Idle problem. 115 BL, 950 o2 and 18.0 wideband?

[LEGACY_GN]

Any throttle brings BL up but idle it's running rich as hell. Replaced IAC, nothing changed. New o2 comes in today but I"m thinking might be stuck injector? They 60 pound and are 7 years old. Have checked all hoses and intercooler pipes. No leakes. Has bailey tr6 which is about 4 months old so ignition is good. z06 mass air is about 5 years old so maybe that but then it would be all the time, not just idle, right? What really confuses me is the wideband reading lean.

I ran about 10 pounds of boost with quick burn out from stop light, left off, had a backfire in the intake and then it started. Drove it home fine. Just doesn't idle.

 

[SHADOWII]

When adjusting the iac, did you remember t0 adjust the tps at the same time? It's often forgotten the one effects the other.

 

[LEGACY_GN]

TPS is right on according to scanmaster.

 

[TurboBob]

what chip, what wideband?

hose blown off the MAP sensor ?

vacuum leaks generally cause the BLM to climb at idle. An intake sneeze could have hurt the MAF sensor.

time to visually inspect everything for blown/split intercooler hoses, vacuum lines (like to the fuel pressure regulator), etc.

Bob

 

[LEGACY_GN]

Turbo tweak 6.1 and aem wideband. I triple checked all the intercooler lines and vacuum hoses. No leaks. Map sensor still connected but maybe got damaged from back fire? What I don't understand is why it's running rich according to BL and O2 but the wideband is reading lean. Is my O2 bad? I have one ordered that should be here this afternoon. If it's not that it must be a leaking or stuck open injector, right? Or maybe bad MAF. Am I missing anything. Any way to test MAF?

 

[TurboBob]

the only real way to test the MAF is swap in another. Unless the MAF is completely dead. But you would have trouble codes for that.

What is your MAF reading at idle? You could try unplugging the MAF and see if the car idles/runs better.

Bob

 

[LEGACY_GN]

45-55 on maf reading.

 

[TurboDave]

45-55 on maf reading.

At idle???? Are you sure you're not reading the map???? the maf should read 5 or 6

 

[TurboBuRick]

Its not rich. It's lean. BLM is adding fuel when the number goes above 128. The wide band is further indicating, your lean. Sounds like something blew off or the maf crapped its pants.

 

[TurboBob]

the stock O2 is pegged rich, which is why the BLM bottomed out.

So, something is lying. If the stock O2 blown/maxed (never seen it happen this way, but who knows) that would explain things. If the MAF is reading too much that would explain the O2 and BLM, but not the wideband.

blown fuel pressure regulator could be dumping fuel thru the vacuum line, and cause the rich O2 and BLM, but not the wideband.

I guess the one failure that could cause all this would be a stock O2 stuck at max.

Bob

 

[LEGACY_GN]

Fuel Pressure is reading normal on my hood gauge. Rick, my BL is 115, which is rich along with o2 at 950. But wideband reads 17 to 18 on scanmaster? I have to double check the maf reading. Swapping o2 now.

 

[TurboBob]

unplug the stock O2, reset the ECM, and see what happens.

the O2 you are replacing... is it the stock one or the wideband?

B

 

[LEGACY_GN]

Stock one. wideband is only a year old. Stock location one is a bosche I got 4 years ago and everyone tells me they are bad so I got a denso this time. Had to special order it. No one carries them. Only bosche. I'm really wondering if it might be a stuck injector the more I research it. They are about 7 years old.

 

[TurboDave]

Its not rich. It's lean. BLM is adding fuel when the number goes above 128. The wide band is further indicating, your lean. Sounds like something blew off or the maf crapped its pants.

115 BLM is pulling fuel out NOT adding.

 

[LEGACY_GN]

115 BLM is pulling fuel out NOT adding.

Right, it's pulling fuel because it's rich or am I misunderstanding? and btw, any throttle and it goes up to 128 range. Only idle is rich. Going down the road it seems to be fine.

 

[TurboBuRick]

Yes. Under 128 is pulling fuel above 128 is adding. I misunderstood the o.p. My bad..

 

[LEGACY_GN]

That did it. O2 sensor was bad. Runs perfect now. Amazing how much a difference that made. thankful I don't have to replace my injectors. Thanks everyone for your help. Really appreciate all the feedback.

 

[LEGACY_GN]

It came back but now is intermittant. Sometimes it drops to BL 115 and other times it's fine. I have no clue what it could be now. New IAC and O2 sensor.

 

[20psiofevil]

What does blm stand for?

 

[Heskahoka]

BLM stands for Block Learn Multiplier or Block Learn Mode depending upon who you talk to.

Per the Turbo Regal Web site page: "In a nutshell, the Block Learn Multiplier (BLM) is the long term fuel adjustment that the ECM "learns" to keep the air/fuel ratio within acceptable parameters. " http://www.gnttype.org/techarea/faq/BLMINT.html

There is additional info on Vortex Buicks. http://www.vortexbuicks-etc.com/Scantool_Readings.htm