Will a bad O2 Sensor cause a 92 Toyota not to start?

Question

How can I test it? Or bypass it to try and get the vehicle started?

I have checked everything in the book...

- Checked fuel filter and replaced, was pretty clogged

- Gas was get pumped from fuel pump (in tank) to the inline filter during turnover - not sure about fuel pressure?

- Checked gas line at the engine before injectors, was getting gas during turnover

- Stuck test light to injector plug and lit up during turnover

- Pulled plug, grounded to engine and got a spark

- Plug also damp with fuel, so tells me there is fuel passing through the injectors - so assumed fuel pressure is good??

- Air filter is good, just replaced not long ago.

- Opened radiator and turned over to check for blown head gasket. No back pressure from engine. Also drained oil to make sure no coolant.

- Spark Plugs not that old. But changed anyway due to high mileage and some oil usage

- Replaced distributor cap / rotor not long ago... replaced again and nothing

- Fuel Pump not coming on when I turn on the key. But works when I jump it using the di

Answer 1

that shouldn't cause it not to start, check the normal things :)

Answer 2

The O2 sensor on you Toyota is for Emissions purposes and to adjust the Fuel - Air Ratio. If it senses the car is running lean it will add fuel and visa versa. If the O2 sensor fails the car will run poorly and less Efficient and most likely not pass Emissions inspection. However would still run and start just fine. The first place I would check on your vehicle is the Timing Belt as they tend to break and the car will crank but not start. Check this with a compression Gage in place of one of the spark plugs in one of the cylinders (these are available at your local parts store for around $50 US). If the belt is broken you will have NO compression, you should have a reading of over 150 PSI. If you compression is good Your probably looking at a Fuel or Ignition problem. Diagnosing that requires some tools such as a fuel pressure tester and spark tester to see if the spark plugs are firring.

Answer 3

understand first what the O2 sensors do. quantity one is the significant one. the laptop reads how plenty oxygen is interior the exhaust at that factor. quantity 2 reads for oxygen after the cat to work out no be counted if that's doing it is activity. Now understand that the laptop makes use of those readings to alter the gas mixture going into the cylinders. there is an inherent postpone in this technique so the laptop is often making corrections, in spite of everything you're shifting the gas pedal all around are not you? So now for the code. You stated it is the heating circuit. So i could look for the flexibility furnish to the O2 to repair that no longer substitute the O2. Forgot, the exhaust leak shouldn't result the O2 sensor until there is not any exhaust going previous it. you may get a code if that replaced into the case. So now on on your situation. look for a vacuum leak around the intake manifold. sparkling the throttle physique and air by using bypass. verify the EGR valve to work out no be counted if that's clogged up with carbon or sticking. Coil packs, look for a omit. Up bypass no longer down bypass.

Answer 4

When you used the test light on the injectors, did it flash, or just stay on?
When you are cranking, are you pressing the throttle all the way to the floor? if you are, the computer interprets this as a "clear flood' command, and will turn off the injectors until it sees < 75% throttle angle.
When it turns over, does it sound "different"? If so, you MAY have lost the timing belt.
Use your manual for a discussion relating to checking of the belt and cam / crank position.

Good Luck and Merry Christmas

Answer 5

not likley faulty o2 sensor will set check engine light and cause rich condition as a default. check fuel psi on fuel rail ( intake manifold) looks like a tire valve. not sure of your toyota but most fuel injection needs at least 30 psi test gauges are cheap. if no psi check for pump operation if none check pump electrical circut
fuse, relay or connection. or could be a crankshaft position sensor but I doubt it.

spray starting fluid in intake if engine sputters you know its not getting proper fuel do this first

Answer 6

No, even disconnected, it will run. You best get it scanned to find out what is wrong. The three things to look for are Fuel, Spark and Compression. If any one is missing, you have a no-start and a direction to look at.

Answer 7

No, the O2 sensors don't come into play until the engine is warmed up. The O2 sensor won't prevent the car from starting.

Answer 8

no it wouldn't.....but if you want to bypass it just get a small resistor like a 1K or 3.3K and insert where you would normally connect your O2 sensor....not the best thing to do, but wont cause major damage!

Answer 9

No, it has nothing to do with helping your car start, or to keep it running. It is something else wrong with your car.

Answer 10

NO this will not cause a no start. Keep Guessing.