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

[LEGACY_GN]

I always thought it was block learn mode. Learn something new everyday. Thanks for the info

 

[LEGACY_GN]

Any other ideas? No vacuum leaks, new IAC didn't fix, new o2 made it intermittent. Only does it at idle.

 

[whitehot1]

Do you have another ECM you can try?

 

[LEGACY_GN]

I was starting to wonder that too but it started after a backfire, so I thought maybe not. Going to try one this weekend.

 

[Pronto]

I had a pop once and it messed up the MAF. What is the MAF reading when it runs better vs when it runs rich?

 

[TurboDave]

Any other ideas? No vacuum leaks, new IAC didn't fix, new o2 made it intermittent. Only does it at idle.

Yes, you never clarified what the MAF reading was at idle when it's acting up. You mentioned some numbers earlier in the thread of something in the 40-50 range which are impossible numbers at idle!!!!!! The MAF should be 5-6 at idle if working properly.
If the maf isn't reading somewhere between 4-6 at idle, throw it away.

 

[LEGACY_GN]

Yes, you never clarified what the MAF reading was at idle when it's acting up. You mentioned some numbers earlier in the thread of something in the 40-50 range which are impossible numbers at idle!!!!!! The MAF should be 5-6 at idle if working properly.
If the maf isn't reading somewhere between 4-6 at idle, throw it away.

I'm sorry, that was map reading. which one is maf reading?

 

[Nascar83Fan]

You may of been looking at the LV8 numbers on the scanmaster instead.
To answer your question on which one is the MAF reading:
AF is the MAF reading on the scanmaster.


Posted from the TurboBuick.Com mobile app

 

[LEGACY_GN]

Ok, what does it need to be at idle and what should it go up to with light throttle?

 

[Pronto]

From Vortex Buicks:
At normal idle, the maf will read 4-7 on the scan tool (again, this is with more conventional chips-Bob's Extenders may read less).

At wide open throttle, the reading will depend upon air flow. Typically stock engines around 15# of boost would show something like 240-245 on the scan tool maf parameter. As I recall, very few hit 255 until the boost was around 17#, or a bit higher.

 

[LEGACY_GN]

Maf is reading 7-9. at idle. Fuel pressure hose off is 44, hose on is 41. It's definitely running out of gas when the bl drops to 115. If I don't give it throttle it will die and the wideband is reading 18.0 Driving the car runs great and very strong, with 128 to 132 BL. just won't idle for shit. I think the computer is mistakenly reading rich and cutting fuel causing the car to die. I don't know. Pulling plugs tomorrow. Injectors clogged or bad maybe? Or bad ECM?

 

[TurboBob]

unplug the stock O2, reset the ECM, and drive it around.

Bob

 

[Chuck Leeper]

It's definitely running out of gas when the bl drops to 115.

??

 

[TurboDave]

It's definitely running out of gas when the bl drops to 115. ?

I'm sorry, but that statement doesn't make any sense.

 

[TurboBob]

I think he means that its going lean. which makes sense if the stock O2 is lying and the wideband is accurate.

B

 

[LEGACY_GN]

FOUND IT. Won't believe this. Ok, so replaced o2, IAC, plugs and ECM and no change. Still acting up intermittently. Drove to breakfast this morning and noticed my old air fuel gauge on a pillar wasn't working and I never noticed because I use the scan master now with the wideband. Well, instantly I knew what happened. The power wire from the gauge was pinched by the emergency brake pedal (i've had this issue before with dash lights shorting out) and was grounding out not only the gauge but the narrow band 02 sensor it is tied into causing the ecm to mistakenly think it was rich, which caused it to cut fuel even though the wideband was reading lean. See I was getting a 115 BL which means rich and a 18.0 wideband which means lean. Runs absolutely perfect now. And it did start right after I used the e brake. Anyway, I can't thank all of you enough for all your help and suggestions. Means a lot to me. So if anyone ever gets a low BL and lean wideband, your 02 is shorting out somewhere.

 

[Pronto]

Well, that was unexpected. Glad you founderstand the issue and all is good.