Hesitation at 3500-5000 rpm

Hello all,

I am having a hesitation on my 2000 4Runner(3.4l v6). Whenever it gets past 3k rpm it surges and hesitates. Anyone experienced this before? All help is greatly appreciated.

It has a fuel filter with about 4k miles on it, and I just replaced the TPS as it was throwing a CEL. I'm thinking the plugs need changing, but I'm concerned it isn't the reason for the problem.

Thanks all.

 

Have you checked the fuel pump? You said you changed the fuel filter, if that filter was clogged it could have made the pump work harder and could be burning out due to the stress

 

How would I go about "checking" the fuel pump? I'm assuming if the fuel pump was going out it would whine or do other things? Thanks

 

It may not necessarily make any noises, but one way is to check the fuel pressure at the injectors and see if it’s in spec, then rev up the engine and see if it maintains pressure or falls on its face. I’m not sure what the spec is for the pressure but it should be somewhere in the 30-50 psi range

 

Also checch the timing cog for play. I've seen the woodruff key wear a little gap and this play causes the timing to go fubar.