Tired of running rich, i think

[SpoolinUpGN]

i FINALLY got a scantool. i know, but, college = no money. I'm pretty sure the car is running rich and it also has a somewhat rough idle. these are the problems i'm tryin to target with the scantool besides just making it run well.

According to the scantool, O2's at WOT will hit .850+, recall showed a high of .867 on one run. I know O2's dont tell the whole story, so what other numbers should i grab and at idle, cruise, or WOT to help diagnose the problem? I'm claiming these are rich numbers because i thought these were supposed to be in the .750-.780 area. Oh, and at about 16#, no knock at all even on the shift.

Thanks to all those who repeadedly answer these questions for scanmaster newbies

 

[jdpolzin]

WHat are your BL numbers? You should be running at 128 ideally at idle. You are likely to be running much higher. I am in the process of chasing the same problem. Bl's were at 150 and the was smoking like crazy. CHanged all rubber vac lines and MAF and now I am at 137. Got to still keep going though. Welcome to the new battle!! :tongue: -----Jeremy

 

[SpoolinUpGN]

So i finally decided to record some of the information the scanmaster gives me and i'm still curious about whether or not i'm really running rich or if the car needs a good tune.

Numbers for the car are as follows:

02: jump around at idle, but i've seen everythin from 800 to 867 at WOT
L8: 38 at idle to about 90 while driving, bounces around
BL: 105 at idle, go up to about 130ish driving normally (shud i get WOT #'s?)
TPS: .46
CLt: 160
ATs: 63
IAC: 42
AF: 09 (idle)

I'm not totally unhappy with how the car runs, i mean it holds 17# with only 0.7 degrees of knock on the shift. It goes good but any tuning possible would be great.

Oh and i have a 93 octane chip from Cotton's and 42.5lb/hr injectors.

Thanks guys,
joe

 

[jdpolzin]

Your Blm numbers at idle is a little low. Ideally you should be around 128. This could be a chip[ issue. Maybe contact Cottons and ask them what they are setting their chips at. With a low Bl number like that, your computer is thinking you are running rich and tries to lean it out by dumping less fuel. The running numbers are a little high. Mine runs about 110-115. I am chasing my BLM problem, it is at 150 at idle. Have you changed your PCV lately? Try to Duetsch number 162 from AutoZone. Do you run a check valve in the PCV line that goes to the vac line?

 

[SpoolinUpGN]

I'll give Cotton's a call and ask why that number might be low with the chip I have burnt, thanks for the idea.

Back when the car needed a bit of mechanical fixing, I had a lot of work done to the car at once, including a pcv check valve that ATR used to carry. I'll try to get a bit more info about that and get back to you.

Would changing to an AFPR help anything out? or should the 237 do ok? And, if i understand what you replied with, the car is running lean, isn't it? In my opinion, the smell would make you think it was running a bit rich.

 

[norbs]

I know you have no money but get yourself a wideband lm-1 otherwise you wont know if its rich or lean. Your scanmaster o2 numbers are dependant on exhaust gas temperature and basically useless for tuning, the stock narrow band sensor is only accurate 1 point either side of 14.7. Sorry for preaching , but other wise your never going to know whats going on. It will be the best $349 you spent in your life.

 

[jdpolzin]

The best way to describe your BLm numbers is " The higher the number reads, the leaning the computer THINKS it is running" therefore, it tries to make up for the lean readings by dumping more gas, which intern would make the car run rich. In your case, your computer is actually leaning out the fuel. But you are still running rich "by the smell of things." I am tired of battling my car. I just took it to get re-painted so I wont be able to play with it. One thing you could do is try tightening the intake bolts. An intake leak may cause this too. Most of the advice I am giving you is passed on from what I have learn chasing my issues down. :biggrin: