LS1 #7 Cylinder

[mistermike]

I wonder if there is a possibility of being able to change the injector balance to address the #7 cylinder leaning out. Grand Prix GTP owners are able to tune out a #3-4 lean condition with another tuner package. Would this be a matter of building this capability into FlashScan, or would it be an inherent limitation of the PCM? This would be a great boon to fellows running forced induction, and probably allow a little less "paranoid" fuel tuning.

[GMPX]

Sorry for the delay........I don't think the LS1 PCM can do individual cylinder fuel triming. I might try to look further into it.

Cheers,
Ross

[jfpilla]

Sorry for the delay........I don't think the LS1 PCM can do individual cylinder fuel triming. I might try to look further into it.

Cheers,
Ross

I don't think so. There are two 02 sensors, so it would seem only each bank can be controlled.

[GMPX]

With the power of the CPU's in the current PCM's it would be possible to detect things like the mixtures of each cylinder with only 2 O2's, individual cylinder fuel trims, individual cylinder spark control, individual cylinder knock detection. Just that GM felt the LS1 didn't need any of that fancy stuff!!

Cheers,
Ross

[mistermike]

Thanks for the response. The #7 problem has been a pain from the git go. If there's no software solution, I'm kind of surprised no one has come up with a hardware approach. I seems like a post-ecm "pulse stretcher" to increase IDC by a fixed percentage on one injector lead could be concocted without too much trouble. I imagine it would be a little crude, since it wouldn't "know" any other parameters, but it might have a similar effect of having a slightly larger injector on that cylinder.

[kompressor]

DEPAC has an interface module out that has the ability to monitor and log WB in as many cylinders as you wish by placing individual sensors in each respective header tube location, thus enabling the user to closely watch developing AFR during a run where the engine experiences different load delta's with varying RPM.

We used to use that in Pro Stock Truck in NHRA, but I don't know if something like that could be adapted to the EFILive stuff though...

[Highlander]

LT1s do have a cylinder balance calibration.....

maybe its there?

[kompressor]

Very good idea.. If one is going to use the cyl. balance feature, it would be a wise move to have some way to closely monitor that, or each cylinder's AFR for calibration accuracy and engine protection. The DEPAC could do that, but I'm not sure it's worth the expense...at least for a street car IMO.