Car is chewing too much fuel -
I have done a total engine change-sparks/oil etc. Toyota told me carbon catalyst -so i changed this But still Nochange to the fuel loss...Plse can some help/advise
Usually check enginw light will come on and set rich codes if its dumping to much fuel. Other than that have you checked for and fuel leaks any fuel odor?
I'd start by advancing the spark till crackling on acceleration...and back off as scoach~ for maximum combustion time...run with a clean easy-breathing air filter. Definately CHECK the operation of the EGR valve as this bugger can rob you of many miles to the gallon, how it's supposed to work is to open up when you take your foot off the gas, then close when you apply the gas....but it doesn't always work out that way, gets stuck half-open and you don't know the slow degridation of performance...wish I was there to do this for you, it's only two bolts and a vacuum connection or two, and could be done before supper~ they ain't that expensive to replace, either~ http://www.oreillyauto.com/site/c/search/EGR+Valve/02145/C0018.oap ?model=RAV4&vi=1357523&year=1999&make=Toyota
Cant adjust timing on this one roy. Not old school enough.
Dont think egr would cause this either it introduces inert gas into the intake once introduced into the cylinder it takes up space. That means less fuel and air mixture can be in there with it. So that would not increase the amout of fuel the computer adds it would actually be less. Plus egr does actually work at part throttle when cruising its meant to reduce combustion chamber temp. For emissions purposes.
So it works pretty much opposite of what mr roy said. Egr is not designed to work at idle, closed throttle (decel), or wide open throttle. Any other time is fair game. Not like it matters dont think this is the cause of your concern but false information doesnt need to spread around.
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