ROUGH & HESITATION

  • Tiny
  • CCross
  • 2001 Toyota Corolla
  • 115,000 miles

2001 Corolla - rough idle on initial start up in the morning, then clears up, then hesitates slightly on accelleration from a dead stop after that.

I've changed coil packs, spark plugs, MAF & O2 (upstream) sensors, & added a fuel injector cleaner.

Still have idle & hesitation problems - help!

Sunday, June 10th, 2012 AT 4:16 PM

5 Answers

  • Tiny
  • ASEMaster6371
  • Expert
  • 25,502 posts

I think you are on the right track with injectors. You need them professionally clean, not by an additive. Clean the throttle body as well.

Another issue with toyotas was carbon build up on the intake valves. A top engine cleaner done by a shop can be done to see if it helps. In a lot of cases, removal of the head and a valve job was the answer as carbon absorbs fuel cold and after it warms up, it will run ok.

Get a shop to verify this for you.

Roy

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Sunday, June 10th, 2012 AT 4:21 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,938 posts

Any trouble codes?

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Sunday, June 10th, 2012 AT 6:25 PM
  • Tiny
  • CCross
  • Member

P0300.

And it "consumes" oil (no leaks that I could find).

Thanks for the help!

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Sunday, June 10th, 2012 AT 6:45 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,938 posts

Multiple misfires. Check the engine compression and valve clearances apart from what Roy had recommended.

Oil consumption would often create a lot of carbon deposits if the intake valve seals are bad.

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Sunday, June 10th, 2012 AT 6:55 PM
  • Tiny
  • CCross
  • Member

Will do - thanks again!

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Sunday, June 10th, 2012 AT 7:54 PM

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