hey question, will the ecm function with out an o2 sensor?

 

simple answer - no. the o2 sensor is the main senor used to dertimine air/fuel mixture for your engine. based off of o2 reading the ecm adjusts fuel, air, idle speed, rpm, and many other things. your o2 sensor is extremely important. why do you ask? do you have a code or a o2 problem?

 

i ask because i switched to a set of flowtech headers and it hasnt been sent to my buddy to get an 02 sensor bung welded in yet. y i ask is becasue i rebuilt the cylinder heads put a new distributor, alternator, egr valve into it . basically rebuilt the top end even the tbi has been rebuilt. now that everything has been reassbled the injectors do not want to fire i have 11 psi at the tbi in the regulator fuel pump is a brand new strainer assmbley pump sender etc, there is no voltage heading to the injectors from the ecm. the only thing that hasnt been replaced is the sensors the tps passes the test, the distributor is installed correctly ( tdc combustion #1 cylinder point at #1 cylinder) ive even gone to do continutiy checks on all the wires, and all passed fine and now im kinda stuck wondering where to go to next, a friend of mine suggested a crank position sensor but to my knowledge this truck doesnt have one its built into the distributor. Just looking for the next step in trouble shooting as im use to carbbed engines not fuel injection

 

I was also told the with out the o2 sensor the motor will still run but according to the wiring diagram its also a ground for the ecm

 

your truck should have a crank sensor and their should also be a cam sensor thats in the distrubitor. both of those sensors tell the ECM when to fire the injectors so i would check those out.

 

yep figured it out the esc modual in the distributor was off got fuel and spark no but she is burping fire lol im figuring the dizzy is timed to tdc compresion and the valves are timed to tdc exhaust so now i gotta start at the begining for the timing do you know a good place to start im going to losen my rockers but with them losened how is it possible to distingus bettween compustion and exhaust tdc haynes manual just states tdc h. b. mark tdc

 

both valves will be closed on the compression stroke.

 

yep figured as much cant wait to get everything perfect tomorrow well ive learned alot about the tbi set up rebuilding the top end of this motor