ujslost2

iTrader: (27)

Tried to tune my car via speed density. Well i did a search and found all the tables i needed to adjust to start off with. I did that and flashed it and unplugged the maf. I took the car up the road and it just falls on its face and dies. I cant even make it out of the driveway. I have the ve table tuned for the maf plugged up, is there ne changes i need to make to it before trying speed density? Thanks

HumpinSS

iTrader: (1)

Check the HPTuners help file under the How too's section

P Mack

iTrader: (6)

I had to let mine sit for like a minute before it would even idle, then it drove alright. Your ve table could just be real far off in the lower rpms. You might wanna do the 60, 80, 90% thing to get it to run enough to get some logs.

WS6snake-eater

Do not disable code P0102. If you do, the VCM will think that the MAF is still plugged in and will not revert to SD mode. Did you disable P0102?

luv2spd

iTrader: (1)

Most likely your ve table is just so far off with the addition of your cam that it doesn't like the fueling it's getting. Try scaling the first three columns of the ve and try again. My car would want to die when coming back to idle when i started my ve tune. It's much better now.

Black02SS

iTrader: (36)

I just started my SD the other day and have no issues with idle. I put my VE table back to stock, open loop only, disabled PE, and turned off the SES lights for the MAF. I did not turn the codes off completely.

luv2spd

iTrader: (1)

Sorry to go off topic, but what's the advantage of doing the sd tune in open loop? What do you shoot for if you're doing open loop sd tuning? 450 mV??

P Mack

iTrader: (6)

The only real reason I would use open loop while doing sd tuning is so I could shoot for an air/fuel ratio other than 14.7, and only if using a wideband. That would come in handy to tune the ve table at high rpm, high MAP cells.

Black02SS

iTrader: (36)

The one main reason I am using open loop is because I am tried of dealing with these O2's and all the problems I have had. I am going to get mine dialed in for about 14.5 during cruise and then adjust the PE table for WOT.

Also, I wouldn't feel comfortable running open loop if I didn't have a wideband. I love mine. I feel much more comfortable being able to monitor my A/F ratio at all times.

luv2spd

iTrader: (1)

Oh, ok gotcha. Makes sense if you have a wideband, I was thinking narrowband like I have to use.

ujslost2

iTrader: (27)

Yes i did disable code 102. Do i need to just check "no mil light"? I will try this tonight. I have the ve table tuned fairly decent for the cam with the maf, so do i need to go back to my stock ve and scale the first three columns for speed density? Thanks for all the help.

ujslost2

iTrader: (27)

I changed code 102 and went back to my stock ve table. Car will actually stay running. But now i cant scan my fuel trims. What do i need to do? Im scanning dynamic airflow and dynamic cylinder air is there nething else i need to scan for my fuel trims? Thanks

Black02SS

iTrader: (36)

If you want to scan your fuel trims, you need to put the car back in closed loop. If you want to tune it with a wideband, keep it in open loop, dial your VE table in so it is at the correct a/f ratio, then re-enable closed loop.

ujslost2

iTrader: (27)

So if i dont have a wideband i need to tune speed density by using my fuel trims?Thanks

luv2spd

iTrader: (1)

That's correct. The 02s are very accurate at 14.7 so you can use the trims to tune sd for part throttle.

jimmyblue

iTrader: (11)

You can also bypass the whole trims angle and use O2 voltage
directly by forcing the car into open loop. Without the closed
loop trying to dither mixture around the O2s will tell you rich or
lean and, if you're close, even a little about how much. If you
put the closed loop enable temp high, and lock out the PE mode
(like TPS%=100) you can drive around and pull the O2 voltage
histogram, increase VE by 1 point if it's below 0.3 and decrease
if it's above 0.7 and leave alone if between the two. Take a
few passes to get right, that way, might want to do something
like <0.2 +3, <0.3 +1, >0.7 -1, >0.8 -3 etc. This will not be so
easy to do when you are at the higher MAP levels but MAP is not
really a big player, if you can get low to mid-MAP right and just
follor the usual MAP-wise profile that will be really close.

I wrote a "debug tune" for a guy that made the changes I
described, and had him run logging pulls with it. A couple of
turns through the updating drill and I got to a very different
looking, but much better driving, VE table. Have a look:

ujslost2

iTrader: (27)

So what your saying is stay in open loop and tune by my narrowband histogram?

HumpinSS

iTrader: (1)

Jimmy, magnus and horist are the smooth ve table kings.....

jimmyblue

iTrader: (11)

Yes, that's the way I went about it. Other guys are
using closed loop and STFT averages, I'm not sure if
there's any practical difference to it, maybe you avoid
having to apply a funky debug tune to get the data.

Ummm... I'm not the king of anything (but at least
nobody thinks I'm a queen). Just captain of my own
ship, a compass that often works and a couple of
tales to tell.

ujslost2

iTrader: (27)

Ok i will try this method and see how it works for me. I will let you know. I appreciate all the help from everybody.