tchampton

Ok guys I need help I got an 89 formula with the lo3 mild stuff done to it ran good a year after rebuild now I got code 42,44 Esc and lean exhaust car likes to cut out pop out the exhaust on high way and out tbi in town that tells me timing iv checked it 10times its set right on base so my blm is 128 idk if that's good or bad it just stays there my O2 reads .45,.00,55v it changes in that range I'm thinking the dizzy is bad its a year old and I'm gonna warranty it but want ur thoughts and idle map reads 20hg driving its 7,10hg seems normal to me the car has a lt1 cam and tbi spacer again idk if that matters still on factory tune

RFmaster

Check your fuel pressure - fuel pump might be going out on you. BLM should stuck at 128 would indicate car running in OL. O2 voltage should vary between 0.2 to 0.8 V. If it is stuck around 0.450Volts that would indicate dead or disconnected O2 sensor.

//RF

tchampton

its a new fuel pump but ill look at it but the o2 switches .00,.45.55 it switches but it likes to stay at .00v idk how gm os2 are suppose to work but according to the scan tool im using its running lean in closed loop it runs good tell warmed up but if I can get an obd 1 cable made ill data log and post but I cant promise since im still learning how to use it but the car is at the point once warm it don't even wanna idle the tach needs jumps all over the place.

RFmaster

0.45 to 0.55 volts is not a switching voltage how GM has intended. In a close loop (CL) operation ECM varies fuel delivery so that the O2 voltage oscillates between rich and lean states. Rich => 0.8 volts, Lean <=0.2 volts. When O2 voltage only wobbles between 0.4 to 0.5 you should check or replace O2 sensor. If o2 voltage in scanner reads 0 volts than check for short in a purple wire.

//RF

89-S-dime

iTrader: (3)

prior to your car throwing 42,44 codes and lean exhaust, your saying it ran good with LT1 cam and factory tune?

tchampton

yes ran good for a year no probs it was daily drive and taken across the state many times for school ik the computer had to be going crazy on the factory tune I just don't feel like I can tune it yet and don't have money for another year to spend the 350$ to get it tuned since im a full time college student but yes it ran good had more power after the rebuild but I got a decent list of mods I can list them all if it helps anyone but I think its the dizzy since I keep getting code 42 I think that is the esc the dizzy is still under warrenty so in the next few weeks im gonna try to come up with the money to ship it out for a replacement