1997 Camry 230K Auto all stock. 5SFE
No recent work done to car. Plugs and wire are about a year old and have aprox 15K on them.


The other day the GF was taking the car to a Dr. appointment and at a light in front of Dr. the CEL come in and car looses power and starts to vibrate. She pulls into Dr and shuts it down, calls me. I arrive and start it and it obviously had a miss so I pulled spark plug wires to find the #3 cyc is dead. I pulled the plug and it looked normal, like the rest. Tested for spark and there was spark. Figured the worst so I towed it home.

At home I did a compression test and #1 210 #2 220 #3 220 #4 220 So I don't think its a mechanical problem. Than I figured it was a fuel issue. So pulled the fuel injectors and swapped #3 with #4 and put it all back together started it up and cyc 3 still dead (when you pull wire when running no change). While running this time it suddenly got worse...I pulled #3 wire and stayed the same then I pulled #2 wire and it also stayed the same...now I have two dead cyc??? When I pulled #1 or #4 it ran so band it stalled! WTF? So what connects #3 and #2 cyc Ahh the coil pack. So I went out and bought a $80 coil pack and installed it....no change same problem.

P0300 P0302 P0303

So I'm stumped. We know it had visible spark, how hot I do not know. I know it sometimes does not fire on cyc #2 and always does not fire on cyc #3. Swapping fuel injectors make no change. What could be causing this?

Ideas....

 

Suggest the first action is have any codes read. Your GF experienced a direct correlation between the check light and symptoms of a problem (loss of power) which is not that common. My guess is it is coil, the code(s) may identify which one.

The injectors and fuel system are not monitored by the computer but if a fuel problem there maybe a code that the engine is running too lean or rich.

 

Did you read it?

Coil has been replaced.


"The injectors and fuel system are not monitored by the computer" Neither is the ignition system, faults that throw "P0XX" codes are tripped by the crank sensor not seeing the rotation at 90* intervals.

 

A suggestion was made that it could be a vacuum leak. That had been checked. Was not the issue.

 

There is a laundry list of items that can cause these codes.

Injectors
Ign system
EGR
Compression
Fuel pressure
Valve clearance/timing
MAP sensor
Wiring
ECU
ECT sensor

P0302 and P0303 is a misfire of these cylinders. P0300 means random misfire of these cylinders rather then the misfire at these cylinders occurred and was recorded at different times

Swap the working cyl 1 and 4 coil with the other and determine if cyl 2 and 3 now operate any better or the others worse.

Check spark at all plugs, compare 2 and 3 spark intensity with 1 and 4.

Check the plug electrode color and condition, compare 2 and 3 to 1 and 4 for signs of excess or lack of fuel. No spark can result in a wet plug, no fuel a dry plug.

With plugs out crank engine then compare fuel going into each cylinder looking for non-working injector

Check injector resistance. 13.4-14.2 ohm at room temp. Compare readings other injectors. Place your finger on each injector, engine running and feel for operation.

Note: The engine may or may not mix different injectors between cylinders. Look at the color of the injector body.

Take ohm readings of the coil between high voltage sockets, should be 9.7-16.7K ohms cold, 12.4-19.6K ohms hot. Compare readings of all coils with each other.

Make sure the replaced coil is getting 12V DC on the positive terminal.

Crankshaft sensor 985-1600 ohm cold, 1265-1890 hot.
Cam sensor 835-1400 ohm cold, 1060-1645 hot.

Make sure the EGR valve is off or not leaking at idle

Compression should be 178 PSI or greater, engine warm, throttle open. Max difference between cylinders 14 PSI

Eliminate the coil and plug wires as a problem by swapping, ohm measurement, etc.

Compare operation of injectors and ohm readings.

Injectors due fail but coils fail much more often. Either not work or leak.

These are 12V DC powered, the brown wire is the power wire. The computer grounds the other wire for operation. You can test the injector off the engine if you can plumb it to cars fuel system or air might work. Typical fuel pressure is around 44-50 PSI.

 

Excellent info man thank you. Being I'm not familiar with this motor what are the more common issues so I can check them first.

-According to Autozone the coils are different and cant be swapped, true? Regardless I replaced it already with a new one, did not help.

-All spark plugs look great, normal wear but all evenly worn. I was a sudden issue and only ran a few minutes since this all started so not much time to foul plugs.

-Will check injector resistance today. They "feel" like that are working and I did swap #3 and #4 and problem stayed on #3 All injectors match colors.

-Will Ohm out coils today

-Will Check crank and cam sensors today but could either cause only one cyc not to fire?

-I will check EGR, also can this cause only one cyc not to fire?

-Compression is 220psi across all four cyc.

-ignition wires test good.

-I'n borrowing a "noid" light today to further check injectors.

Thanks again for the info and I'll keep you posted.

-Mike


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Your posts stated cylinders 2 and 3 are not working as the plug wire can be removed and the engine performance does not change. Coil failure would be the first place look.

Make sure the new coil can actually fire a spark plug.

The other issues such as EGR, sensors, etc are more generic for misfire code.

Check injector ohms, another problem but less common then coil.