15mpg 22re, rough idle

[lledwod]

I have finally got my 1989 4runner 22RE 'on the road'. Took it for the 1st good test run yesterday, about 170 miles. It turned out 15.7mpg. It is a 5spd. I am confident that the chassis and gearboxes, wheel bearings etc. are fine, and not causing a drag. I feel that I should have gotten better fuel mileage though. I was driving 50-60 mph, mostly on a gravel road with a dog, a kid, the girlfriend and a bit of gear. The motor seems sound, (came out of a rollover). The tires are 235/75/r15.

The truck seems to run fine, and strong. Accept it has a rough and low idle, and sometimes stalls once it is fully warmed up. It'll idle fine, all day long when cool. (Well for an hour anyway!) The check engine light came on briefly, once, yesterday while driving.

I am new to EFI, having pretty much just been driving carbed 22r's for the past 20 years. My best ever mileage with them (4WD truck) was 25mpg, and my average highway mileage considerably higher than this 4runner, probably around 20mpg

So for now, my questions are, what to start looking into for the idle, and what mpg should I expect?

Thanks for any help.

 

[jprhome]

I don't have any personal experience with 22RE's but I do have some general knowledge over engines from my own experience.

I'd start by checking out the vacuum hoses to make sure everything's where it needs to be and all is in good health, usually these will cause idle issues and stalls.

other things to consider that usually will highly effect idle are ignition parts.
after purchasing my 3.0 4runner I just went ahead and replaced my distributors cap and rotor, I knew my rotor needed replacing soon because it was pretty knar.

Spark plugs and plug wires are another thing to consider if they seem old. when I replaced my spark plugs they had rust stains so obviously old as F*&%. not sure on when to consider replacing wires unless your not getting spark off a lead. I just didn't like how old my wires looked and picked up some NGK blues which ran me about $50 but you can get wires for around $25 or so that will work just fine, I just try to spoil her if I can.

usually on the TB there is a flat blade screw to adjust for your idle, consult your maintenance manual on specifics of idle RPM's usually engine warm in neutral or out of gear*

Hope this helps.

I'd also consider swapping out your fuel filter.

just on a note in my experience If you're getting any fuel smell from the engine bay like I was i'd check out the seals around your Injectors as these can get old and turn rock hard and no longer seal correctly causing fuel loss.

 

[penbergm]

Make sure the TPS is adjusted properly and if it threw a code, see if it is still stored.

 

[flyinhawaiian01]

First things first, check the codes.

Check timing, set it around 8-10BTDC, not 5º like the manual says, the 22re is happier with a slight bit more advance.

Set your tps, that will cause idle issues, as well as issues with the check engine light popping on randomly.

Set your idle with the set screw on the throttle body like the last poster said, once you get through the above checklist.

 

[jprhome]

Forgot a few other things to mention

Check your PVC valve(s) to see if they are moving freely.

Check your Throttle body also for carbon build and clean as much as you can possibly reach.

just some other things to check out since you did get a random code the other day is your O2 sensor but usually if bad the light would stay on.

not sure if the 22RE has a MAF (Mass Air Flow Sensor) not sure currently how to check it though. If you got a manual it should tell yeh or the web usually with an multimeter you can check to see if it's within specification.

 

[lledwod]

Thanks guys! All sound like good ideas, I'll just work through them. I'm just kind of burnt out on the truck, spent the summer going through the whole thing and replacing lots of stuff, and some fresh perspective is, well refreshing.