1MZ Miss

[KY-Ron]

This one has me stumped. I've got a 96 Camry with the 1MZ. started missing the other day giving codes P0300 P0301 P0303 and P0305, Back bank is missing. I've checked wires. plugs, and vacuum hoses. Runs great in park or neutral, put a load on it and runs really roough. I've checked everything I can thing of, Any suggestions or other ideas would be greatly appreciated. Being new on this board, I think it is great.

[Nick]

check the power connections and ground(s) for the ignition coils, if they're not grounding right on that side it would cause it to miss...

[bluedemon]

it will????? hows that happens.
my 1990 corolla doing the same thing ,im only running on 3 cylinder,took the damn thing apart like so many time and still missin on cylinder #4 help..........!!!

[Nick]

but your rolla only has 1 coil

[KY-Ron]

Check wires and ground A OK. Wires have around 20K as do the Bosch 4 Plus plugs. Coils that fire 1 3 5 also fire 2 4 6 No miss on that bank.

I don't know a lot about the fuel system. Can something be off on that bank as it seems to split by bank. I need help from a soomeone that knows the fuel system I think?

[chronoti]

your cam sensor might be off, the second fuel rail is under the intake if your to check the injectors or to clean out the rail you have to remove the intake to get too them.

[ekpolk]

Originally posted by KY-Ron
Check wires and ground A OK. Wires have around 20K as do the Bosch 4 Plus plugs. Coils that fire 1 3 5 also fire 2 4 6 No miss on that bank.

I don't know a lot about the fuel system. Can something be off on that bank as it seems to split by bank. I need help from a soomeone that knows the fuel system I think?

OK, I'm getting confused. Isn't the 1MZ-FE a coil-on-plug engine? My understanding of this setup is that each plug has its own coil which is fired individually by the computer at the proper time. This is a photo of my engine I took this evening. Note the green circles.



Did the earlier 1MZs not have this setup? Anyway, back to the main point, I was thinking that the problem being isolated to one bank suggests a "physical" problem located near or associated with that bank. Fuel rail, exhaust, or bank-specific electrics might be good starting points.

And this is what it looks like with its "hat" on. . .

[KY-Ron]

Your right the engine has coil paks on the front bank. The pak that fires cyl 1 also fires 2. The pak that fires 3 fires 4. 5 fires 6.
That is you have 3 paks firing 2 cylinders each.

Whats this cam sensor that fires the injection? Where's it located? this sounds more like the problem i'm having. Are the cams off? I had the belt changed about a month ago.

Thanks to all!!

[chronoti]

well when they changed the belt the cam might be off by about a notch or so, also there a cam sensor (since there no distrobuter) to let the engine know when it has to fire, if that sensor is bad or reading wrong then it's more like the timming is off. i'll try and post a picture from my haynes manual later tonight for the cam sensor.

[kmorphosis]

Also.. not sure if this will apply to u or not, but last week my sis's 4bang camry was doing what sounds like the same thing. She had a lot of carbon buildup in her engine. We had it cleande out and all, but now she has to be sure to use gasoline with an additive or else she will have the same problem again. She only has 80 on her 97. But my 1MZ and my dads MR2 both have over 170k and neither of us has had this problem. This may or may not help you.

[repinS]

Originally posted by ekpolk
OK, I'm getting confused. Isn't the 1MZ-FE a coil-on-plug engine? My understanding of this setup is that each plug has its own coil which is fired individually by the computer at the proper time. This is a photo of my engine I took this evening. Note the green circles.

my uncle's '94 (sludged, no less) is like that, so it's safe to assume ALL 1MZs are like that.

[KY-Ron]

Thanks All, Its back to the drawing board, First I'm going to pull the front engine cover and see if the timing marks still match. If they match up to the dots, I have to assume the cam sensor is somehow off or bad. If both banks cam sensors are the same could I switch the front and back bank sensors and see if the misfiring switches to the front bank from the back bank???

[KY-Ron]

Thought all would like to know what was wrong. Tested and checked cam sensor it was OK. Next took front of engine apart to check timing belt. The back cam was off by a tooth or two. Reset belt and started all is now OK.

Again thanks to all who helped diagnose this problem.

[2wickedtoyz]

Originally posted by repinS
so it's safe to assume ALL 1MZs are like that.

some 1mzfe motors came with 6 coil packs others came with 3.