kinsey.clay

Hi everyone, I have searched long and hard on here and some other forums for info. Have definately found a lot of information but everyones problems seem a bit different. Here it is:

I bought this 87 runner earlier this year to drive when I got my license back. I am now down to the grind to get it to pass emissions before my temps expire so I can get plates. Have failed 3 times due to high CO now. HC's were high too but we got that down. Here's what has been done:

-New plugs
-New wires
-New cap/rotor
-New O2 sensor
-New Catalytic Converter (passed HC's and NOx with flying colors after that)
-Used MAF or AFM as everyone is saying it is here, came from piles of spare toyota parts, not sure what exact truck it's off, so not sure if that's the problem, but it fixed one problem, and you can hear it flapping so I know it's mechanically working.

ok for the details. Was running SUPER rich, crappy gas mileage, stunk real bad and failed CO at 110 (limit was 30!). My boyfriend has an auto shop and I also do some auto work so we had it at his shop. Found that the O2 sensor wasn't switching would just climb up to .9 and up and wouldn't go back down. My boyfriend checked the timing and it was up to 40! when turning it down to the 12* it ran terrible, and would die. I had noticed a while back that my fuel pump seems to ALWAYS prime when the key is on, which I thought was not right. Once we talked about that then we finally went investigating into this, this was after everything but the AFM had been replaced. We had also plugged in a computer from my friends toyota truck that i believe is an 86 and it didn't fix the O2 not switching. It had an O2 sensor circuit code that flashed the check engine light intermittently as well. So as we are trying to figure out what controls the fuel pump we knew the AFM had part in it and once we unplugged it the fuel pump shut off when the key was on. We found this used AFM and put it in and the O2 sensor started switching like normal and when we put the timing back down to 12* it ran great still! WAHOOO I thought, til I went to get emissions again....failed AGAIN for CO! this time instead of the 110 it went down to 56 but still almost twice the limit! Check engine light is off and it seems to run better, but it's not super powerful, but once again since I have owned it it's never been running right so I guess I'm not sure where it should be at. I just don't know where to go from here, a lot has been looked into already when we were trying to trace down why the O2 wasn't switching. Also when looking at the test papers it seemed to show that the high levels were at the higher speeds, seemed to do fine at lower speeds (we have the dyno tests here in Colorado). There are no more trouble codes so it's a toss up where to go from here. ECU wasn't the problem for the O2 not switching but since that was the AFM causing that I guesss I'm not sure if the ECU is completely ruled out now. Are there any suggestions at a starting point, should we pull the intake next, can't really just test the injectors and I don't wanna put them in unless I'm absolutely sure that's the problem as they are not cheap!

Just looking for any input on what to test next. It's been a real headache and I know my boyfriend is tired of dealing with it and so am I. I really need to get my baby to pass emissions just unfortunately previous owners hadn't been too nice to it we now have discovered. I may not have bought it had I known it had this big issue! Really hoped the AFM would have fixed it, but it only half way fixed the problem! ANY help would be much appreciated!!!!!

kinsey.clay

After talking with a master tech I worked with at a previous job, trying to rack his brain, one suggestion he gave me was the charcoal canister, especially if it had been running rich for a long time, which I'm pretty positive he had, poor truck didn't seem to be well maintained by some previous owners. I was just curious if anyone else has dealt with a problem with one? maybe a cheap fix? looks like they are expensive and hard to get but definately seems to be something that could be the cause of the running rich! Any input would help!

corich

Hi, Kinsey. You've done a lot of the stuff I'd look at. The big thing I don't see on your list is the Throttle Position Sensor (TPS) - maybe that's out of adjustment? In my experience, timing is pointless with a bad or misadjusted TPS. When I finally replaced mine and ran the timing, it was the first time my 22RE idled smoothly at the correct timing setting.

I suppose there's also a possibility that it's a vacuum line leak - check all those lines to see if you're sucking air anywhere. Or the thermostat. The cold start injector kicks up the fuel mixture when it's cold; if the truck never heats up, or thinks it never heats up, you might have a very rich mixture due to that.

Since we're both in Fort Collins, I'll throw in a plug for the guys at Integral Motors out on Link Lane - it's been a while since I've been in there, but I think they're pretty sharp and honest mechanics. If you end up stumped, you might try them.

Good luck to you!

corich

I should have put these in order of difficulty & expense :-) TPS adjustment is free but not easy; vacuum line fixes are almost free and simple; thermostats are cheap and simple; and a new TPS is probably more than a charcoal cannister, I'd guess.

Also, when you're looking at the thermostat, don't trust the temp gauge on your instrument panel, they sometimes read false on older trucks.

YoungFeller

You could always adjust the AFM on top of the airbox. That's the easiest way to change mixture that I know of. Be sure to mark the original position on the gear before you adjust it.

Instructions:
http://www.4x4wire.com/toyota/minutemods/afm/

kinsey.clay

UPDATE: Passed emissions with flying colors this morning!! You were right corich, my boyfriend adjusted the TPS then readjusted timing as well as the air/fuel screw wasn't in the right position either and he also did an induction clean cuz my intake is super gummed up, in the future i'll take it all the way off and clean it completely. The next step was gonna be to use the AFM off his toyota truck cuz the used one we put on looked like it had been tinkered with but didn't have to do that! Also put a used charcoal canister in it from a parts truck he has but mine didn't feel saturated so I don't think that was the case but we figured we would do it anyways. Has so much more power and runs like a champ. Fuel mileage is already looking better to as I could see it go down each little drive before where as it hasn't gone down yet now! Thanks for the input guys!

Corich, crazy to see a fellow fort collins person here, thanks for your input, my boyfriend owns Fry's Auto Care which is real near the one you were telling me about, not sure if you know of it but he's good there, he helped me out A LOT with this! Now it runs better then his toyota and my buddy's toyota

Thanks YoungFeller, if we had failed and my boyfriends AFM didn't work either that would have possibly been the next step but I really wanted to find the underlying cause of all of that. Now it should run like a champ and I shouldn't have to worry about any parts for a while!

corich

Woot! Glad you're in the clear. Sorry to suggest your boyfriend's competitor - I usually avoid suggesting mechanics unless it's specifically requested :-) I do most of my own work, but it's good to know about Fry's - I'm sure something will come along soon that I'll need help with.

kinsey.clay

haha it's all good! But ya he knows all about toyota's just about. he has an 84 truck that has been converted to fuel injected (from the donor truck of a few of my parts haha) and it's a fully built crawler. Pretty sweet! He's great with those things!