some engine problems 90 4runner

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Feb 1, 2011
Mesa, AZ
so i got my motor replace about 2 months ago after the old one took a Sh!t. lately i have been having the problem of a huge mpg loss, loss of power, low idle, and when i hit 2800rpm it jumps up in speed like it had been blocked at under 2800rpm. not exactly sure what to look for at this point. I have chopped my exhaust right after the cat, could that be the problem having less backpressure? By the way its the 3.0 v6 guys!
nobody can take a guess?):
Where to start.....?

Let me first say that I know nothing about the 3.0, but you gotta start with the basics. You say lately, is that ever since the new motor was installed or some time afterward?

1. Is the CEL on?
2. Rough Idle could be a vacuum leak, or several vacuum leaks.
3. Is the timing correct?

It sounds like there are multiple factors in play here instead of just one bad part. But then again I really don't know. Did you install the engine, or did someone else?
cel is on
havent checked timing or vacuum leak
i will do timing today, what do i do to easily check for a vacuum leak? do i spray starter fluid over hoses and when the engine revs thats where the leak is?
Easiest way to check for a vacuum leak (won't catch all of them, but is a good starting point) is to listen for the release of pressure when you remove your gas cap. There should be a 'whooosh'. If there isn't, you definitely have a vacuum leak.
sprayed starter fluid over all lines and nothing happened, replaced nasty air filter and it helped a ton, better idle, more power, i guess its the little things you shoould try first huh? thanks for the help guys, im still gonna check timing tomorro!
do you know when the last time the fule filter was changed? a clogged one will kil performance. and check that CEL depending on the code the ECU will freak out and go in to safety mode (ie retard timing and increase fuel and limit revs) the 3.0 is famous for having a false code for knock censor wich is code 52, the wires on the censor have a tendency to fall out and give a false reading,

so before checking your timing i recommend checking that CEL :wrench:
thats my next thing to change is the fuel filter, and yes it is throwing a cel code 52how do i check the wires? where is the knock sensor???
Up under the manifold. :eek: The good thing is it is likely the wires to it, not the sensor it's self. I do see allot of comments on being very careful of the sensor it's self as removing the wire connector from it can damage the connector on the sensor.

Google "3vze knock sensor location" without the quotes. Lots of threads will come up.

3VZE knock sensor WIRE - YotaTech Forums
Check it with vacuum gauge see what your engine is doing at idle and when you rev it up,check for clogged cat. converter.check basic timing and also valve timing (timing belt).

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