Z28 Boy

i just got winaldl working on my car tonight...i have a lot of questions, but my main one is this:

everyone always seems to be talking about fluctuating BLMs...mine are at 128, and havent moved. i know for a fact that the car is running rich, so whats up with that?

arent they supposed to be fluctuating at least a little?

i did a quick search, and saw a few threads about locking the BLM...could this be what is happening?

any ideas?

-brian

hectorsn

If the car is in open loop, it will read 128 blm. Maybe the car is stuck in open loop. A stuck t-stat with cold weather might do that.

camaroguy99

Yep most scanner programs will have a flag that tells you when you have entered closed loop. If you have just started the car wait about another minute or so adn things should start changing even a little bit.

Look at the possible bright side. Your car is so well in tune that the BLM's are PERFECT (Not likely though)

Z28 Boy

what else could make it stay in open loop? just a stuck t-stat or cold weather? i think that may be my problem now that you guys mention it. it seems like it is "stuck" in the startup mode.

-brian

Z28 Boy

also, correct me if i am wrong, but wont the IAC constantly be "going" pretty loud in open loop?

when the car is at an idle, it is really loud, as if there is a huge vacuum leak...all you can hear is a hiss, until enough gas is given to get the RPMs up to a couple grand.

-brian

Matt87GTA

IAC... loud? Never heard of it. The IAC is constantly active in open and closed loop and will attempt to idle the engine at whatever the PROM cammands. You may want to check the minimum air setting of the TB if you are getting a really loud hiss from the air intake at times. It can be a ton of things, but checking the hardware first is always a good idea. There is a technical article on checking the min air and setting the TPS base voltage on this site.

What does the CTS data look like when it is acting up?

Z28 Boy

i was always under the impression that that article was for TPI, so i never read it. i will check it out and see if it applies to TBI as well...

-brian

V8Astro Captain

iTrader: (1)

Are you looking at this data at idle right after start-up. My ECM will NEVER go into closed loop no matter how warm it is, or how much the O2 is swinging...I havr to drive it before it'll go into closed loop.

Just a thought.

My IAC is loud as hell too when I first start the engine. It's open real far and that makes for a really loud hiss.

Here's how I set the minimum air. Get the engine nice and warm by driving it. Watch the IAC counts at idle...make a note. Then I stop the engine and turn the throttle stop screw in 1/4 turn and then drive some more. I shoot for 10-15 IAC counts at warm idle. The less the better.

Matt87GTA

Oh yeah, my bad. That article won't be much help aside from the actual idea. But Astro has a good plan there on adjusting the minimum air. And correct me if I am wrong, but there is no adjustment on the TPS for a TBI car, right?

Z28 Boy

yeah there is an adjustment on the holley base (which is what i am using) for the throttle body. but my TPS should be good...winaldl is saying that it is like 2% at idle, and about 100-105% at WOT.




well, haha, you have seen my other posts...what if i cant get the damn car to run well enough to even warm up? anyone live close to central new york and wanna come over and play????? i am looooooooooost.

-brian