Team420

any oil loss? Mine was getting really bad mileage when my valve covers were leaking, as they created a vacuum leak as well.... put some new gaskets in there, and I was back up to my 17mpg as usual...

o... and I blocked off my egr years ago, no ill effects as of yet, and no change in fuel consumption, or power...

Kiroshu

Unless you do alot of high way driving you won't notice much from egr.

Bako88

I would say fuel loss could be the culprit. I'd want to test the cold start injector or other fuel leaks.

I also wonder why there's so much crud in the intake after Seafoam. Does that suggest it doesn't work as well as we're supposed to believe?

eddygrant

it sounds like your ecu is over fueling the engine i just put a turbo on my 22re and some 460cc injectors and i had to take off the top of my air sensor and tighten the spring and that helped alittle but if you really want to get accurate fuel mixure get an air fuel ratio guage and that helps alot and it really lets you get and idea of how much your accually in the pedal.

Ezrider_92356

i think to be getting that bad of fuel millage and not having the truck run like utter crap you must have a external fuel leak

chevydan04

A little update...

I decided to start with my intake plenum and in the process needed to remove my timing belt cover, I discovered a very cracked belt that looked like it had a ton of miles on it. I think it may be possible the truck jumped timing at some point.

I have inspected all fuel lines from tank to fuel rail with no notice of fuel leakage.

Also in the past i have disconnected the cold start injector, no difference in gas mileage. Just made it almost impossible to start the truck.

The only time the truck ran like crap was when I was sitting with it in drive and I was stopped. Also it has always seemed a little sluggish but I figured thats why everyone called the the 3.slow...

As far as SEAFOAM goes I am assuming it took alot of crud out of the intake plenum and now I am just left with the left over stuff. I seafoamed about 200 miles before I took the plenum out.

I don't have any oil leaks at all. my valve covers look great.

Kiroshu the only thing I have not checked on your list is the TPS. As far as exhaust leaks go I have a slight leak its in the muffler, after the CAT.

I also put a new CAT on last winter.

Last year when trying to set the timing I did have an issue I could not get the mark to hold still, I jumped the 2 terminals, and the mark would just slowly make it way around. Could've been a crapy timing gun, but it was a nice Craftsman that my buddy and I used on a bunch of different vehicles just mine acted up.

garyeshultz

I don't have any advice to offer but I put up a thread today for my '87 22re which I've been having similar problems with. 10mpg with no check engine light...not a clue what it could be. Just hoping that people will continue to throw in their 2cents in here and there until we can get'r figured...

Kiroshu

Well I'm assuming your going to replace that worn timing belt? did you bring it to TDC and see if that belt has jumped a few teeth?

Over time and wear of the timing belt sometimes it will naturally jump a few teeth or too from stretching. In which case would cause performance issues.

Unless its leaking before O2 Sensor(s) the fuel economy should not be affected that much. But i would recommend patching it up as its kind of an annoying noise and also can have a slight performance decrease. (Exhaust leak)

I have a feeling that the issue now might lie in the Air flow meter. If its the original one and has never been tampered with its prob getting to a highly worn out point. The Air flow meter on these truck determines a high percentage of "fuel input"

The other big thing that determines a high fuel input is the TPS.

If you have a service manual or a haynes manual and a multimeter you can test to see if they are with in spec very easily.

chevydan04

Kiroshu

Yea I was thinking about the afm yesterday and the tps but like a dumb dumb I went for the hard stuff first. I do that a lot for some reason.

I got the new timing belt yesterday along with a tensioner and a idler pulley and some seals.

hopefully once I get it back together it runs much better and gets some decent MPG's

What should I honestly expect out of a 20 year old 4runner as far as my MPG's go

mwc0404

ok, so i got also ask here i have a 99 limited 4x4 and i used to get really good gas mileage then i was in a small wreck and it sat for a while. now the fuel mileage has reduced and the tranny is acting funny, (and by funny i mean it would run each gear all the way out before switching the first time through and then work fine after) i think ive corrected the tranny issue by changing the fluid and filter and blowing out the lines to the cooler and getting the trash out. but still not sure on the fuel mileage issue. Ive read through all thats been said here and i have done all the normal checks and replacements, i just in the last couple days had the C.E. light come on due to one bank running lean due to an O2 sensor going out. Any ideas or suggestions?