EPICjurneez

Within a period of a few years, I've posted my motor's specific performance issue twice. Why doesn't it get 26miles/gallon? I've usually received the same basic-to-fairly technical explanations, or the encouragement that I'm getting the miles/gallon I should be.

This time I'd like a different form of assitance from anyone who is willing to share. If you know of any 22re mechanic "Guru" who stands head and shoulders above allllll other 'guru's, or any blessed person of that sort, COULD YOU PLEASE TELL ME THAT PERSON'S name and Phone #?! I would like to personally speak to him.

If you're curious?? My 94 pickup 4x4 with 22re (recently dropped in a newly rebuilt block by ATK) barely achieves 20 mpg. That may be considered great if I was a lead foot, but I'm not. I drive the truck very slow without lugging.

1. These mpg stats are in southern CA with 87 octane. When I'm in higher elevations in Utah and Colorado, running 85 octane, plus running AC, driving steep mountain roads, same driving habits as in CA, I achieve 24 to 26 MPG! How is this?
2. The engine lags noticably (by me and my wife whose in the passenger seat) when the engine rev's above 2000rpms and up to appx 3000rpms. Why's this? Even on the newly installed motor. I asked the people who installed the rebuild motor but he didn't know!
3. My engine idle is inconsistent. Once warmed up, it should idle around 750 to 900 rpm ( I forget exactly where, I just remember when my truck was new in 1994 and the idle was surely pinned somewhere in that rpm range, unless the AC was on). Now, and for at least 9 years, the idle drops down to 400 rpms sometimes or sits a lot higher at 1400 rpms. The latter usually happens after long road trips.
4. This comes and goes... the engine idle would surge up and down from idle to 1200 rpm for no reason!

Like I previously stated, I've received many speculative theories but no one has given me anything that has made a difference. Obviously, I still have the same issues. The problems may all be related. Perhaps they are of completely separate origins. I've had local 'Gurus' have look but none could give me a solid explanation. Based on all the mysterious run-around, my guess is some electronic aspect of the system is malfunctioning...Where? Dunno.

So, if you know that special someone whose truly 22re Master and even knows the electronic aspects, please let me know how I can contact them.
Thank you all, very kindly.
William

Flash319

These engines are not that complicated. Sounds to me like you have a leak on your intake track (AFM-throttle body pipe) and also may have sticky AFM. Again all speculative and it is hard to do anything else without looking at the truck. May also have some vacuum lines not right or a vacuum leak.

Like you have heard, 20mpg is about average. I can make my MPG drop about 5mpg or more just by going 10mph faster on the highway. If your engine is running good and your brakes are not dragging at all the best I have ever got is about 23mpg going 55mph for a full tank.

Your AFM is everything to these motors, then TPS in that order. If these 2 systems along with a good O2 sensor then you are the best your going to get.

Also was the 24-26mpg in the same truck? same tires?

The idle is controlled by coolent temperature on a diaphram under the TB. If your coolent goes low you will get a high idle. If your idle is to high while the throttle plate is closed the you will get the bouncing idle. The drop to 400 is normal for these motors and is because of the AFM system. It is mechanical and does not operate the same all the time. If you have a hot engine and then start it up sometimes the flapper in the AFM does not open very far and you get a low idle.

I consider myself pretty good with these trucks but you will need someone to physically look at the truck. For all I know you have duct tape holding everything together

EPICjurneez

You've raised more insightful points than I've heard till now. Thanks. My vocab is not on par with yours. what is afm and tps? where do I find these and other items you mentioned? what do they look like?

Yes...same truck and 31 bfg at's (they was a bit more tread tho).

Thank you for your time!
Do you have any insight on why I had better fuel economy with the contrasting conditions of thinner/drier air and lower octane fuel?

William

Flash319

AFM = Air Flow Meter, this is on top on the air filter and tells the ECU how much air the engine is pulling. This has the greatest effect on how much fuel is added to the engine. Therefor the tube running from the AFM to the throttle body must not have any leaks in it or you will get a bunch of problems (bad idle, poor acelleration....

TPS = Throttle Position Sensor, it is on the side of the throttle body and the throttle plate turn the guts of it. This tells the ECU how much throttle you are applying.


Octane has no bearing on fuel consumption as it is a combustion inhibitor. Octane prevents fuel from igniting under pressure without a spark. Ignition without spark causes "spark knock". High performance engine uses higher octane because they are running high compression (usually over 9.5:1) or high ignition advance. The 22re has neither of this conditions so low octane is all that is required. I think the owners manual calls for 86 and up though.
The thinner air will lean out the mixture thus you would get better fuel economy, a bit.

The lag that you are getting could be many things and could only be diagnosed by driving it. Usually a lag comes from improperly set timing, AFM/TPS not working properly, fuel pressure problems (regulator and vacuum hoses associated with them), bad spark plugs/wires/coil, plugged cat converter, poor injector ground wiring, bad injectors..........

olharleyman

AFM = Air Flow Meter - located just before your air filter box shown here just before the filter and after the blue rubber piece


TPS = Throttle position sensor - on passanger side left side of fuel intake it is black and silver and has a big electrical plug going into it. Kind of hard to see but it is pitch black outside and I was going by feel lol but just look where this water inlet is and you will see the plug going into the black piece here my is out but you can get an idea from here.

EPICjurneez

The ecu sits behind the passenger side kick panel right?

Same truck and tires... I blew a headgasket (again). I had that atk rebuilt 22r installed. Along with the install, I received new everything (plugs, cables...and what comes with a new engine, like water pump...even a new radiator). So, after all that newly replaced stuff, it still runs very similar to my old motor when it was 'healthy.'

So, that leaves the afm and tps, and even maybe the ecu that is left suspect, right? Maybe not the ecu. Should i try buying and replacing afm/tps?
William

myyota

A throttle position sensor can go bad and cause many problems, like an eratic idle and acceleration problems, and im sure it can even affect gas mileage if it gets bad enough. I replaced the TPS on my 86 4Runner because it was original and after 23 years of use i figured it was a good idea.

EPICjurneez

What difference did the tps replacement make?

ovrrdrive

The master you're looking for is probably Ted at engnbldr (engnbldr on the forum). Email him or PM him on the forums and he'll probably show up for a post or two. The man knows his stuff.

As for mpg, there really isn't much you can do when the truck was rated at 18mpg average from the factory when it was brand new. That is unless you want to ride on wooden tires or something to reduce friction...

Flash319

I would say it is not the ECU. If the engine runs then the computer is fine.

mojoman

http://personal.utulsa.edu/~nathan-buchanan/93fsm/ go here it is the factory service manual. get yourself a multimeter and start checking all your sensors. it shows you how and on the 22re is quite easy. I also just did a rebuild on my truck ran like a dog. I traced it to a weak fuel pump, but was able to use the manual to rule out all the other things.

Dirt Driver

Thinner air would cause the mixture to be richer, but the EFI compensates for air density, so altitude makes little to no difference in the actual AFRs. What does make a difference at high altitude with thin air is less aero drag and reduced engine pumping losses. Power goes down, but when the engine is running right, most get better fuel economy as altitude goes up.

26mpg is the highest mpg I have ever heard of a 22R-E/4x4 getting. I would have one if I could get 80/20 highway/city mileage like that!

Flash319

My thinking was that for a given RPM you would pull a certain amount of air. The ECu would then add fuel but this would cause a rich condition because the air is thinner. The O2 would then tell the computer that the mixture is rich thus causing the ECU to lean out more often then not.

Either way the ECU should be holding the mixture constant so the air should not have much effect. Unless is was a carbed motor. Then you run rich all the time in thin air.

EPICjurneez

can you recall the sensors?

did you replace the fuel pump? what was your result?
Thanks

muddpigg

iTrader: (1)

This post has a lot of knowledge and some very good ideas. So let me through in my $.02. I've learned that these engines can have similar problems but from different sources.

Are their any trouble codes stored in ECU? My truck is older so don't know if procedure is same for pulling codes.

Were the injectors cleaned at time of rebuild install?

Was the EGR valve replaced?

New vacuum lines?

New O2 sensor? what brand? Brand of plugs? as some brands don't like Toyotas.

Do you trust the garage that did the install?

I don't know much about ATK I opted for a different rebuilder on my last engine install, this is my second. You can use a block off plate to test the EGR, I found mine to cause an idle problem in my truck. So being the sometimes thrifty guy I am I cleaned it out no more problem.

After the install did you get you emissions checked? if so did they give you a gas analyzer results? That may help trouble shoot too.

Flash319

Good point about the EGR. I have never had a problem with one but that should be one of the first places to look for idle problems.

myyota

In my case it didn`t make any diferance, i just replaced it because it was 23 years old and had over 200.000 miles on it, so i just figured it was a good idea.

xzyragon

i get anywhere from 17-20... then again, i drive a little on the "aggressive side" and i have to go up a steep a** hill every day to get to work.

Im not complaning. Its better than what a hummer gets.

herdnerd

I really don't know what I'm talking about so feel free to ignore my comments.

No one has asked what gears you are running with the 31's. I am just guessing that if you regeared or went back to stock size tires you would see an increase in MPG. It may not pencil out to regear however.

There are probably many factors contributing to the higher mileage in the mountains. Have you considered that running in the mountains you were downshifting more to make it up hills and such increasing RPM's? Where is the peak torque for the 22re? Doesn't an engine run most efficiently at peak torque, all other things equal? I think people assume that lower RPM's will increase MPG, but that is not always the case.

EPICjurneez

I dont know if all those parts were replaced. I think only the basic necessities that come with the rebuild process.

Garage is a trusted local shop. Probably not 'gurus'

dunno what the EGR is (sad, I know). I've heard of it before. what is it and is the process of testing it and cleaning it out complex?

I got it smogged straight after the rebuild. I'd have to go dig up the printout.

what next? I'm a frugal guy too.