Bad Gas Mileage - 94 Toyota 4X4 Truck? Any Ideas?

[steelzebra]

so, my '94 toyota truck, 4 x 4, is now getting worse gas mileage than ever. as well as high pitched squealling only when the truck is NOT under load, stalling while slowing (exit ramp of highway, stop lights)- yet starts back up immediately, and now a subtle gas smell upon starting if i have the air or heat on...

changed the head gasket a year and a half ago, head was milled. new starter, new clutch kit. new belts, adjusted properly. new radiator. new plugs and vacume hoses. is this a vacume problem? if so how do you find the leak???
thanks for any suggestions or thoughts

[1 bad tacoma]

Vacume leaks are very tough to find they make a vacume gage where you can hook up to some of the vacume lines but that always don't work. This problem to me don't sound like a vacume leak but I have been wrong before is check to see if your cat is stopped up that can make the truck stall but the gas smell I really can't say unless you have a bad injector that might be leaking by

[toyotafan]

any resolution to this?

[angieross269]

vacuum leak or fuel injectors? bad injectors can cause terrible gas mileage, shaking at idle as well as stalling, misfiring, rough starting, and running rich can def give you a smell of gas...

[bebtunes]

have you gotten this figured out or still trying?

[toyotafan]

vacuum leak or fuel injectors? bad injectors can cause terrible gas mileage, shaking at idle as well as stalling, misfiring, rough starting, and running rich can def give you a smell of gas...

yeah, I agree having a bad vacuum leak can cause these issues and that also can be a nightmare to get solved. The injectors can be cleaned for the most part, just try a few cycles of fuel system cleaner and see if that picks up.

RXP! Try this, it's one of the best on the market. You can usually call around and ask for it, it's almost always stocked by one or two of the "Autozone" type of places and they will usually hold it behind the counter. Get a bottle (about $10 for a small bottle) and mix it according to the directions. Then run a hundred miles or so and see if it picks up. If not, do the whole cycle again with another bottle of RXP. You may have to run three or four bottles, if no improvement then move onto something else as a carbon build-up is not the main problem.

[MuddyTacoma]

How many miles on this engine? I'm guessing it's a lot.

I also like using the RXP, or something similar like SeaForm to break down the carbon build up inside the engine. That's usually the first thing i do when I get a used vehicle and almost always I pick-up an extra 1/2 to 1 MPG over what I think it would have been.