Just need a gut check to see if I've covered all the bases in my tune

[robert5656]

I have been tinkering with HP tuners off and on for a while but am far from a pro. I'd like to get some more experienced tuners to look at what I've done with my bone stock LS1 Corvette.

Here's the tune (Corvette-2.hpt) and a log file from this morning (6-13-19.hpl). You can see pulls to ~6,000 RPM in 1st and 2nd gear at about 4 minutes into the log. I forgot to turn TC off and got some serious wheel spin so TC cut the throttle to 40% there but at least it didn't knock 4 degrees like it did in the "6-11-19" log using the "Corvette-1" tune. I set PE to come on aggressively in the "Corvette-2" tune and dialed the EQ back to 1.176 from 1.134 to richen it up and keep knock at bay. ECT and IAT were within 1 degree of each other on the two logs so that eliminates variables.

I'm getting ready to go on a road trip with the car so I'd like to get some other eyes on what I've done to make sure I haven't done anything stupid with my tune and if I've left anything on the table.

Thanks

Rob

[5FDP]

Seems odd that everytime you floor it the o2 sensors take a noise dive. Normally they should swing rich up around 880-930mv to show that fueling is there. It's not a super accurate way to judge but can at least show something.

I'd be curious if fuel pressure falls like a rock when you go wide open throttle. A dyno would make seeing that easy, otherwise I've taped a fuel pressure gauge to the windshield before and just fished the line out the hood to reach.

Otherwise with it being a stock engine, not much can go wrong. Timing isn't super aggressive and the rest looks fine.

[robert5656]

You're right. I didn't see that. Sometimes they go up to almost 900mV like they should and sometimes they go down to around 30mV. They also went dead a few seconds after I came off WOT and both of them read 3mV. What would cause that?

Car has 91,000 on it and I assume they are the original sensors. Just replace them or do I have another problem?

[robert5656]

I've been reading the forums and it's been said that a MAF that is on it's way out can cause this. I have had the P0101 code pop up now and then - like once a year.

Does the MAF frequency that I've logged here look right?

[robert5656]

Here's a log file from my drive home from work. Still having random events where the O2's just go to zero during WOT and cruise.

When I got home, I cleaned the MAF sensor wires with a Q-tip soaked in electrical parts cleaner and got just a little bit of dirt off of them. I'll log another drive tomorrow morning. Hopefully just cleaning the MAF does it.

[robert5656]

Ok, I went out and logged two more drives after cleaning the MAF sensor and the both show the O2s going up to almost 900mV as expected every time I went into PE mode. Trouble is, they still randomly drop off to near zero while cruising. Is that normal?

[5FDP]

If you get off the throttle and coast, which I did see in that log. It is normal to have them drop away, you can also watch your injector pulse width drop to nearly zero. The engine is entering DFCO (decel fuel cut off).

It's the dropping to zero under power or at WOT which would be a cause of concern.

[robert5656]

Dang, you're right. Everytime the O2s go to zero its going into open loop because DFCO has engaged. Well, Sir you have helped me learn something today. Thanks!