Whats up guys, just resently installed some new mods on my truck(92' 350), i have a 50mm tbi with spacer, k&n intake, msd ignition and coil, headers, 3in exhaust all the way back, also fuel pressure guage and adjustable regulator. I just recently installed an air/fuel ratio guage, it shows i am idling very rich, is this common with tbi's? I have adjusted the regulator from 13- 15 psi, but no luck stopping the rich idle. Let me know i you guys have any possible solutions. (also have cam, heads, and strocker kit waiting to be put in)

 

consider replacing the 02 sensor with a quality GM ? does the exhaust smell rich ? my NB A/F gauge runs a bit rich and it is a bit rich 122 BLM at idle(OL). that is purposeful. i wasted $50 on gauge BTW. i wonder if you are in OL at idle as the 02 is not getting enough heat? maybe a heated 02 ?

 

i just replaced the o2 sensor about 2 weeks ago, this didnt change my rich condition, but only made my a/f guage go up and down more eratic than usual while at crusing speeds. i just might have to try a heated o2 and see if that works.

 

if you a/f guage is hooked into a narrow band o2 sensor, at cruise it should be eratic, it should jump between rich/lean.

with your modifications, I assume you upped the fuel pressure a bit, since the idle VE probably was not changed much at all, or it may have even gotten worse (the small stock exaust manifolds probably actualy got the exaust out better at idle/low RPM's, then the headers do), the upped fuel pressure will account for the rich idle condition. This SHOULD make itself erratic as well, once the car is warmed up.

What you really need to do, is get a WB02 unit, and get into properly tuning the car. Then when you new cam goes in, you won't be entirly screwed.

 

i would really like to get into computer tuning for my truck, all the extra hp people are getting from tuning is great. I know when i put the cam and heads on i'm going to be screwed, just becsause the cam says computer compatible, doesnt mean its going to work, most never do with out tuning.

i have been looking at the diy-tuning board, but some of this stuff i still dont understand, like what components i need to burn my own chips? i not a very computer friendly person, my knowledge on this stuff is minimal(and yes i have search, but havent found the info im looking for), any advice on a started kit, or some of that sort would be awsome, i just want to know the basic components i need to do this, thanks guys!

 

When I get some time, I'll search thru some of my old posts. About 6 months ago, I lined out everthing needed.

 

awsome thanks man

 

The FAQ sticky at the top of DIY PROM has everything you need except a link to Moats.net as an option for the hardware. I got the information from the FAQ, bought my hardware from Moats, and had my first custom chip (with stock bin) running in a single weekend. Now to finish of the last mods to the TB today and then settle in for some real tuning...

 

Bluechevy,

Check out this thread.

https://www.thirdgen.org/techbb2/sho...ghlight=Moates

 

thank you Dewey316, that clears up most of the qestions i have,
but one more thing, what else would i need in order to tune while driving? and are these chips reprogrammable or is it one time use?

thanks for the info.

 

With the moates adaptor, the chips are reprogramable. You can't really tune while you drive, you will need to datalog, then edit based on the data, burn a new chip, then datalog and drive again.

You might also want to read about the new Embedded Lockers Board, there is a huge thread in the DIY board. That peice make a huge diffrence in the way we tune!