Hi All.

I have searched the forum for ppl with my issue but no luck. The explanation below is a bit long winded I tried to encompass all I have done. Thanks in advance for reading and helping.

I am at my wits end. My wife's 99 Camry with 1MZ-FE 3.0L engine started running with very limited power while I was driving. This happened out of the blue traveling around 45mph. Under load I could barely accelerate. Under idle it has a deep vibration it never had. I was running low on gas at the time(nothing too extreme but I had a 45 min drive home). Only put 1/4 tank in thinking it may be fuel issue and don't want to drop a tank full of gas if I have to change the pump (not sure if that is necessary or not). No change.

Got the codes read as soon as it happened....P0303-Cylinder 3 Misfie, P0441-Evaporative Emission Control System Incorrect Purge Flow, and P0446-Evaporative Emission Control System Vent Control Malfunction.

The P0446 code has been on for a while (like a year or so). I switched a $50 solenoid by the charcoal canister in hopes it would fix the P0446 but no luck. So this is an old issue. (I don't believe it is related to my engine issue but any ideas welcomed!)

The other 2 codes are new. I changed the plugs and wires (perhaps a little hastily without knowing the true issue) and that didn't fix it. I swapped coils and didnt fix. I borrowed a code reader today and read the codes again and (after clearing the old ones first by disconnecting the battery) received P0300, P0301, and P0303.

FSM says possible causes are....

• Ignition system
•  Injector
•  Fuel line pressure
• EGR
•  Compression pressure
• Valve clearance not to specification
• Valve timing
•  Mass air flow meter
•  Engine coolant temp. sensor
•  Open or short engine wire
•  Connector connection
• ECM

Changed fuel filter. No Change.

Checked for vacuum leaks. Nothing. Although a vacuum leak would most likely cause a lean condition, of which I am not getting.

MAF is good.

Need to check fuel pressure. Is there a fuel pressure service port anywhere to check fuel pressure or do I have to make T-fitting?

Any way to check EGR function without hand held pressure thingy?

What the heck does Engine Coolant Temp sensor have anything to do with these codes?!

Checked to ensure valves were in time and they are. Cam shaft may have jumped a tooth but I would think compression numbers would be a lot lower.

Compression check numbers: psi
REAR
Cyl 1 - 190..........Cyl 3 - 193..........Cyl 5 - 195
Cyl 2 - 200..........Cyl 4 - 205..........Cyl 6 - 210
FRONT
Service manual says anything 178 or more with nothing less than 142 is OK. Also says cylinders should have no more than a 14psi differential. These numbers seemed good to me but checked valve timing anyways. Timing is correct!

The, newly replaced, spark plugs in 1 and 3 had a lot of black soot on them comparable to the rest.

Also the exhaust has a sporadic 'PUTT' when it is running which is not normal condition. Like...putt putt putt....PUTT...putt putt putt....PUTT PUTT....putt putt putt…….....

I think that is all that I have done so far. Any ideas are appreciated. I am out of them.

-Josh

 

The P0441 and P0446 codes typically do not cause a change in engine performance and if it did would affect total engine performance, not a few cylinders.

Check the EVAP system for cracked, disconnected or broken hoses, the charcoal canister for cracks and the pressure sensor. Most EVAP components are up under the chassis, forward of the gas tank. You will need to get under the car to see them.

You changed the VSV valve, make sure the electrical wiring is OK.

The P0300 is a general code.
P0301 and P0303 refer to specific cylinders having the miss, 1 and 3.

Each coil fires two cylinders (1-4, 5-2, 3-6).

Suggest swapping one of the coils from a cylinder linked to a code (1 and 3) for the coil that is not linked to any codes (5) and determine if the code now shifts to this cylinder indicating a bad coil.

If black soot only on 1 and 3 the problem seems localized eliminating whole engine issues on your list of potential problems. Suspect these cylinder plugs are not firing properly due to ign problems.

This engine model has had ign coil problems. AISAN brand coils (if so equipped), one of two brands used as original factory parts seem to have problems with age.

Suggest you start with the ign coils, make sure the wiring to them is OK, etc.

Ignition system - Check this

Injector - Happens but rare on two cylinders

Fuel line pressure - Would affect whole engine

EGR - Ditto

Compression pressure - Seems OK

Valve clearance not to specification - Rare if ever

Valve timing - Ditto

Mass air flow meter - Would affect whole engine

Engine coolant temp. sensor - Ditto

Open or short engine wire - If connected to coils. If connected to injectors they should turn off and the plug show lean.

Connector connection -Ditto

ECM -Has happened but there is typically a slew of codes such as from P0300 to P0306 and these would be false codes as in the spark plug condition would be OK.

 

Already did some coil swapping. Even bought a new one to try. This did not fix the issue

 

To review your original post.

The issue started when the tank was low on fuel or perhaps a coincidence.

The engine was never over heated?

EGR system is supposed to be off when engine is at idle. The EGR valve operation is powered by engine intake vacuum. If you can find the EGR valve, you can manually turn it off (assuming on at idle) by unplugging the small vacuum hose connected to the diaphragm can on the valve. Remove hose and plug it. The valve should now be closed assuming there was a problem with the EGR system keeping it open.

The coolant temp sensor sends a signal to the computer as to coolant temp. Based on this the computer sets high/low idle, fuel mixture, etc for a hot or cold engine.

Coolant sensor is located on coolant return water piping to radiator, has two wires. Ohm reading of sensor should be approx 0.5 ohm at 68F and approx 0.3 ohm when engine warmed up.

Running out fuel can cause a few codes relating to fuel trim.

Only plugs on cylinders 1 and 3 show signs of over rich, not 5 or any other cylinders?

Are the replacement plugs on 1 and 3 now showing the same soot issue and No 5 still normal?

Have you removed a coil from 1 or 3, installed a plug, and cranked engine to check for actual spark?

If all other plugs look OK but 1 and 3 AND ign OK then might be injector problem.

Check injector ohm reading, should be 13.4-14.2 ohm.

Make sure injectors are not sticking or stuck open. If the electrical plug to injector is removed, injector should be off when engine cranking. Otherwise if plug connected will still be spraying fuel when cranking.

If you have real time code reader with data output can access cylinder bank 1 and 2 data from O2/AF sensors B1, S1 and B2, S1 and compare Bank 1 sensor to Bank 2 and if Bank 1 running rich. This would confirm the issue of what seems an over rich condition in cylinders 1 and 3 as shown by the soot covered plugs.

 

Yes perhaps a coincidence.

Engine never overheated.

How will I know if the EGR valve is open or closed when i disconnect the hose? So if EGR sticks open then possibly a bad or dirty EGR?

I will check coolant temp sensor.

The vehicle never ran out of fuel.

Yes only plug 1 and 3.

Actually when I replaced plugs the originals looked fine (or at least same as the other 4). I drove an extra 30-45 min (city driving) after the code was thrown and the issue arose just in order to get home. I changed the plugs. The new plugs are the ones which are dirty. And I have not even driven the car since. Only time the car runs is to check codes or a warmup session for a compression test.

I did check for a spark but I think I need to check again. I will check tonight and get back with you.

I will check injectors after checking spark. Seems unlikely to have two injectors go at once though, right?

How would I check for injector spray when cranking?

I have a code reader but doesn't show that stuff. Thanks though.

-Josh

 

Ok so I touched the injectors with a screwdriver to feel the pulses. The front bank (cylinders 2, 4, 6) feel strong and fast while the rear bank (cylinders 1, 3, 5) feel weak and slow but still present. The question is what has to happen to make three injectors pulse weakly all on the same bank (and same receiving fuel from same fuel rail????

 

For wiring, all injectors have a common power wire (black/red) running to a junction box then to 12 volt power. The injectors always have power when the ign switch is on. The other wire from the injector goes to the computer. The computer activates each individual injector by grounding this connection.

The computer does have different duration patterns for cold start, etc but the injector will either be powered or not (no varying of voltage), only on/off.

Suppose a low voltage condition could cause slow response or something to do with fuel pressure. Check for battery voltage at the injector black/red wires. You can power the injectors with 12v.

The pressure regulator is connected to the pump in the fuel tank. Access is from the top of tank (no need to remove tank). Remove rear bottom seat cushion to expose an oval sheet metal plate behind drivers seat. Remove plate to expose top of tank and access to pump.

The fuel rails are interlinked so one should have the same pressure as the other.

EGR valve is normally closed when receiving no vacuum. Carbon can build up can cause the valve to stick open. There is a trouble code for this condition of excess exhaust gas but it takes a few drive cycles to trigger.

Another test to see of the valve works is to apply vacuum to the EGR valve at idle. This can be done with a vacuum pump or bypassing the VSV valve. When vacuum is applied the valve should open (or may open more if not fully closing and not stuck) and cause rough running (even more if already rough) or kill the engine due to excess exhaust gas.

Injectors do leak but two at once would be strange.

One other thing is to check the EVAP hose running to the engine. This hose normally routes fuel vapors from the charcoal canister into the engine but for some reason may be routing liquid gas.

A gross check for leaking injectors is to unpower them by disconnecting the black red wire. Remove the plugs and crank the engine, the injector should not spray fuel and have no fuel signs in the spark plug hole.

Do you have a decent diagnostic info, if not send a private message with email address.

Most electronic parts can be tested reasonable easy rather then just replacing and hoping for the best. You will need a volt/ohm meter.

 

I am going to buy a noid light kit and check the injectors.

Where does the EVAP hose connect to (engine side)?

I have the FSM, if that is what you mean by diagnostic info?

I will be checking the injectors tonight.

 

Yes, you have all the service info needed.

For EVAP if you have the manual, check Section EC 2 and 3. Hose attaches to intake system after throttle plate. There is also a vent line running to the air cleaner. Long shot but?

Can also try cleaning the MAF sensor. The internet would have posts on doing this. It can be removed then cleaned with a spray. Use only a product designed for electronic cleaning and don't touch the sensor itself. A dirty sensor can cause issues but it does not tend to be sudden.

Inspect air intake system and MAF in case something got in to block it.

 

thanks for all your help. it looks like i had the plug wires installed wrong on those cylinders. i am an idiot!