how do you adjust the air/fuel mixture? how to tell if its rich or lean?
 

thread title is the questions... the car bogs really bad and i want to think its because its dumping to much fuel into the car (did the TB mod and messed with the screws up afterwards trying to adjust the idle) i also want to know how to adjust all the screws to spec on the TB... is there a diagram to go off of or a how to set it in the FSM i cannot find it.... after putting on a new fuel filter it got worse so i know its to much fuel and not enough air so i got to figure out why its doing that.... thanks in advance

christopher

You can adjust the "IDLE" air/fuel mixture by turningt the variable resistor screw, it's on the strut tower beside the pressure sensor, it should have a L and an R on it to symbolize..........Besides that it sounds like a tps adjustment is in order, search for "tps adjustment 101"

ive been playing with the TPS for days now and still no luck... its on the 1.0 volt and then damn it goes all over the place after a while.. i know its hard to find its happy place but good god nobody else had this much flunctuating with theirs

btw i thought that was the TIMING is it not?

Using test lights or voltage at idle readings will get your idle setting done, but may not show a worn out TPS resistor.

Try this:
Pull the TPS connector off.
Get an analog (needle type) VOM set to the 1K scale.
Connect it to the pins for the orange & green wires.
Open the throttle enough so you can test the TPS plunger through its full stroke.

The reason is because as the TPS wears, it can give non-linear or inconsistent signals to the ECU.
You can see this as you work the TPS plunger in & out, the meter needle should swing smoothly from ~0 to ~5K ohms.
A worn out TPS may give 1K ohms at idle, but have a drop out or short further up the scale.

A drop out at mid scale will tell the ECU to idle at that point & give a fuel cut.
I had one go open at the top which made the S5 ECU go nuts, giving random fuel cuts.

you say it gives fuel cuts right... it seems to be getting too much fuel.. is that a symptom of a bad TPS? ill try that tonight thanks sureshot

What do you mean by "bog"?
Are you romping on it under 3kRPM?


-Ted

The TB mob can cause a small stumble if you open the throttles too quickly at low rpm, but if it's really bogging badly that's not the TB.
It is in the FSM. There's a whole section on setting the TB starting on page 4A-55.

thanks nz conv ill download that one tonight

I just did the TB mod myself and i had the same problem. If i "got into it" it would kinda stumble or bog, but if i back-pedaled a little or feathered it it would smooth out- My TPS was reading 1.92k, i adjusted it (had to do it a couple times to get it smooth) and now its at right about 1.02-1.10k ohms. Smooth as a baby's ass.

-now if i can just get it to idle:(


check this out too- gives good info-
http://fc3spro.com/TECH/HOWTO/TPS/tps.html

well rx-rated i had a bad idle problem but i fixed it by adjusting the throttle stop screw.... i have it idling from 750 to 1k rpms... if you dont understand what i mean ask me and ill take a pic of what i did to adjust my idle but after that i mean the car just dies... and i think its because its not getting enough air... i have some working to do on it blah

Hey, thanks! I know exactly what you are talking about, i spent quite awhile working on my idle problem. i am pretty sure its vacuum related. damnit

i was wodering if this is the same for the s5 because i am having trouble locating it
thx

since were on the subject of idle mix screws and stuff... what is the screw on the mass air meter. i know it has something to do with the signal that it sends to the ecu but what is it? guy had it befor me fittled with it and ive made it idle ok but not the way it should.

chris

p.s. not meaning to hi jack the thread.

The only way to get to the screw on the AFM is to remove the protective black case. It adjusts the AFM's curve. If it has been screwed with, you need to set it back to factory specs. Not sure if this is in the FSM or not...It may be cheaper/easier to get a used AFM and replace yours.

To the original poster: there is no way to adjust the A/F ratio except at idle. Normally, you do NOT need to touch this adjustment unless it has been messed with. Trying to adjust it to solve other problems is the wrong way to go....