1BadZ95

I'm tryin to get some tuning done on my LT1 car and I'm having a problem of getting my a/f right under a load. In 1st and 2nd when there isn't much load on the engine at wot the a/f is 11.9 down low and as the RPM's climb at about 5k the a/f gets to about 12.8 which is where I want it. When I hit 3rd the a/f will go down to 11.3's or so and climb up to 12.3 or so and in 4th the a/f goes to 10.0, and climbs to maybe 11.0. We need to work on the high freq maf tables. I need something to datalog and correlate afr vs rpm vs maf freq. What can I use to do this? I'm using a LM-1 handheld wideband.

Thanks!

C_Rules

iTrader: (7)

thats and better throttle response is why i run speed density . put your car in SD mode and log it to see if it follows a similar pattern. may not be a maf related issue.

1BadZ95

Does unplugging the maf put the car in sd mode?

C_Rules

iTrader: (7)

for some. mine wouldn't back in the day. i just enable it through the switch tables in tunercats. try unplugging it. if that don't work maybe lt1edit has an option to enable sd mode.

1BadZ95

Oppps! I dont know why the hell I put lt1 edit in the title. I'm using tuner cats.

C_Rules

iTrader: (7)

then go to the ecm switch tables and enable sd mode. then you'll knowf its the maf that's messing up your a/f or something else.

Michigan Skip

What does your duty cycle look like during that time.

1BadZ95

Duty cycle never gets above about 79%. I'll try the sd switch.

Michigan Skip

Have you tried to just bump the numbers at those lower rpm levels way down in the PE tables. I had to use ridiculous numbers to get mine to where I wanted them. Although my problem was just the opposite of your situation

1BadZ95

I put them at -8.00 from 0.00 and it didn't really change much. -8.00 Means its requesting a 13.7 a/f. I didn't want to go much more than that.

C_Rules

iTrader: (7)

put it in sd mode and check it out. if it does the same thing i would check your spark plugs. mine would do something similiar when cylinders 1 and 7 were dead due to ignition and fueling issues.

1BadZ95

I know I don't have dead cylinders. I was talking to my buddy who is helping me with this (he tunes a lot of ls vehicles with hp tuners though), and I was asking him what it would take to tune my car in sd and just get rid of the maf all together. He said we still have to have some way to tune the VE. We need something to output whats happening in the narrowbands.
How does VE Master work? Anyone use it?

C_Rules

iTrader: (7)

i use ve master its pretty straight forward. you insert your log and tune and it spits out a new tune. car has to be in sd mode for it to work properly.

what do your BLMs look like now?

1BadZ95

So wait. Why does the car need to be in SD mode for ve master to work? I thought your supposed to log for 15-20mins then put the log in ve master and load the new tune. I don't know how my car will act in sd mode much less driving it around for 20 mins like that. I'm going to get a new log here in a bit. I'll send it to you if you want to take a look at it.

Appreciate the help so far btw...
Thanks

C_Rules

iTrader: (7)

technically it does not but if your maf is working it is influencing your fuel trims. ve master is used to get your ve tables in order. if you're trying to get them in order while the maf tables are also making adjustments based on the afgs you're not going to get the best results.

sd mode is nothing to be scared about. if the car is lean in sd mode just don't get on it. another thing to watch for is split blms. if your banks are too split you need to adress that before tuning the ve tables.

1BadZ95

Ill give that a shot. As for my a/f. I went back and looked at what we changed the other night in the RPM vs afr @ wot and for some reason the numbers were positive when they were supposed to be negative. So it was throwing even more fuel in there. I changed the numbers back around and my a/f went from 10.0's to 13.0's. lol That the most progress so far. I backed down a bit more tryin to get it in the 12's. I did notice though when I have the A/C on at WOT the a/f is 11.2-11.5. With the A/C off its 12.8-13.4. Why's this?