Question
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The text above is a follow-up to ...
-----Question-----Mr.Ritter,
Seems to me that Toyota should have known about the valves being out of adjustment or a bad injector. They did not suggest that a compression test be done. The truck has already been checked by two Toyota dealers and one has checked it twice. Also, wouldn't burnt valves or a bad injector cause an engine miss? One dealer showed me their hand held scanner that showed no engine miss firing, but did show that the idle dropped about 100 rpms when warm. I have not noticed the engine miss firing when I drive the truck. I certainly do appreciate your prompt response to my intial inquiry and your earnest desire to help me with my problem. Can any garage do a compression test and adjust the valves if needed? I have lost confidence in Toyota by not being able to diagnos my problem thus far.
Thank you so much,Jim
I have a 2003 Toyota Tacoma with a 2.7 eng, auto,4x4 with 54,000 miles. I bought it 6mos.ago. It has a very annoying, rough idle when the engine is at operating temp. When you put it in drive and hold the brake (like at a stop light) it idles ok for about 5 seconds and then the idle drops real low and creates a rough vibration that vibrates your feet and seat. I put it in neutral to alleviate the vibration but the idle is still low. The previous owner had the same problem because when I had toyota to check the problem I found out that they changed the plugs and did a fuel injection cleaning to cure the problem. Toyota says this is typical of this truck and there is nothing they can do to cure the problem. I don't know when the problem first started, but sounds like it must have been there since new if it is typical. Does this make sense? Some Toyota techs said to ignore it, some said to hold your left foot on the brake and right foot on the gas to keep the idle up,or put it in neutral. I have never owned a car that had a rough idle like this. Do you have any input on this problem?
Thank you,Jim
-----Answer-----
That advise is completely unacceptable and redicilous, this is not typical, even though these are not the smoothest idling engines. These engines have a habit of developing tight valves that will cause a rough idle, if the valves are left tight for any lenght of time they will start to burn and leak and cause this condition, I have seen this many times, another chronic problem is that a fuel injector may be sticking, this is also common on these engines, this will reqiure replacement of the injectors.
The first thing I'm going to suggest is that the engine compression be tested to see if there is a leak, if the compression is good I suggest replacing all the fuel injectors, if the compression is low on any cylinder have the valve clearance checked to see if any valves are too tight and have them adjusted and the compression retested, I have fixed a few of these by just readjusting the valves. If the compression on any of the cylinders remains too low the cylinder head will have to be removed and the valves ground and replaced as necessary. Just between you and me, I think the guy you bought it from already knew this and that's why he sold it. Let me know if more help is needed.
AnswerYes a leaking valve or bad injector would cause an engine miss, if that's not the case I would suggest looking at a possible idle speed control valve problem, it is located on the throttle body it may need to be replaced to solve the low idle condition.
