BudH

iTrader: (3)

I installed my MAFT today and the car gets 4 degrees of KR as soon as you floor it.

What is causing the problem?

Removing the MAFT fixed the problem, but I want to use the MAF Tuner for mixture control..

Anyone help.

With MAFT = O-2s between .870 and .930 . KR 4 ful degrees

MAFT Removed, O-2s between .870 and .920'

Help!

WS6 GreeN

How did you go about arriving at your O2 readings? Did you tune the BASE first to get it slightly negative and then work on the WOT?

BudH

iTrader: (3)

I started the night last night at 10 % rich base and -2 %wot. L Trims were around zero. Moved to 15 % Rich base and 0 % wot. Then moved to 15 % rich base and +2 % rich wot, followed by +4 % rich wot and then +8 % rich wot. I had 4 degrees knock retard instantly when I went wot and for the entire 1/4 mile run. Mixture adjustments didn't help at all.

I removed the MAFT and KR went to almost none in 1st gear, 2-3 degrees in 2nd gear, and then tapered off in 3rd to about 1 degree at the end of the 1/4. O-2s were actually reading leaner with less knock retard!

Also, this is on a 98 Camaro SS with headers, ported maf, ported throttle body.

Anyone that can help, please do!

Thanks

CAT3

iTrader: (9)

Running to rich can cause KR, as well lean. When you installed the headers you probably are running rich, as most have the O2 bungs in the wrong location, making it harder for the computer to correct. You said you had KR at +8, did you check all the other settings to see if KR was there also? Factory O2's are as reliable as a crackhead. Mine were 915/910 WOT and the wideband showed where it started at 12.8 and continually dropped to 11.9:1 without the O2 changing at all!
You also said the JR was still there after removing the MAF-t, so was it or not? You said it also cured it after removal, you mean it was reduced?

Black LS1 T/A

If you get 4 degrees of KR as soon as you floor it, straight across the board, there's no telling how much is really there. In my stock program, the MAX KR / PRM is 4 degrees.

Orange Krush

In your opinion where is the correct location for the bungs to be welded?

MIGHTYMOUSE

iTrader: (59)

leave it off, your wot a/f is fine, if it gets wrong, then worry about it.

BudH

iTrader: (3)

Cat3,

With the MAFT removed, I had some KR, but not 4 degrees across the board.

CAT3

iTrader: (9)

Orange crush, "exactly where" I say depends on each brand of header, but my jet-hots could have been upstream about 4in or more, so they would read the same as the manifolds did, that was my point. If you put headers on a carbie, you normally add fuel as they lean out a little, on our cars the cimputer looks for the O2 readings to adjust in closed loop, but with them downstream on some cars the readings are a little off. Just my .02 after installign then Widebanding my car pre/post headers.

BUDH, see about getting a WB reading. I used my local shops, hooked it up and drove around big difference from what the O2 looks like.

Slowhawk

iTrader: (12)

Sounds like rich KR to me.I would put base to 10% WOT to 0% and put some miles on it.Then tune in WOT.My 02 readings are .87 on A-tap.
If you change the base setting,then make a pass the computer had no time to learn and is dumping fuel and pulling timing because it senses something wrong.

BudH

iTrader: (3)

I had 4 degrees KR at every setting at WOT. That's why I started messing with the WOT setting. LTRIMS were pretty close at that point.

I also drove about 50 miles with the MAFT on at 10 % and -2 before starting messing with #s.

I am restarting the process and gonna see where it goes.