02s & BLMs

[Paul Clark]

Took the car out for a little testing to see if I had improved the knock situation. It's better after replacing the vac. block gasket and sealing the nipple on it for vac. brakes. Zero knock at gradual accel. to 18 lbs.. Red lights on the gauge when flooring it in 1st, but 0 knock recorded on SM.
When I got home, at idle the 02s were mostly below 100 and the BLMs were at 115.
What does this mean and where should I look next?
Eric's alky chip.
Thanks

 

[Razor]

This may be better handled by Eric.. my thoughts are if the BL is 115 at idle, it means your a little rich on the and the computer is pulling a little bit of fuel. Now if you drop your fuel pressure a little, like from 43 to 41.. the idle cell BLM should increase a few numbers. To me anything +-10 from 128 is fine.

I dont pay attention to O2's at idle. As the chip may block it from reading correctly.

Pay attention to O2's at WOT.. and after you stay in it at WOT. They should gradually come down. Adjust boost/fueling you correct them.

HTH

 

[Paul Clark]

Sure is cool the way that Razor is always willing to help out.
Wish more businessmen were like that long after the sale.
Now that I've buttered him up
Is this even possible? -
Car is way rich (chip, FP, whatever) but it has some vac. leaks.
Because it's rich and has some leaks, they cancel each other out and the scan numbers are okay and it runs great.
Then the vac. leaks get fixed - and the car runs poorly because now it really is rich.
Or would re-setting the computer just compensate for all that?
Hey, at least I'm thinking a bit. New experience for me.
Thanks

 

[Eric Stage I]

Do you have a stock MAF, or Translator setup?

If a Translator, set the BASE setting to the leaner setting. Which will also help bump up the BLM's. Reset the computer when you do it.

If you have stock MAF, check if you have 2 screens, if yes, then take 1 out. That will usually lean out the idle a little bit too. If you only have 1 screen, don't take it out.

As Julio said, don't be afraid to reduce fuel pressure. Just watch for knock, etc.

On my chip, usually the idle O2's will end up around 750-850 once open loop turns on. You might even try a new O2 sensor (if you haven't already).

Eric

 

[Razor]

Sure is cool the way that Razor is always willing to help out.
Wish more businessmen were like that long after the sale.
Now that I've buttered him up
Is this even possible? -
Car is way rich (chip, FP, whatever) but it has some vac. leaks.
Because it's rich and has some leaks, they cancel each other out and the scan numbers are okay and it runs great.
Then the vac. leaks get fixed - and the car runs poorly because now it really is rich.
Or would re-setting the computer just compensate for all that?
Hey, at least I'm thinking a bit. New experience for me.
Thanks

Man if it runs poorly.. it runs poorly. You need to systematically go through all the little details to get a properly working engine. Its all the penny's that make the dollar.. heard of that

If you have vacuum leaks, the BL's will be higher. Higher BL's means the ecm is adding fuel to compensate for extra air

New AC Delco AFS 20 O2 sensor? Or old original one :redface: The I replaced it 6 months ago dont count cuase the car was running poorly.. running poorly takes out plugs and sensors.. like the O2.

Just fishing.. lots of fishing when trying to sort out problems.

Good Luck..

 

[Paul Clark]

Jeesh!
You can't find good help on this list anywhere.
You buy the product, then it's just "See ya - You're on your own.":wink:
Many thanks to both Razor and Eric.
Would it make sense to take off my HD actuator and put the stock one back on while I'm in search of my knock gremlins?
I know I'll find them soon, but it would be an easier search at lower boost levels. I think. ?????
Thanks again.

 

[Razor]

Would it make sense to take off my HD actuator and put the stock one back on while I'm in search of my knock gremlins?
I know I'll find them soon, but it would be an easier search at lower boost levels. I think. ?????
Thanks again.

If your knock is real, not false.. absolutely. Keep the boost turned down till you find the culprit.

 

[Paul Clark]

Set the base setting on the Translator (3") to 5.
After an hour's worth of driving at a bunch of different speeds with FP still at 43, the BLMs are at 129. I'll take that.
Still chasing knock, but have a few more things to try.
Going back to a hotter plug and will raise the boost just a bit.
Might not make sense, but the car liked it before.
I should never have painted those valve covers.
Thanks again, guys.

 

[Razor]

Now that you mention valvecovers... is your engine wire harness secured by a bolt on the back of your intake, or do you have it resting on top of the knock sensor .. I've seen a few cars with the wiring harness laying on top of the knock sensor.. cuasing it to bang against it when the motor tq's over.

Just fishing for ya

 

[Paul Clark]

Amazed by the help available on this list that is given so readily.
I'll check out the harness tomorrow, Razor.
Have received lots of help from you, Eric, Brian the tranny guy, and many others.
Wish I could give something back.
Here's what I have to offer so far -
Turn the key clockwise when you start the car, only after making sure the battery cables are connected. :redface:
Thanks