Hello...new guy here,
My 350 TBI is running really lean recently. I hooked up WINALDL and is showing numbers in the 150-160 range for the BLM's. I got a code 44 the other day. At a cold start, it runs like crap, missing and hesitating, if under load. Once it goes into closed loop, it does the same thing, just not as bad. How can it all of the sudden start running lean like this? TPS is showing .5 volts at idle, MAP is at 35-36 kpa at idle in drive. I included the log text from WINAldl. Any opinions?

Thanks in Advance.

 

Thanks everyone for the reply.....

 

Did u check ur CTS Sensor? I am just guessing since no one else responded. If that is bad, it will mess up ur air/fuel ratio.

 

whats SENSOR:Knock counter because you read out 0 at first then go up to 66 increasing over time, i dont know i am comparing them to mine and mine stays at 0. and the coolent temp is 71 and mine is around 78 and thats about 185 deg so i guess thats ok. and SENSOR:IAC i dont know but i am pretty sure that the iac is supposto be at 0 all the time other then start up, when it is in open loop and it is used to raise the idle but in your data it is always open.

 

Just looking from line 233 on tells me you're getting detonation. Looking at the O2 volts tells me something doesn't make sence. You say it's running really lean and hesitating but if you look the O2 says rich. I'd try a new o2 sensor first. If doesn't look like a fuel delivery problem. Were you really going over 130mph in some parts of this data log? Cause your ecm says you were.
Does the car ever stall when put into gear when in open loop? Can you hear it backfire through the intake manifold ever?
Looks like the ecm thinks you're running lean when you aren't. There isn't really any other explination for the amount of detonation you're getting! 66 counts is a lot. Only way for you to really get that much detonation under running the car pretty hard is if you were running too rich and too much advance timing. It doesn't look anything like you're having fuel delivery problems or spark problems.
If you could, datalog a run where you don't move the pedal fast. Keep a steady SLOW foot and the ecm won't go into power enrichment mode. I don't know what ecm this is but from the looks of the data I'm guessing it's either a 7747 or the 88 TBI ecm whatever that model number is (like I give a rats ___).
Repost some more fluenty data and I'll take another look.