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01 Tacoma 3.4 P0300 also Cam position sensor, and other cylinder misfires HELP!

01-05-2008, 07:56 PM
I was getting ready to do a timing belt job on this truck just as preventative, it has 100k on it.. But suddenly the other morning, it started running rough and the CEL was on. It had a total of 7 codes. 2 random cylinder misfires, a camshaft position sensor code, and 4 other numbered cylinder misfires. I put new plugs in it, cleared the codes and restarted it. It still is running rough, I only let it run for a couple of minutes, and the CEL came back on. Random cyl. misfires again. Is there one thing that could do this suddenly? I am sure all three coil packs or wires all went bad at the same time. Could the Cam sensor be bad and do this? Or the crank sensor? Are there two cam sensors on this motor? Where is(are) it(they) located? Any help that anyone has is greatly appreciated!! THANKS

01-06-2008, 04:57 PM
Did you put a timing gun on it?

01-06-2008, 06:14 PM
No, not yet. Would I be looking with it just to see if it is way out of time? Like the belt slipped a tooth or two? It is still real rough idle, and if you try and speed it up, it coughs then speeds up, roughly.

01-06-2008, 10:12 PM
You can't adjust the timing, but if it is off or if one of the packs isn't firing the gun will show it.

01-07-2008, 05:05 PM
Well I have now put on new TOYOTA plug wires, and it is better, and will kind of accelerate now, but the Cam sensor code has come back after just a couple of minutes running. As I stated before, I was going to do a timing belt job on it anyway, so I took off the upper cover and wow, what I am seeing is weird. It looks like it had an antifreeze leak around the water pump, and has several years of cruddy growth, looks like crusty crap you might see in a cave. It is all over, probably about a cups worth of build up, especially on the CRANK sensor and related area. there is plated out crap all over the inside of everything, covers, cam pulleys etc. Tomorrow it is getting new cam and crank sensors, timing belt and idler pulleys, waterpump etc. I am thinking that all of that crap on the sensors has to be making it run bad. I will post results.

01-09-2008, 07:13 PM
Well it is running great now! The dried antifreeze crap did several things. The belt had actually slipped 4 teeth!! It had built up so bad, that it was on the crank sprocket, and the tensioner pulley has packed solid, so it slipped. It now has all of the sensors replaced, new waterpump, belt and idlers, and a new hydraulic tensioner!! SO, moral of the story, change antifreeze every two years, not five, and take care of leaks!!

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