ok, the new motor seem to be running good, but i just want to see if one thing is right. i have a narrowband o2 gauge (i know its not accurate, but it still gives me a general idea where im at). what i am reading is the 2nd and 3rd green bars (rich) stay lit during idle, after the car is up to operating temp. is this normal? the motor only has about a 1000 miles on it. the car has a bunch of aftermarket parts and mods. headers, no cats, custom exhaust, rb flywheel, act clutch, tb mod done, cone filter.

also, one of my port actuators seem to be frozen up. how can i fix that? just spray a little pb blaster on it? any help is appreciated

 

can this be brought down to stoich by adjusting anything i currently have, or am i going to need a seperate fuel control unit?

 

It's normal IF you don't have a airpump and working acv on the car. If you have a airpump and working acv on the car, then it's not normal.

A working airpump with working acv will inject air into the EXAUST PORTS which are located before the O2 sensor, therefore making the 02 sensor read LEAN. But if you do NOT have a working airpump and acv, then the mixture will most likely read LEAN.

If you have a airpump on the car and a working acv, and it reads rich, I suggest the ACV OR the two vacuum signals to it are not working and letting the air from the airpump dunp overboard thru that large airhhose at the bottom of the ACV. Dumps into the silencer in the right hand fender up front. Near the washer bottle/motor.

 

Sounds right for a car with no ACV or airpump.

You won't be able to make the car idle very well close to stoich. These cars like to idle around 12.5 or so which is of course a little rich.

Freeing the actuator can usually be done by using a LIGHT penetrating oil like WD-40. Using something that sticks around like PB Blaster will just make them clog up faster in the future. If you cannot free the ports from the outside, you will need to pull the lower intake.

 

yep, forgot to mention the air pump is removed. would it be recommended to get an aftermarket fuel controller to fix this? will there be any performance gains, or should i just leave it as-is?

 

I got my SAFC hooked up last week and tried to lean out the idle. I was able to pull 4-6% off of it and keep a nice idle. Anything more and the idle would stumble and sooner or later the car would Stall. Only problem with the leaned out idle, is that it would not stay running during a cold start. So back to normal it went.

Without working ACV (unplugged) and no air pump, Mine reads 1-2 greens rich.

Acclerating full throttle, at the top end, my **** still reads in the blue rich, and I've pulled the top end down 6-10% from 4000 up.

 

i have no experience with any aftermarket fuel controllers. with the safc can you program it to stay the same at idle, and less fuel at higher rpm's?

 

There's no "fix" as this behaviour is by design.

However there is a gain in getting a fuel controller such as the S-AFC. It will allow you to tune your fuel delivery (likely leaning it out quite a bit) for a little extra power and some fuel savings.

Yes. It allows you to tweak the fuel curve based on throttle position and RPM.

 

Yes. I actually added fuel at idle with the SAFC, it seems happier. I think I'm running +10% below 800 RPM. I just try not to idle in one place too long, my exhaust will kill small animals and stun humans.

-=Russ=-

 

so is the s-afc the unit of choice here, or are there any others worth looking into? price is a factor and safc's seem to be pretty reasonable.

 

For the cost, the SAFC-II is probably the best unit. The ignition timing isn't too bad, stock (though not great), but the fuel delivery is... awful. I've heard rumors of NAs going into the 9:1 A/F ratio at high RPM. The turbo guys don't go anywhere near that rich - and a NA doesn't need to be anywhere NEAR that rich.

-=Russ=-

 

An 88 model should have a VARIABLE RESISTOR to lean the idle mixture or richen the idle mixture. It can change the afr about a full point.

A SAFC would be a good tool to have to LEAN the mixture out, especially at high rpms i.e. about five grand or so (memory here).