Anyone see what's causing the hesitation? / General Comments

[DramaFoYoMama]

I've been having what I thought was a really bad misfire. I changed the plugs, but that wasn't it. I'm beginning to think it's a fuel delivery problem. Does anyone see anything in this log I took tonight? I didn't scan very many PID's , but there are experts on here that I swear can read an LS1's mind. Also, are there any general comments on the scan that anyone sees? I know it runs hot. I'm going to eventually get around to swapping out the thermostat.

BTW, the "misfire" is only below 2k RPM's. As long as I get above that and give it steady throttle, there's no problem. I'm going to swap the fuel filter when it stops raining.

[Delco]

What size cam do you have ?

[DramaFoYoMama]

It's stock. BTW, I've been on this tune for over 2 years with no incident.

6.0 stage III heads, Fast 90/90, 422, FIPK II, speed density open loop

[Delco]

You need to log a wideband and see what is going on , commanded afr looks pretty lean and your o2's never move ?

[DramaFoYoMama]

I don't use my O2's. Also, I keep it lean under cruise, but you can see that it goes to 14.68 (sometimes a little lower) under acceleration.

[5.7ute]

Just cause you are commanding a certain AFR doesnt mean you are getting it. Best to follow Delco's advice & do a log with a wideband.
I am pretty sure that trying to log misfires without a working maf is pointless as they dont work without it.

[DramaFoYoMama]

I originally tuned it with an LC-1, but I'll get it hooked up again when I get some time. Thanks for noting that the misfire reporting doesn't work without a MAF. I never knew that.

[joecar]

In you previous logs, what was your idle MAP kPa...?

[joecar]

You might be too lean for throttle tip-in... as 5.7ute said a wideband is needed to verify this.

[DramaFoYoMama]

I'm not sure what my idle MAP pressure was before. I'd have to dig out my old laptop hard drive. As for the tip-in, it was never a problem until about a month ago. I'm going to have to break out the wideband, but I'm not going to be able to do that until May. I have a ton of work I have to get done in the next month.