2004 Toyota Matrix misfires and injectors keep failing

Just keep in mind that service managers are not necessarily the best techs. They specialize in customer service, not in auto mechanics - an certainly not unusual engine problems.

If you have an oil issue (maybe rings maybe valve stem seals) it does not necessarily affect all cylinders and can easily leak enough to both ash up a plug and clog up an injector withou making it obvious on the dipstick.

Did you happen to get a clue as the the numbers from when the compression was tested?

Apparently he was formerly a Toyota tech, but…

No, I’m pretty sure the only notes they have are the ones I provided above. I.e., no specifics on the compression numbers.

Thanks for the thoughts on the oil issue. We’ll see what happens in the next few days.

Sorry for the multiple posts, but…

Photo of all 4 plugs attached.

#1 plug

#2 plug. New at 64,560.

#3 plug.

#4 plug.

1, 3 and 4 are original to the car. All 4 were removed at ~92,000.

One more. #1 (original, ~92,000) on the left, #2 (~28,000) on the right.

I think the trouble is with the ECU as others have already stated. The ECU may be turning the injector on too long or there may be a problem with a current limit resistor for #2 injector inside the ECU. If I was working on this I would use a O-scope to compare the signals across the injectors. It will show how well things are working.

All the plugs look within normal to me.

#1 is a little fuzzy, but it’s got a lot of miles on it.
The iridium electrodes can hold up for 100k miles or more, but the rest of the plug can pick up deposits just like a conventional one.

None of the center insulators show signs of running rich (would be dark).
No sign of oil burning.
#3 and #4 look like they run a little cooler than the others.

I plan to change the plugs in my '06 Matrix at 50k mi.

Update…after a bit of push and pull with the dealer, they agreed to contact a Toyota FTS for ideas. Apparently the FTS agreed there was likely a problem and suggested some tests. They also got approval to (tentatively, anyway) cover the cost of repairs. I took it in yesterday (Monday) morning and they still have it today. I just spoke to the repair adviser…didn’t get all the details, but it sounds like they have the head off and have noticed an issue with oil consumption on #2. “Block” was mentioned, but I didn’t catch the context. Apparently they need parts, and are looking at having it ready Thursday or Friday, including the injector. I’ll post again when I know more.

Got it back today. Notes:

“Cause: Found #2 cyl. burning oil, and #1 inj. bad”
“Correction: Replaced short block and all related seals and gaskets
Also replaced bad inj
120101 10.4 combo k .1 L .2 C 6.2 T1-87 T2-50”

Here are the parts they put in:

11400-22531
OEM 2005 Toyota Matrix Short Block Assembly

04111-0D172
OEM Toyota GASKET KIT, ENGINE O

23209-0D040
OEM Toyota INJECTOR SET, FUEL

00272-SLLC2
OEM Toyota SUPER LONG LIFE COOL

00295-00103
OEM Toyota FIPG OIL PAN

90080-31049
OEM Toyota SEAL, TYPE T OIL

90915-YZZF2-DS
OEM Toyota FILTER S/A, OIL

00279-1QT5W-01
OEM Toyota OIL,MOTOR 5W30 QT W

The part names are from toyotapartszone.com.

No charge. The bad injector on #1 was because they had previously moved it from #2 for testing.

For anyone still following…

The car has been driving fine, and no check engine light, but mileage seems down. I called the dealer and they said that is to be expected with a new engine. Is that the case? When should I expect that it will get better?

How much change in mileage are you seeing? If it is more than 5% I’d say there is a problem. Perhaps the coolant sensor may be bad.

I’ve only filled up a few times since getting it back, but while I used to get somewhere between 300-400 miles per tank, now it seems like I can’t hit 300, even with mostly highway driving.

Check the plugwires and make sure they are seated well. I would also have the coolant sensor for the ECU checked to make sure it is working as it should be. Using a scanner should show if the coolant temperature is where it should be and the sensor is working correctly.

No plug wires - the coils are right on the plugs.

I’ll keep the coolant sensor in mind.