OK i thought i had a ground issue, well.. i cleaned up the 2 ground spots by the shock tower . and DO NOT ADD a ground to the boost sensor on the 88 model it will not start at all. anyway the orig. problem was the hes. @ or around 3500 rpm, 4000 power back . now is feels very bouncy, studdering around 2500 - 5000.
Could this be sec. fuel inj. problem ??. 88 N/A 13B Steert ported. i have read the tec. Stuff on it and im still stuck its seems like it gets worse everytime i DRIVE her. any sugg. Please HELP.............

 

What color wire did you ground from the pressure sensor?

 

Brown With White stripe ... it was already grounded BUT i noticed the wire was broke so i cut out stock wire harn. and went back with single spade connects. did them 1 at a time so i would not misplace a wire. went to start .. cranked i noticed the tac was not bouncing thought i hit my fuel cut off switch but i didnt. took anothe look on what i did unbolted the grounded spot and she started

 

Brown/White wire connects to pin 2A which is the Vref which powers up a series of the sensors. This is not a ground wire and the voltage in the wire should be about 5 volts w/key to on.

 

ok... there are brown w/ red stripe , black w/ white and solid black what is the right 1 to ground? also i noticed af meter is bouncing from rich to lean (like a heart beat) at 2000 rpm when held steady .

 

Solid Black is the ground.

 

In general, black is ground, and black/white is 12V, but there are exceptions. If you grounded a powered wire, you may have shorted the pressure sensor or other sensors out.

You can pull error codes, and test various sensors at the ECU to make it easier. There is a table of values in the Fuel and Emissions section of the FSM. I'd post a link to a code-pulling write-up, but the one I had is gone.

 

^http://fc3spro.com/TECH/HOWTO/ERRORC...KI/zerror.html

 

thanks 4 the info def. will have to check out

 

Thanks, satch. I put that link and one for S5s in the FAQ.

 

all sensor check out good nothing shorted safc shows sensor voltage ... ecu not throwing any codes im assuming they all are good. ..... still getting a studder in low rpms watching afr meter lights switch from lean to rich ( like a heart beat). secondary inj feels like its operating .
Could it be something easy like fuel filter Any1 know.
Thanks RotaryRocket88 and Satch for the info.

 

The secondaries will only come on above 3800 RPM, and right at about 0 manifold pressure. In other words, you have to be giving it a decent amount of throttle before the ECU will transition. The engine will make it to about 5-6000 RPM on primaries alone if you're only giving it partial throttle.

Do you have a wideband gauge, or is this a narrowband? Will it drive smoothly if you accelerate with very little throttle? You mentioned an SAFC, what fuel changes have you made?

 

car was bought from prev. owner , looking through old records on car i dont see anything on injectors installed, but i do remember him saying something about increasing them. IS there a way to tell? when i drive the car and acc. smoothly i get some studder. hold throttle in low rpms af meter goes back and forth from lean to rich sometime drops off the meter (wont display) WOT i get the hess. Proly from the grounds, but somethimes studder id say 4.5 - 6K , 6 on up to 8 good. Its hard for me to discribe cause its allways diff. as for wideband , or narrowband i dont know lol. its a 20 LED auto meter AF meter

 

Your gauge sounds like a narrowband, which basically means it's giving you a very rough estimate of mixture. A wideband gauge will show you a number between roughly 10.0 and 20.0, but some also have colored LEDs. It's normal for a narrowband to bounce back and forth between lean and rich if you're cruising (closed loop, O2 sensor input used by ECU), but if you're trying to accelerate at all, it should hold fairly constant.

Stock 460cc injectors have a red-orange colored top (sometimes they can look a little red-purple). If they're light purple or tan, someone put 550cc TII injectors in.

Again, what corrections have been made with the SAFC?

 

i added a ground to the pressure sensor and mine works fine. i made sure i knew which wire it was before i did this though.

 

Again, what corrections have been made with the SAFC? .......... sorry man kinda new to this tec stuff. what do you mean by corrections? your info is much app. And i think the injector are stock by the color you descibed. i will look more into today. thaks again

 

high 1000 - 10% 2000 -8, 3000 -4, 4000 -1, 5000+2, 6000+ 5, 7000 +5 8000+5
Low 1000 - 5, 2000 - 2, 3000 =0, 4000 + 2, 5000 +5, 6000+5, 7000+5, 8000+6
im thinking this is what you mean , anyway this is still new to me i play with the values but dunno what they mean. does this map make any sense or i just dont know WTF im doing lol..... thanks again RotaryRocket88

 

Every % change is an increase or decrease in fuel delivery at a specific RPM & throttle position (low or high). Are these settings the previous owner had, or did you adjust these? If it's something you want to keep, write the settings down (or save if possible on an SAFC). I'd suggest bringing the corrections to 0 to see if things improve. That -2 to -10% from 1000-3000 RPM at low/high throttle is pretty funky.

 

i brought the values down to 0 still no change on how its drives im stumped going to change out fuel filter ( never had i in the 7 years i owned her )