Running lean

[a91talonawd]

I just installed my 750cc injectors and the GM MAF and MAFT. I am having problems tunning for the injector compensation. The issue is after it is warmed up and drive a little bit I start going very lean to the point the o2 voltage is pegged at 0volts. the o2 trim is maxed and then it goes open loop and stays there! It seems that it doesn't matter what I set the aux and base settings to at this point I stay LEAN at idle. adjusting the injector size via the aux and base knobs seems to not have an effect.

[TurboBob]

which MAF, is it set up blow-thru or draw thru, what chip are you running?

What are you using to datalog with?

Bob

[a91talonawd]

3 inch GM MAF, blow through, data logger (palm) mmcd. stock ecu no chip

[admin]

Where did you get the MAF sensor?
Mike

[a91talonawd]

Originally Posted by admin

Where did you get the MAF sensor?
Mike

I bought it used from ebay

Do i need to have the ecu chipped to run this set up?

[TurboBob]

normally no,

are you getting any cel codes?

what are your current settings?

Bob

[a91talonawd]

Originally Posted by TurboBob

normally no,

are you getting any cel codes?

what are your current settings?

Bob

no check engine lights no knock counts

The settings I start out with are aux-2 base-2 idle-4 mid-3 wot-0

they seem to work till warmed up and goes to closed loop then everything goes south till o2 volts get pegged to zero and o2trim is maxed

[TurboBob]

when running open loop while warming up, what is the O2 reading?

What are the trims?

Bob

[a91talonawd]

Originally Posted by TurboBob

when running open loop while warming up, what is the O2 reading?

What are the trims?

Bob

well after reseting the ecu before start up and as it warms up the o2 reading is approx .8 volts and the fuel trims are all 100%. o2 trim is like 100-120%.

[TurboBob]

It sounds like the O2 sensor is working ok.

I wonder if its ignoring the MAF during warmup, once it switches to closed loop, does it start running badly immediately?

Bob