Newbie with his first data log

[mowton]

Hey Russ,

Bet you are glad I am back OK, we are back from PA and I have logged a few runs/idles. With tune #5, the car runs pretty good. Gas mileage was great as well

The idle hunts ever so slightly normally, but on ocassion (happened while I was backing up into a parking space upon ariving at the resort) the idle will drop and almost stall the car. I have to feather the pedal a bit to bring her back. On one ocassion after a 3rd gear pull to reline, I decelerated and pulled over to save the log and the idle dropped very low, surged hi, back to low for several cycles until I could feather the pedal to calm it down. Additional note, very strong smell of sulfur at this time. Last observation on the trip...when I was stuck in traffic and I turned on the AC, the car wanted to die. It was warm (70 plus) out and it was stop and go traffic.

Of note in the MAF scan is 3950 (gradual runup from 3200hz to 7900hz), 4050 (commanded 16 AFR), 6750 (6% TPS to 100% stab), 6900 (3110 to 8300hz pull) and 11000 (3rd gear pull from 4900hz to 9500hz)

Thanks for all your help

Ed

[Russ K]

Ed

I don't understand why the commanded AFR goes up to 16 at times. As far as the sulfur smell, I removed 4* idle spark and added 1 g/sec RAF. I also set up your open loop table.

With a large camshaft, sometimes you will have to hold the throttle open until the idle stabilizes. My car has a 229/242/.630/.630/114 camshaft, and for the most part it starts & idles great. But the odd time, I have to hold the gas pedal for the idle to catch.

Russ Kemp

[mowton]

OK, it has been a long while since I posted on the tuning progress. Idle is very good including when AC is on and even in hot weather and heavy traffic. Quite pleased

MAF tuning is in good shape and trims hover around the 0 to -5 values. again quite pleased

I've bought a wideband and it is being installed in the car as we speak, so I really haven't done any PE/WOT efforts yet. Am really looking forward to that

Now, with all this extra time on my hands (remember...time is the devils worshop), I have been messing around with VE scanning. I know Russ, you said leave it alone but I was curious)

If I did it correct, set MAF fail frequency to 0, stayed out of PE (as best I could ) and logged about 40 miles worth, I was surprised to see the average trim offsets to be in the -14% range. Doesn't that say that I would have to actual decrease the stock VE table? I thought with the addition of the Vararam, cam, heads and headers, the ability to ingest air would actually go up, meaning I would have to increase the values in the table

I've included the tune and logs for review. The only "funnies" I have right now is after a hotsoak start, the car feels sluggish in low RPM take off's and sometimes drops it's idle to 400 or so and then does a 3 phase hunt and seek to arrive back at the 1050 idle setting and what led me to log the VE, was a slight hesitation when I take off while the car is in warmup (80F to 178F).

Sorry this is so long but wanted to add as much info as possible. Once the Wideband is installed, we will tweak the WOT on the DYNO/street and then it's off to the track to see the rewards of your efforts

Thanks again Russ

Ed

[mowton]

ttt

[Russ K]

Ed,

Like I said before, just leave the VE table alone. But if you what to reduce the fuel trims, you lower the VE by the % the trims are off by.
Tuning the VE by fuel trims is not a good plan, a wideband should be used instead.

Looks like you need to remove ~1 g/sec from the RAF table.

Russ Kemp