I have a missing/hesitation problem with my '98 Sienna. (150,00km -
98,200mi) This is an odd problem that has both the local Toyota shop and a very skilled independent mechanic stumped. When first started there is a pronounced miss. The miss settles to a hesitation after the engine is warm and disappears altogether after about a 1/2 hour or so of driving. The miss/hesitation disappears when shifted to Neutral and re-appears in either Drive or Reverse.So far we've replaced spark plugs and wires. We've had it tuned. Mechanics can't recreate the problem in the shop (it's in Neutral) although they say they get the problem when they take it on a test drive. Computer analysis comes up blank.
I've had everything from fuel pump to transmission problems suggested as possible causes. I don't want to get taken to the cleaners as mechanics play guess-the-part-to-replace.
Has anyone run into this problem? Any suggestions or ideas on a cause or fix? Thanks in advance for any ideas.
JD Lloyd