Car Will Not Start And OBD Code p0420
I just put a scanner on and got a code p0420 ,my problem is the car won't start it cranks but no start ,day before yesterday it started no prob today no go this has happened a few times ,help please
Diagnostic Trouble Codes (DTC) P0420 and P0421 indicate that bank 1 catalyst system efficiency is below the acceptable threshold.
Most of the time this code requires cat converter replacement to fix the converter is no longer efficient. This would be the passenger side. This will not cause a no start check for spark and fuel I would suspect a fuel pump or fuel pump relay is causing this no start. Make sure you have crank signal from the crank position sensor and check the fuel inertia shut off switch.
I would check for fuel pressure when it happens. I would lean more towards a fuel pump or fuel pump relay swap the relay with a headlight or AC relay I believe they are the same compare the part number on them.
Make sure the crank sensor reads cranking rpm about 100-150 rpm when cranking also check the wire to the crank sensor they chafe on the AC compressor.
Car wont start when cold
2000 grand marque 130000 miles 302 motor i believe had plugs replaced at dealer they said no bad codes in computer good gas pressure only hard starts when cold when engine warm runs fine.
Your 2000 Grand Marquis has a 4.6L V8. But that's OK.
It sounds like you have a fuel pump problem on cold start.
One way to verify that this is the problem, in the morning when the engine is cold, turn the key to on, NOT START, just on. Leave it there for 3 seconds then turn it to off and then repeat this process 3 times.
Then try to start the vehicle.
If it starts right up, the problem is the fuel pump.
What is happening, overnight or when the vehicle sits for a period of time to cool down, the fuel is returning to the fuel tank. The fuel pump has a check valve in the pump that keeps the fuel in the fuel lines to the engine for easy starting.
When the check valve goes bad, all the fuel in the fuel lines drains back to the fuel tank. Then you have to crank, or cycle the key in the ignition to resupply the fuel lines to the engine.
The check valve is part of the fuel pump itself and is only available with the complete fuel pump assembly.
You will get no codes and the fuel pressure will still be good with the engine running.
You will have to cycle the key on to off.
The fuel pump will only come on for 3 or4 seconds and then turn off. That is why you will have to cycle the key.
If your Grand Marquis has rear air ride suspension, the noise may be the air pump for the rear air springs.
The fuel smell is from pumping the pedal. On fuel injected vehicles, you do not have to step on the gas pedal to start the vehicle, only on carburettor engines from years ago.
To repair the problem, the fuel pump in the fuel tank will have to be replaced. But if you can live with cycling the key on cold starts, you can put it off till later. It will not cause any other issues or problems.
Only the fuel pump itself will cause this, the check valve is part of the pump.
Like I stated, if you can live with cycling the key 3 times when the engine is cold, then you can wait till later to replace the pump.
Security Light ON and Car wont start'
Chevrolet Blazer 4.3 V6 2001 R/H drive.Security light is ON and car will not start.Please help.
This is a common problem with the Passlock security system...turn on the ignition key and try to crank the engine..than let go of the key and wait for 10 minutes, until the security lamp goes off...when it does, try to crank the engine again...if it doesn't fire up then try the 30 minute reprogram procedure.
Another possibility can be shorted fuse or low battery:
I think you may have a shorted battery...the dome lamps and the door locks are another indication of this. Also, these battery positive cables are known for coming slightly loose and driving the on board computers crazy. Check the cables for tightness, if they're loose you'll need to recharge the battery..if they are tight, you'll need to take the battery out and have it tested...it may very well be defective. If the battery is good and cables are tight, be sure there is no corrosion on the cables or where the negative cable attaches the the engine.
Try the 30 minute relearn, otherwise it may have a Passlock Sensor failure or other anti-theft component failure...which will need to be scanned with a dealer level scan tool. There is no way to bypass this style of alarm system, and the keys are not programmable either...try the procedure below a couple of times..
30 Minute Learn Procedure
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds .
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlock(TM) Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK). IMPORTANT: The vehicle learns the Passlock(TM) Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine (the vehicle has now learned the Passlock(TM) Sensor Data Code and/or password).
With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).