Scirocco16v

ok, I seareched a while in the posts but can't seem to find anything that addresses my situation... I keep failing emisions inspite replacing most of the emissions system. I appear to run rich (high Co & No).. new egr/tps/tuned/new exhaust/new cat/adj valves/ new injectors/ new vac lines/ etc etc

anywho I have good evidence the PO opened & monkeyed with the AFM (has been re-sealed). I opend it and the gear is kinda scratched up (tool marks on gear face and teeth) and there are no markings to show what the gear position might have been originally or anyway to know how many teeth it may have been moved or whatever.

do you think I should just trash it & get a new unit? I have researched the AFM-mod but dont see anything on how to reverse the mod if someone didnt do the easiest step there is, use a sharpie.

coryc85

I've never opened up my AFM, but I've read about it. Seems like you should be able to turn the wheel in the direction to relieve the spring tension on the flapper, which ought to allow more air into the engine. Might as well try that first since yours has already been tampered with. Worst case you end up buying one off a member on here. You didn't mention O2 sensor, but hopefully you have changed that.

Scirocco16v

yes I have:

02
Cat
exhaust pipe (manifold back)
EGR
Fuel filter
IACV
PCV
TPS
plugs/ & wires
Adj valves w/new adj screws (several times)
timing (several times)
fuel inj (all the fuel delivery sys is new from tank to injectors)

and much much more
https://docs.google.com/spreadsheet/...0E&usp=sharing

basicly I am thinking its AFM related I could be backing up the wrong tree though. just down to the two suspect, ts the clearly tampered AFM or I need to rebuild the head or something internal.
I qualify for a TN Emission wavier & can get tags, just stubborn and want it to run properly for all the work I have done.

irab88

iTrader: (4)

i'm guessing this is a 4cyl? anyway, i have a stock afm. $50 and it's yours, pm me if you want it.

scope103

High CO and high NOx don't usually go together. http://www.autoshop101.com/forms/h56.pdf .

Your high NO is most likely an EGR issue. I understand you've replaced a lot of parts, but there's a little more to it. In my engine, I had enough "gunk" in the plenum (upper intake manifold) that it nearly occluded the EGR input pipe -- had it gotten a little farther, I would be failing NOx even though the rest of the EGR system was all good. Try running through the EGR diagnostics in the manual.

"Rich" (the usual cause of high CO) should show up on your new O2 sensor. Test at the diagnostic connector to see that the signal is flipping back and forth around 8 times in 10 seconds. If you're up to it (you know you are!), read the learned trim to see if it's stuck at one end or the other.

In the end, this kind of problem really requires a 5-gas analyzer to track down; otherwise you're replacing a lot of good parts in the dark. Which means you need to find a shop that admires your stubbornness as much as the rest of us do.

Good luck!

Scirocco16v

yup 22RE

yea I guess I have to break down and find someone with a gas sniffer

Scirocco16v

if this sheds light on anything...

its a 22re

(New fuel sys)
1 test
HC=376 (initial running after 11yrs idle/tune/timing)
CO=11.92

2nd test (vac lines/tune/valves/timing/TPS/IACV/PCV)
HC=560
CO=9.96

3rd test (new EGR)
HC=361
CO=3.64

4th test (new cat/o2/exhaust manifold back)
HC=572
CO=7.58
-------------------------------------------
HC limit 220PPM
CO limit 1.20%

Gamefreakgc

Emissions control system and what each one does (FSM):

http://personal.utulsa.edu/~nathan-b...12systempu.pdf.

This should help narrow the potential causes. On second look, the issue might be your PAIR valve (reduces CO and NOx). Here's the diagnostics to make sure it is working right: http://personal.utulsa.edu/~nathan-b...20pulsedse.pdf

If you're looking to get a new AFM, there's a sweet little upgrade you can do that gets lots of power by using a AFM from a Cressida or Supra (allows roughly 30-40% more airflow and increases MPG and throttle response). Probably won't help with passing smog though.

https://www.yotatech.com/forums/f116...ap-3vze-60513/

Scirocco16v

ahh some how I have missed replaicing the pair, might as well, eveything else is new, lol.

sofar only found one shop in town who has a 5 gas rig.. and do they sound shady on the phone... and have even worse reviews online/BBB... & want to keep my truck "a few days"... oh hell no!

Scirocco16v

The PAIR passed its test.. though I didn't replace the associated hoses so I am doing that. Also going over the vac line layout one more time. EGR also tested normal

scope103

What are the units on these? Where are the NOx numbers?

In California, the units for HC are ppm, with a max (for an idle-only test) around 100 ppm. (Does 220ppm refer to HC?) CO is measured in a percentage, with a max of 0.6-1.0%. NOx is, again, measured in ppm with a max around 500ppm. (500ppm is 0.05%, so 1.20% sounds awfully high.)

If you're getting 300-500ppm HC, you're running so rich that you ought to see smoke. A cylinder missing can quickly drive HC that high.

Scirocco16v

I fixed my typos, suppose to be HC/CO.
It doesn't miss, runs nice, purrs like a kitten with a Timex. I found one of the VSV 's to be intermittent.. would test OK, then it might not test OK again, then test OK. Out of 8 checks, it failed half the time.. so just ordered all 3 VSV's from toyota. Prolly just get an AFM and be done with PO shinanigans

n16ht5

The earlier post is incorrect. You want to tighten the spring gear (more force on flapper) to go leaner. Try adjusting it 5 teeth tighter and see what happens. If you go to far it will run lean/hot, so don't spin it willy nilly

scope103

Did you ever test the O2 sensor to see if it is detecting your "rich" condition? The VAF only sets the mixture in open loop; after a few seconds the O2 sensor will warm up and take over. IF your VAF is screwed up, it is possible that you are running so rich that you've pegged the "learned trim" and the ECU can no longer adjust it far enough. But that's a) unlikely and b) easy to determine. And swapping the VAF is just throwing parts at it.

Your exhaust numbers say you are really, really rich. If you're not missing, and your O2 sensor is working, I'd suspect a leaking injector (but I know you've had yours serviced) or maybe a non-operable fuel pressure regulator (again, easy to test).

RSR

If you're going to be fiddling with your AFM meter, you might as well go ahead and get yourself a wideband 02 sensor and mount it in your cab. It will definitely help you to troubleshoot.

Scirocco16v

no, I`ve concluded its not worth my time fiddeling with a 24 year old part that has already been fiddled, cheap enough to replace it outright