Hi i have 1999 toyota corolla 172 thousand miles. Sometime when driving check engine light flashes. Put the best spark plug and wires on it oil change . Took for a diagnostic test says missing on all 4 cylinders catylatic convertor and combustion. So i replaced catalytic convertor. Still runs rough. Then pulled spark plugs one plug is black. Plug number 4 to be exact. All fuel injectors good. Any idea what yhis could be.
Wet black or dry black?
How did you determine that all fuel injectors are good?
Are there new codes?
Exactly what were the old codes?
A misfire code usually means the gas and air inside the cylinder is not exploding for some reason. It’s got to be something simple, since it is easy to make gasoline explode.
- Too much or too little gas – fuel injector, fuel pump, fuel pressure regulator
- Too much or too little air – air filter, cat plugged, air leak into engine
- Lack of compression – easy enough for a shop to test
- Lack of robust spark-- spark plug, ignition module, battery,. coils, hv wires
- Spark ok, but at wrong time – cam sensor or crank sensor
It sounds like you used aftermarket wires and spark plugs. When it comes to Toyotas I would stick with OEM wires and plugs (NGK or Denso). If it has a distributor I would check the cap and rotor and replace (OEM as well).
All codes p0303 p0300 p0301 p0302 p0303 p0420 p0505 p1300 p0304 p0420 ive changed injectors wires plugs and catalytic convertor please help me. Oil in 4th cylinder
And cylinder number 3 misfiring at wrong time.
Have you performed a compression test?
Have you hooked up a noid lite, to verify that the injectors are indeed being pulsed correctly?
So what kind of plugs did you use? . . . I would stick with the exact parts listed in the owner’s manual
No compression test and i am putting ngk ones in now
Is there a chance the plug wires have been switched around accidentally? Going to the wrong plugs? Years ago my dad had a bad misfire problem with his truck, and it turned out some neighborhood kids had switched the plug wires around as a prank. On some vehicles it is phyically impossible now to mix them up, but if it is possible on your car, double check that the plug wires are hooked up to the correct cylinders.
Im going nuts all 4 cylinders missfiring code p0505 code p1300 p0420. Car runs bad at stop signs in drive konks out in reverse now backfires sometimes. Also has oil in #4 sparkplug getting valve stem seals done tommorrow. Hopefully this solves my problems as is also burning oil. Tailpipe is black. Blows blue smoke at startup tjen no smoke at all.
p0505 is a problem with the idle speed control valve. p1300 is an ignition system malfunction. p0420 is a cat problem code. I’d focus on p1300 first, as it might be the cause of the other problems.
The ignition system is a set of electronics, most of which is part of the engine computer ass’y, that has the job of firing each spark plug, one at a time, at the correct phase of the corresponding engine cycle for that cylinder. The way it works, it first figures out what cylinder is next up to fire, whether it is in the exhaust or compression phase (via the camshaft position) then what phase the piston is at (via the crankshaft position), then when it is at the correct number of degrees before the top of the compression stroke, it goes ahead & sends an electronic pulse to the igniter which fires the spark plug. Bam. So there’s a little dance involving the crankshaft, the camshaft, and the computer going all the time the engine is running. It appears your engine’s dance has hit a little niggle. There’s just no “do si do” in your square dance. Maybe there’s a “do” but no si. Or maybe there’s a “si” but no “do”. Well you get the idea. All that has to work perfectly otherwise you’ll get misfires, poor idling, and cat codes.
Your engine is the 1zz-fe right? That engine has both a crankshaft and camshaft position sensor it appears. If either of those failed, it would foul up the ignition system to a degree it just wouldn’t know what to do. Your engine’s square dance would turn into a freak out. A visual inspection might show a wire has come loose, or a corresponding ground isn’t making a good contact. You haven’t had any work done involving the crankshaft, flywheel, camshafts, right? Those contain the part the corresponding sensor senses.
If the position sensors are ok, then you’re looking at a problem with the ignition module, which probably contains the coil too. There’s tests a shop can do for all of these ignition problems. Best if you can choose a shop which has the Toyota scan tool.
Valve stem seal problems usually wouldn’t cause backfires. And they usually wouldn’t cause the array of symptoms you describe. Those sound more like igntiiion system problems to me. You may well have problematic valve stems, but I don’t think that’s the entire problem here.
So coil packs and ecm is what i need