1999 Toyota 4Runner Code PO302 - misfire on #2

D MCCORMICK

MEMBER
1999 TOYOTA 4RUNNER
6 CYL
2WD
AUTOMATIC
166,000 MILES

Have checked everything - coil, compression, plug & plug wire, smoke test. Two technicians have checked with their computer plug-ins.

When start after sitting for several hours will run fine EVERY TIME, like every morning no matter how far I drive. When start after stopping for a short while, it misfires on cyl. #2, and will keep misfiring until I stop; if start again after a short while, will still misfire. Mechanic says it is either a bad injector (70% sure) or the computer. Seems to me like a computer or electrical problem. What does it sound like to you? Can the computer be reset?

6 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Hi d mccormick, Welcome to 2carpros and TY for the donation.

Have the mechanic check the injector on no.2, camshaft and crankshaft position sensor.

Resetting it-remove the EFI fuse for 10secs and see what happens

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Saturday, May 15th, 2010 AT 4:18 PM

D MCCORMICK

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4 POSTS

Is that checking BOTH the injector AND the camshaft & crankshaft position sensor?

To work on #2 injector the manifold has to be removed. How probable that this will fix the problem? Is this a guess or from experience with that particular problem previously? Is this a process of elimination?

#2 is getting spark all along; the fuel quits flowing.

I won't be able to check with my mechanic until Mon. Or Tues.

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Saturday, May 15th, 2010 AT 5:42 PM

RASMATAZ

MECHANIC
75,992 POSTS

A misfire on a specific cylinder should lead the tech to check the compression/spark plug/injector for that cylinder. The injector resistance and fuel flow has to be checked out to rule it out

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Saturday, May 15th, 2010 AT 5:55 PM

D MCCORMICK

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4 POSTS

The compression and plug and wires and coils have been checked. Would the injector cause the problem as described - runs fine initially EVERY time but misfires when started up after a short shut down? Is it most likely the injector or an electrical/computer problem?

The #2 injector is under the manifold - have to remove it; if the injector is the most likely problem, then fine. Don't want to waste all the time and money chasing something that might not be the problem.

Thanks for your patience - the two other mechanics could only speculate on the problem.

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Saturday, May 15th, 2010 AT 8:19 PM

RASMATAZ

MECHANIC
75,992 POSTS

Try reflashing the computer and see what happens-nothing were right back to the injector, seal, its circuit and the computer. I'm sorry this is as far as I can go on this P0302