Error Code P0304 and P0303

W

wht2006tacoma

New Member
Ladies and Gentlemen: If I accelerate at a slow and steady pace, to "any" cruising speed and maintain that speed I can run smooth, with just a little bit of roughness every now and then forever. BUT, IF I press the accelerator too hard to maintain speed up a grade or to pass out slower moving traffic all hell breaks loose. All power is lost, the engine bucks like a bronco because the timing has been lost and the check engine light blinks. If I pull over and turn off the engine, wait a few minutes ( 5 minutes or so) before I start the engine again the engine runs as before. This sort of episode will happen when it is HOT. I have not yet tried this when it is cold but I imagine it would do something similar when it is cold.

This will happen after coasting down a grade and pressing the accelerator to pick up speed. This will happen from "what ever speed" I start at or drop down to. Once timing has been lost I must stop, turn off the engine and wait before it will run smooth again.

My mechanic tells me the engine is running (timing wise) just fine. I damaged a spark plug because of this activity. I have changed the coils ON EACH PLUG "TWICE" and this loss of timing and power still happens as above. The only codes I get on my $50 code reader are P0303 and P0304 and a smog alert/warning.

I have gotten to the point where I can tell when it is going to happen and have developed a technique of letting off the gas just before the power is lost. This prevents all hell from breaking loose and keeps the engine running smooth.

Does any body have any ideas as to what is causing this problem.????


Thanks for any and all suggestions.
 
wht2006tacoma said:
Ladies and Gentlemen: If I accelerate at a slow and steady pace, to "any" cruising speed and maintain that speed I can run smooth, with just a little bit of roughness every now and then forever. BUT, IF I press the accelerator too hard to maintain speed up a grade or to pass out slower moving traffic all hell breaks loose. All power is lost, the engine bucks like a bronco because the timing has been lost and the check engine light blinks. If I pull over and turn off the engine, wait a few minutes ( 5 minutes or so) before I start the engine again the engine runs as before. This sort of episode will happen when it is HOT. I have not yet tried this when it is cold but I imagine it would do something similar when it is cold.

This will happen after coasting down a grade and pressing the accelerator to pick up speed. This will happen from "what ever speed" I start at or drop down to. Once timing has been lost I must stop, turn off the engine and wait before it will run smooth again.

My mechanic tells me the engine is running (timing wise) just fine. I damaged a spark plug because of this activity. I have changed the coils ON EACH PLUG "TWICE" and this loss of timing and power still happens as above. The only codes I get on my $50 code reader are P0303 and P0304 and a smog alert/warning.

I have gotten to the point where I can tell when it is going to happen and have developed a technique of letting off the gas just before the power is lost. This prevents all hell from breaking loose and keeps the engine running smooth.

Does any body have any ideas as to what is causing this problem.????


Thanks for any and all suggestions.
Click to expand...
Just shooting ideas here... did you change the plugs when you changed the coils? Old dry hoses causing a vacuum leak? Fuel pump trying to die? Didn't pop a code but, crank position sensor?

*also reading on TW where a few guys have had to replace a head gasket, wasn't a noticable leak or anything, tech spotted a drop, literally a drop, of coolant inside the cylinder with a scope. Compression tested ok but still caused a misfire. Not intended to frighten you, just sharing what I've found on this topic.
 
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I'm no mechanic, but I'd say your distributor is worn out. I'd be willing to bet the gaps on your distributor have increased, causing a higher current resulting in over heating.
 
Plugs are good. No vacuum hoses or distributor to worry about Model year 2006. Mechanic did talk about coolant issue. THAT may be my problem. Thanks for the input guys. I really appreciate it.
 
wht2006tacoma said:
Plugs are good. No vacuum hoses or distributor to worry about Model year 2006. Mechanic did talk about coolant issue. THAT may be my problem. Thanks for the input guys. I really appreciate it.
Click to expand...

After reading a bit more about head gaskets and misfires, it would seem to me that it is your head gasket. Must be a very small leak that occurs when your truck gets hot enough (high coolant pressure). Sounds like the coolant leaks is leaking into the cylinders which would be 'polluting' your air/fuel mixture ultimately resulting in a misfire.
How many miles/kms on your truck? I also have an 06 with higher milage (230kms) and now you got me worried one day i'll have the same problem. LOL.
 
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