02 Sensor Plug Burnt Car Wont Start

[chrisdicko23]

I was changing the dump pipr on my 33 gtst( stock)

and forgot to strap in the o2 sensor plug and it melted through on the turbo

car now wont start, iv tried new plugs, no o2 sensor.

Any help would be good cheers

can the car start and idle with no o2 sensor?( no driving though dw)

[R31Nismoid]

O2 sensor has nothing to do with the car starting.

I've not run O2 sensors in 6 years.

[chrisdicko23]

:s

well i was driving along at 80k's and all of a sudden the revs dropped and i put my foot down a bit and the car died

and the o2 sensor plug was stuck on the turbo melting away

car was working perfectly before this

[Room42]

Just rewire it mate. Easy as. P.s I disconnected the O2 wire from my stock computer and my pfc and the car stalled both times. What does that tell you?

[mad082]

I was changing the dump pipr on my 33 gtst( stock)

and forgot to strap in the o2 sensor plug and it melted through on the turbo

car now wont start, iv tried new plugs, no o2 sensor.

Any help would be good cheers

can the car start and idle with no o2 sensor?( no driving though dw)

yes, yes it can. will just run a bit richer at light load (instead of the AFRs being around 15:1 it will be about 12:1). at heavier throttle % then it won't be any different as the ecu ignores it anyway

[chrisdicko23]

Just realised theres no fuel pump prime noise any more, sure enough undid the hoses and tried starting the car and no fuel was coming out, taken the fuel pump out and manualy it works.

Fuel pump fuse is fine to.

[JonnoHR31]

Just rewire it mate. Easy as. P.s I disconnected the O2 wire from my stock computer and my pfc and the car stalled both times. What does that tell you?

it tells me you disconnected something the ecu actually needs, like the cas. as nismoid said the o2 sensor is not needed for the car to run and drive. its a fuel saving device and it only used when cruising along at a constant throttle

[GTSBoy]

More than likely you have killed something in the ECU when the power supply to run the sensor's heater shorted against the dump.

Edited June 25, 2011 by GTSBoy

[chrisdicko23]

Already tried changing ecu's

[GTSBoy]

Get the wiring diagram and start looking for where the common power feeds are to see what you've shorted out. It is pretty clear that when the wiring melted on the exhaust that a big bad electrical failure happened. It doesn't take a rocket surgeon to work that out.

[Room42]

it tells me you disconnected something the ecu actually needs, like the cas. as nismoid said the o2 sensor is not needed for the car to run and drive. its a fuel saving device and it only used when cruising along at a constant throttle

Haha probably aye. Actually now that I think about it, it was the wrong wire. Dur... I remember that I unplugged the wrong wire and it didn't run and then realized and got the right wire (the clear one). My bad

[RRob]

Check all the fuses....

[paulr33]

yep check every fuse and relay to be sure

look in engine bay

look in boot

and next to steering wheel (check every fuse)

[chrisdicko23]

Ok guys il post up what i started in anotger section with all the info u need

[chrisdicko23]

Hey guys in a bit of a pickle!

Was driving the other day and car just cut out on me and wouldnt start. I then looked under the hood and saw that i melted my o2 senssor wires onto the turbo manifold and that appeared to be the problem until i disconected it and tried starting with no o2 seonsor and got nothing. Next i took off the fuel lines into the engine and turned ignition on and found no petrol pumping or any sort of prime noise! So i took the fuel pump out and stuck it directly into the engine and ran it manually and the car started and reved up. So i assumed i had stuffed one of my relays to the fuel pump. To my understanding it is either both or one of the one behind the ecu in pass kick panel and in boot to the right of fuel pump fuse. They appeared to work fine after testing. Next i tried looking at the pump control unit and found no burns on the board but am not sure if there would be from 12 v? So not sure if thats working or not. Also i ear there is a ballist resistor connectin to the fuel pump in the boot which i have not yet looked at but am not sure what its duty is and if it can actually short circuit?

Need help!

Oh and also tried a mates ecu and nothing. So inconclusion there is no power on the wires on top of the fuel lid

[JonnoHR31]

trace the wires back until you find power

[chrisdicko23]

Problem solved. did a few things and somehow its working! Cheers for the help guys!

[Simon-S14]

had this exact same thing happen before... O2 sensor wirings have 12V power and signal wires/ground going to ecu... if you short them together it WILL fry the ecu.

lucky for me i fried an injector driver for cyln 5 on the circuit board so it still ran on 5 cylns... i was able to un solder the fried driver and replace it.

[chrisdicko23]

Sounds like it depends what sort of shorting happens as to whether it frys the whole board or just a certain thing. It could also be in safe mode. But i noticed power to the fuel pump after i put a direct negative to the relay in the boot at the pump started to prime.. I then took it off and it still primed for another second or so and since that direct negative its been working without my direct negative but using the ecu to turn it on again! No idea why?

[Dose Pipe Sutututu]

The ECU has a -ve trigger for the fuel pump. On shorting the O2 you must have fried a common point somewhere.

Try using a multimeter and testing the fuel pump trigger on the ecu (-ve output), it will stay on for a few seconds if the motor doesn't kick over.

Work from there!