tonight i replaced everything in the hei distribitor, and it still backfires out the tbi. only codes im getin here now are 42 44 45 im running broke and need this blazer for work please help!!!!

 

42 – Bypass or Electronic Spark Timing circuit - The EST signal did not change when the ECM applied bypass voltage to the ignition module.

44 - Oxygen sensor or circuit – lean exhaust detected. - Oxygen sensor voltage was under 0.25 volts for up to 4 1/2 minutes of closed loop operation.

45 - Oxygen sensor or circuit - rich exhaust detected. - Oxygen sensor voltage was over 0.750 volts for 2 minutes in closed loop operation with a throttle angle between 0.6 and 1.9 volts.

I dont think your oxygen sensors would cause that backfire

 

im not sure what to do with it, it has got worse in the last couple weeks, doesnt mater what i change on it, im strartin to lean toward faulty ecm! but not sure couse it never stalls out

 

Lets start with what you have already done...

How does it run with the O2 sensor disconnected?

 

sorry my pc died! runs the same on or off! we tryed that saturday night. i was readin that a fpr can drip fuel into the intake cousing a backfire im not ruleing anything out, but it does just seems to be more electical than simple macanical if im running highway speed it does pritty good till i have to put it on a load! thats when it starts to pop, but its not missing under a load at a stoped point!

 

it allso stinks out the tail pipe (very raw) and smells very gassy under hood right after shut down. i know also before it started popping on me the check light would comeon and id loose power like it was flooding, shut down and restart would cause a thick blue smoke for bout 2-3 sec. i was geting code 42 and 44 then,but now its the outher way around, it runs better with the light on less popping and now adding 45 to the sequnce!

 

Try unplugging the map sensor and see if it stalls or not

 

yes it stalls, we seam to have got rid of the poping, it was advanced too far my dad said , but still kicks the light and runs like its flooding with NO power till i restart at a roll!