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ritzy240sx
09-04-2004, 01:00 PM
I was just wondering if anyone elses rpms were like 1000 rpm off from the safc to the tach. at idle it was only 500 off but as the rpms went up the gap got bigger. I was wondering what wire people were using for their rpm signal. I used a yellow wire with red stripes

Also I'm running a t3/t4 w 555cc injectors and a z32 maf and when I started to hit full boost around 4000 rpms my car would stumble and backfire eventhough I was adding +30 fuel. does anybody know what this problem could be?

SPLzero
09-04-2004, 01:59 PM
I was just wondering if anyone elses rpms were like 1000 rpm off from the safc to the tach. at idle it was only 500 off but as the rpms went up the gap got bigger. I was wondering what wire people were using for their rpm signal. I used a yellow wire with red stripes

Also I'm running a t3/t4 w 555cc injectors and a z32 maf and when I started to hit full boost around 4000 rpms my car would stumble and backfire eventhough I was adding +30 fuel. does anybody know what this problem could be?



your car wont run 100% untill you are tuned.

the Tack is off on your car. i had the same problem with mine. my tack is was % off so as the numbers got bigger the gap got bigger. just make sure its set for 4 pistons and not more or less.

Hugh
09-04-2004, 02:09 PM
I was just wondering if anyone elses rpms were like 1000 rpm off from the safc to the tach. at idle it was only 500 off but as the rpms went up the gap got bigger. I was wondering what wire people were using for their rpm signal. I used a yellow wire with red stripes

Also I'm running a t3/t4 w 555cc injectors and a z32 maf and when I started to hit full boost around 4000 rpms my car would stumble and backfire eventhough I was adding +30 fuel. does anybody know what this problem could be?




HOLY SH#TBALLS!! Adding 30% fuel at 4000rpm?? No kidding its going to backfire and stumble. You're pumping way to much fuel into it. Back that way down and it will smooth out.

Do you have something that reads air/fuel ratio in your car? Tuning without A/F is like beating your head into a wall.

ritzy240sx
09-04-2004, 03:03 PM
I just have a a/f ratio gauge. but as the rpms would climb from 3000 to 4000 it would go from rich and then jump over to lean when it started backfiring. I retarded my timing as much as I could but that still didn't fix it. I was thinkinking it could be my fuel pressure regulator but I ajusted it and still nothing.

Hugh
09-04-2004, 04:24 PM
OK, retarding the timing really far, then dumping a bunch of fuel in = engine doesn't want to run. It sends unburned fuel into the exhaust manifold and it explodes there. (hence, backfire)

What type of A/F gauge are you using to tune with?

ritzy240sx
09-04-2004, 05:16 PM
I just have a narrow band o2 sensor. I also tried putting the correction to 0 and still the same results any idea what this could be?

benevolent
09-04-2004, 08:15 PM
how much pressure are you trying to stuff in? and did you upgrade your pump>?

DeatschWerks_Dave
09-05-2004, 04:18 AM
as far as your tach, my analog tach is much slower reacting than the safcII tach. If I accelerate slowlwy, they don't differ that much. If I accelerate quickly, my analog tach can't keep up. Most likely the safc tach is the one that is correct.

hey808
09-05-2004, 09:24 AM
I just have a narrow band o2 sensor. I also tried putting the correction to 0 and still the same results any idea what this could be?



You really should be tuning with a wide band O2 sensor. The narrow band gauges are not good to tune with. It will only tell you really rich, or really lean, and nothing in between. You shouldn't be addinf fuel with the bigger injectors with the safc. If anything, it should ce in the negative range.

PR_S14
09-07-2004, 03:08 PM
I use the AFC2 for my 550's and at/above 4000 RPM I have -30%. Your car doesn't want to run cause it's too much fuel.