bump the VE adder table up a little above 4800.

[90v65speed]

I drive it some last night and I still have a problem.it is still wanting to cut out st 3500 in second gear. Its intermittent though so I don't think its the tune. its like it shuts off almost, falls flat on its face and pops out the exhaust. I'm thinking ignition but don't know what? I changed the injectors to multitech twos because I thought that was the problem. It was better for a little bit now it is doing it again.

[Superdave]

check all your engine grounds, seen that before.

[90v65speed]

I was having a problem with my alternator not charging very high. I put a 10 guage wire from the battery to the alternator and is better now. I also put a 4 guage for the battery to the ICM mounts. It still does it. I will try another body ground and see if that helps.
Brent

[Superdave]

the ICM doesn't ground through the mounts, only the ground wire from the 2 pin power plug.