By March 31, 2008 0 Comments Read More →

2003 Toyota 4 Runner Harder To Start Than Normal?

Reader Question

My 2003 Toyota 4 Runner V6 (85,000 miles) has begun (a new problem this winter) to show hard starting after years where it showed quick start up with just a touch of the ignition key contact turn. Last night it cranked ten times and didn’t catch. Next, it cranked 6-8times and very faintly caught and very slowly began to run as if starved for something. (I resisted pumping the gas.)

Gradually (20 seconds) it came to life and ran just fine after that ( doesn’t die at idle or such.). I was concerned it wouldn’t start at all. The power is fine and it runs smoothly after it starts. I live at 8700 feet elevation and visit often at 9100 feet elev. The problem is worst at these altitudes.

I have added HEET and use 87 octane ( they sell 85 octane here as “regular”) without help. Is this problem most likely oxygen sensor failure (does it wear out?) ?; computer problem with air/fuel ratio problem? air filter? battery (its the original one); timing belt (due at 90,000), bad plugs? or… I would greatly appreciate any ideas or suggestions.

Thank you



Hey Russ,

I always start with the simple stuff in situations like this, clean the throttle body, make sure there are no obvious vacuum leaks under the hood and that the air cleaner housing is installed properly, check spark plugs, replace fuel filter, check ignition coils, check fuel pump pressure etc. etc.

I would bet you have a dirty throttle body, which can easily be cleaned by your mechanic or fast lube place. I would start there first. You are due for new plugs, so that would be my next step if a clean throttle body still gives you trouble…..hopefully that solves the problem.

Here is more on the throttle body


Austin Davis

Posted in: Toyota

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