Quick Scanmaster Help

[rking]

I just got my car together after a year and i have a couple of quick questions regarding what my scanmaster told me. Right after I started it at idle the BL was right at 128, however after it warmed up the BL stayed at 152, is this normal and is this rich or lean? Also under about 15 lbs of boost my O2 were at 820 to 860, is this rich of lean? I cant find the papers over the scanmaster and any help would be great, Thanks.

 

[TurboDave]

Originally posted by rking
I just got my car together after a year and i have a couple of quick questions regarding what my scanmaster told me. Right after I started it at idle the BL was right at 128, however after it warmed up the BL stayed at 152, is this normal and is this rich or lean? Also under about 15 lbs of boost my O2 were at 820 to 860, is this rich of lean? I cant find the papers over the scanmaster and any help would be great, Thanks.

If all you did was sit in the driveway and watch the BLM's and you saw them move up to 152 after it warmed up. That's fairly common in many of these cars. Can't explain why it does that when just sitting in the driveway, but if you take it out and drive it around on the surface streets for a few miles, where ther's stop lights etc. I think you'll notice the BLM's at idle, while sitting at a stop light might be somewhat lower.

As for the O2's, IMHO, those are good safe numbers for 15# or less of boost and in street trim. Lot of folks will tell you that high 700's is best. NOT ME. not in street trim, with pump gas. The best numbers are in the 820's.

 

[TurboBob]

Idle BLM's

Idle BLM's can be higher after a long idle because the O2 sensor cools off. When
the sensor is barely warm enough to keep the loop closed it has a hard time
swinging rich, but swings lean easily. This causes the BLM's to march steadily higher.

After market A/F gauges (Cyberdyne, etc) can make this situation worse.

Air leaks in the exhaust can make the situation worse.

Anyway, the bottom line is that your situation is essentially normal. The O2's
will go 'way up' right after you punch it but will 'settle' some in third gear. This
is even more true with non-heated O2 sensors.

I agree with Dave that 800+ is best on the street, generally.

TurboBob

 

[rking]

Well the BLMs went up to 152 after a 15 minute test run up and down the road. When I got back to the garage after driving I saw it was at 152 and it never came back down. Also is this rich or lean?

 

[sam87]

blm = 152 indicates lean.

 

[1badTTA]

blm = 152 indicates lean.

indicates lean and the computer is adding more fuel to compensate. I also have this problem but mine can be explained by a rather large exhaust leak on the crossover pipe, the rest of my BLM's are rather normal (118-138).

 

[BlackBeauty]

What does BLM stand for? Thanks.

 

[TurboRegal84]

Originally posted by BlackBeauty
What does BLM stand for?

Block Learn....it is a basic way to tell if the car is running rich or lean....

The lower the Number the richer it is (PIG Rich is around 105) Lean is the higher numbers (Lean is about 150)