Now, having gone through this, Philbert should be taking in what has been posted and working with that.

And we'll all see what happens.

 

Guys - both of you -thanks so much for taking the time to weigh in - means a lot to me.

Co_94 - I will check out the VSV wiring to see if it's correct - pretty sure it is, as I took photos before/during to ensure the 2 wires were in the right spot. Also the VSV had a plastic cap on it that popped off during my whole job. I have the cap somewhere....if that cap is off, what effect would it have?

Regarding critters/disconnected hoses, I'll save you the 14 pages prior I replaced all hoses with OEM during my head job, and hot tanked the manifold and other metal components - it's CLEAN

I will try swapping in the old AFM to see if that makes a difference.

Here's an interesting update - I got off the train today from work and started it cold. It had the same symptoms: rough idle to start, stinky. So, before it warmed up I looked on the intake side of the AFM and the door was STUCK OPEN! I pushed it with my finger and it sprung closed again. Started it up again and seemed really normal for a bit. Couple revs while warming up, then got rough again and REALLY stinky (rich?). Threw a CEL - code 5 - O2 sensor/bad ECU. Shut it down and checked the AFM again - door was stuck open AGAIN! Set it back to normal and the CEL disappeared and it idled smooth.

So, seems like the AFM door likes to get stuck open when the gas is on a little bit.

From all these GREAT posts here, and the threads I've found this week online, I'm surmising that:
With the AFM stuck open and the engine cold at idle, the ECU thinks the throttle is open to match the AFM and dumps more fuel in, but because the throttle is closed, hardly any air is getting in and the engine runs really rich and stumbles due to hardly any air.

Does that sound right?

I bought this AFM from Kiyobrown and he said it had been modded by the previous owner - there is black silicone around the black box part. you guys mention the spring in the AFM is sensitive and I would imagine that....is there anything that can be done to "free up" the door in the AFM so it doesn't get stuck? The tension on the spring feels pretty good with my finger, so I wonder if there is something gumming up the inside that makes the door stick? I'll need to get it off and take a look - and search online more.

So, next steps are:

- Check out VSV wiring - relocate plastic cap and replace
- Swap in the OEM AFM to see if it makes a difference]
- Wait for more sage advice


PS: "Charcoal fluid" was my assumption that "starter fluid" meant "lighter fluid" for grilling.

I'm keeping the stock airbox parts in case SMOG has an issue with the setup

Again, huge thanks guys - really appreciate it!

 

If the 5m/7m AFM is getting stuck open by the airflow of a 22re, the tension on the air door was released "too much" even for those engines, and you got suckered into buying it.

 

Good catch SIR! Didn't even remeber to mention a sticking vane. Nothing to do now but figure out how and where it is hanging up and clean it lube it or grind it

You can work some WD40 into the lower pivot, have to becareful with the top pivot since it opens to the circuit board can't use anything that will damage the coatings or alter the conductivity. Could probably pop the cover off and work the nozzle under it just make sure you don't gunk up the board or leave a puddle, pretty sure it's all surface mount so everything to worry about is on the top of the board.

Wouldn't have any idea offhand where to start to return it to stock other than hope it was marked before altered. I guess in theory if you knew the original spring tension you could reset that to factory. Then it's a matter of tweaking the mixture screw.

Not sure on the VSV cap, pretty sure it had a bit of filter substance in it. Hit up Chef he's bound to have one

 

On another thread, a guy mentioned maybe my CSI was not working, and to remove the plug during warmup to see if it made a difference....

This morning I checked the AFM and the door was fine - not stuck open. I started it and got the same low, stumbling idle as before. Died a couple times before staying alive. In the first couple minutes of warmup, I disconnected the CSI plug - and plugged it in again - several times. Honestly really hard to tell if it made a difference because it was already stumbling so low. It wasn't a difference you'd notice like when you pull a spark plug wire or a coil on a modern car. Should it make a huge drop/kill the motor if CSI is working? I think I did it right but I really can't tell if it changed the motor's health when pulled/replaced/pulled....

Warmed up, it runs fine - just the cold start is still the issue.

I think the AFM vane is a separate issue that I maybe triggered during all this....still needs to be addressed though!

 

I don't think it should kill your operation just not having a cold start injector working even if it is not functioning at all... And unplugging it might tell you if it was working or not I guess... But I doubt it if your fuel pressure will be on full bore when cold... Even though you're idoling I don't think the injector resistor comes into play until you reach close loop. Anyway, I think probably the best way to tell the cold start injector is to start a call next time with the injector pulled out of the plenum, put it in a small jar, with the rag below or something, then have someone turn it over while you watch... It should definitely fire for several seconds until it gets started and then maybe a little longer if its freezing outside... Which is not a problem at the moment right? Hahaha. I had mentioned the IACV a couple times because it can cause funky wunky things, mainly because it is supposed to be allowing non metered air in from before the throttle body directly into the plenum. If its frozen shut but still reading, I guess it could cause a problem. Mine never did, all it did was fail to get the idle up above 750.

 

Yeah I need to try a few more things too:
- double check that I plugged Thermo time and thermo temp connectors correctly
- VSV wiring/cap
- Test original AFM
- Maybe test cold start, per Chef (and plug the hole it goes in too right??!)

Any idea how to test the IACV? Assume I need to remove it?

 

OK, I just looked back at my photos and I have the thermotime and thermosensor (brown and green) plugs correctly plugged in (green on drivers side, brown on pass side), so that's not the problem.

Check that off the list lol....

 

There are checks for both the heated (Page #7), and Wax type (Page #8-9)
http://www.autoshop101.com/forms/h21.pdf
For the heated type the quick test is to pinch the inlet hose, while cold you should have a large drop in RPM.
For the Wax type you have to cover the inlet on the throttle body.

You already know this system isn't working as intended so the quick tests aren't much help. You'll need to inspect the system(s).

It's worth noting the heated IACV uses the COR relay, incase you didn't read the full documentation, This may be an issue I noticed in the video you had to crank abit which maybe indicates the AFM not the COR is activating the fuel pump.

And for educational purposes. *cough mark*
All of these systems still flow air thru the VAFM, they only by-pass the throttle plate, so it's still "metered air". (Diagrams of this are on page 6 & 8, aswell as in the IACV specific document http://www.autoshop101.com/forms/h60.pdf )


The rich/lean adjustment on the AFM is slightly documented on page 2 of the first PDF. There is a stamped number next to the plugged screw, this tells the depth from the surface of the AFM casting to the mixture screw. So it's possible to return it to factory specs. Casting #30 = 13.0mm, #26 = 12.6mm , #24 = 12.4mm, these are listed in the chart on page 2 there are likely others I would imagine they would follow the same scheme (10mm + casting # in 1/10th mm).

 

Thanks CO, I'm getting TMI damage going on here from some of the other things I got going on.... And one of the things I meant buy non metered air earlier was just due to a vacuum leak.

Far as pinching of that hose in front for the IACV, I ended up replacing both of those with Toyota factory new from the dealer with my discount they were around $20. Good luck pinching it off otherwise because the thing is hard as a rock most often and can crumble into pieces inside/ on the inner layers of the hose which are even harder..... Which then takes those crumbled pieces of hardened and burnt up rubber right into the plenum and... Well you can guess where they go from there. Ted from engine builder actually warned me about doing this test. In the end I bit the bullet, call my buddy at the dealership and ordered me up one of the brand new ones... As I mentioned before it is still at 1200 rpm when fully cold and gradually drops to 750 exactly how it's supposed to. I found more people finding it useless to try and fix them then those that had success... But why not try right? They do get extremely gummy and corroded and full of electrolysis inside, and the spring-loaded arm is unable to pull back any longer... I also heard of them being stuck open.

Thanks again CO, for pointing out my misspeak... Oops

As far as the COR, I had lots of problems on warm restarts at one point before I replaced it because it was never disengaging to some degree and was becoming so hot that it nearly melted, and actually burned my finger to a blister when I touched it. It's likely that I caught it right at a point where it was probably about to catch on fire.... I'm probably a little off on this but as far as I understood, yes the air flow meter vein upon actuating will engage the fuel pump, but I know that my truck engages the cor before the first crank of the engine just after the STA position, yes I would imagine the second its running that is irrelevant. Once in awhile before I replace the core with the new one it would give me trouble starting but never any issues with hesitation or stumbling once it was running.

 

Mentioned before, the CSI should only operate during cranking during cold starts. It shouldn't do anything once the engine is running.

Not surprising since the CSI doesn't do anything when the engine is running.

And ... I'm confused now.

Did you find the air bypass screw I mentioned?
Did you adjust it so more air would go through the vane instead of bypass it? ... which would enrich the idle fuel mix...?

 

If the ambient temp is low enough that the valve hasn't already closed on its own.
Again, assuming the ambient temp isn't above its closed temp.

If by meaning it uses the COR you mean it also receives voltage when the fuel pump is running, I agree. But then if the fuel pump is running....

And I would harbor the guess that the stamped number you allude to references the intended installation for that AFM, and given the AFM is not installed on the intended vehicle- it is a 5/7 MGTE VAFM right?- that number isn't correct and the screw may need adjusted if the VAFM is installed on a 22re? ... no?

I thought I mentioned that already....

 

I didn't allude to anything I told him exactly where it was how it is marked and how to reset/check it since it's obviously been tampered with. (It's drilled out) It's a mixture ratio adjustment the stoichemtry doesn't change regardless of how many cylinders. Maybe you're thinking it needs so much by pass for so much cylinder volume? At any rate it can't hurt much to tweak it, specificly that the info is out there to reset it

The data sheet says "Heater current for the air valve is supplied by the circuit opening relay power contact, the same circuit which feeds the fuel pump". I'm not inclined to go and dig out the EWD and it's not exactly the clearest datasheet/schematic either but I'm pretty sure it's not just spliced into the FP wire there are likely some other components involved, it's easy enough to check however put the FP-B jumper in and meter the plug to the IACV heater coil.

Both Air valves don't fully close untill the 140-176f degree range. Even at 104f it flows somewhere between 5-9 m3/hr, or at ~68 12-16 m3/hr, on a moderate temp day of say 86f it flows ~10m3/hr which is about 1/3rd open.. (This is all in the data/tech sheet linked) Since I know he's not in the Sahara Pretty sure it should be open on a cold start.

Sorry Phil, here is some maybe more usefull information than the above clarifications
IACV inspections are covered in the docs I posted, and there should be some things in the FSM aswell. The ones I posted, aside from the visual inspections, can be done with it mounted.

I crossed off the cold start inspection, but I guess you could see if the injector it's self has malfunctioned and is leaking or stuck open. You don't actually need to run the engine to do that just unmount it unplug it from the control circuit and power up the fuel pump. If you want to run it with it unmounted you'll need/want to cover it's inlet.

I'm still to lazy to work out which VSV that is, but worst case it is the fuel pressure regulator if it is this just means the system is running at the slightly higher fuel pressure and thus the system will be slightly rich nothing the computer can't account/adjust for.

You'll want to add "vacuum leak check" to that list, like chef mentioned. It'll probably require a chemical test (starting fluid, propane gas) due to your AFM noise being so close. Usually if the IACV hose is loose(Or anything large for that matter) you can hear it sucking air, it has that nice sharp "turbine" sound.

Good luck, you'll find it if you keep at it!

 

I give up.

This is like trying to explain to someone that a 650CFM Holley with vacuum secondary will require adjustments when put on a Chrysler 2.2.

 

Thanks Guys - Didn't have much time to test anything since the last post - up at the in laws this weekend and drove the RAV4 up here.

Regarding the AFM and the 6 versus 4 cylinder application, from everything I've read about the 82 Supra AFM swap, there isn't any adjustment needed - it's plug n play 100%. But, this one appears to have been "modified" since the screw is visible, and there is black silicone around the "black box" portion of it. I will do some testing using the FSM when I'm home next week.

I read the autoshop link Co_94 provided - thanks! The test I was able to do briefly before I left was to pinch off the hose that goes from the intake to the IACV (this hose appears to go through the IAVC, out the back, and up in between the head and intake, and then into the intake manifold). So I pinched it closed while cold start (rough) idling...no change! So this tells me that the IACV is blocked or broken, because it should be letting air into the manifold when started cold, right?

Still need to do some vacuum leak testing and check out the VSV.

Won't have any updates for a few days since I'm 130 miles away.

Have a great weekend guys - back with more later.

 

Not a whole heck of a lot new - I was out of town this weekend, work's been nuts and I'm out of town tomorrow on business. Maybe I can get to it more on the weekend.

Drove it a bit and it's still got some major issues:
- cold start stumble and die it's had since I finished
- running really rich (can smell it, see some faint smoke here and there from the tailpipe, and mileage is terrible - about 14 MPG on this tank and I was getting 18 prior to the whole job
- Getting CEL once in a while when driving - sometimes it comes on and then disappears in a minute. when I test the codes, I get "5" which is that "bad ECU/rich or lean/bad O2" condition I read last week. My guess is it's the "rich" part since that's what I smell!
- The AFM door keeps getting stuck open - think this is telling my ECU that I'm sucking more air in than I really am at lower engine speeds, and thus dunping in more fuel
- Backfires sometimes but not often
- when I let off the gas on the highway, it REALLY reacts - like an engine brake - more forceful than ever before - could this be a dashpot issue? The dashpot was not making any contact with the throttle cam at ALL before - I adjusted to to 4Crawler's specs after this job
- acceleration on highway is rather lame - feels like it bogs down sometimes when I give it gas

What I HAVE been able to do in the limited time I've had:
- Check out IACV hose routing to ensure it's correct to FSM/parts diagram specs - it IS.
- Blow on the 2 large IACV air hoses when engine is warm (about 40 mins after an hour of driving - was over 100 degrees on the gauge); I barely got any air through when blowing from both ends toward the IACV - which seems to me to be what it should do (close up when warm so no extra air gets in?)

I have not done:
- vacuum leak test
- swap AFMs and test

More to come later- just been starved for time.

 

OK, I had a little time today to work on this and try to eliminate some variables.

It's been sitting a few days, so I tried blowing on the IACV hoses again to see if it were more "open" than earlier this week when I did that while warm. Same result - *barely* able to force any air through. This seemed strange to me, since, well, shouldn't it be open when cold to allow more air in, then close up as the coolant warms it up? Anyway, onto the next test.

My Whisky Tango intake setup for this test:


I swapped in the old AFM, started it cold, and it sounds great. No stumbling, no CEL, no rich smell. Runs really, really well.

Here is a video of the cold start with the original AFM hooked up:

http://s1354.photobucket.com/user/ph...a3ed1.mp4.html



The Supra AFM seems to me to be in pretty bad shape. The sensor in it does look really dirty. I sprayed MAF sensor cleaner on it and tried again but it still stumbles like crazy, even when warm. Here's what it looks like:



And here's the original, sitting on top of the Supra AFM (note the adapter plate on the Supra AFM for the cone filter):



I then did a vacuum test, spraying carb cleaner on vacuum connections and there was no jump in idle at all. I adjusted timing once more after it was warm, after adjusting the idle first. Sounds great.

Put the Supra AFM on and it sounds like crap, even when warm.

There is an adapter plate on the Supra AFM that allows for a cone filter to be added to it (like you see in the photos). However, that plate does not fit the original AFM unit, so I would need to use my original air box. That airbox won't fit on the pasenger side right now because of the mounting metal tabs it uses on the drivers side - I'd have to cut them off, then find a way to make it stay put. What I'm worried about is if I do that, then have to switch back to stock, I'm stuck with no mounting tabs

Anyone had luck finding a way to adapt a cone filter to the OEM 22RE 4Runner AFM? I don't really want to go back to stock locations as I like the battery swap location of things.

But, in short, it appears that the AFM was the thing causing all these issues - once removed from the equation and replaced with what was there before it, things got back to normal.

Is there any way to fix my Supra AFM - I know that sensor is supposed to be really sensitive.



So,

 

Well I read all this thread....I'm glad you have narrowed it down to your AFM, hopefully you find a solution to keep the supra AFM. It's been almost 2 weeks....Maybe you already have?

Anyways appreciate the pics and what not. My 87 is about to get a head gasket and timing chain job

 

Thanks for checking in, been meaning to update.

Swapped in the stock afm last weekend and I still have the cold start rough idle, but no more codes or running rich it appears. I now think that:
1) the supra afm is bad
2) I may have a throttle/tps/dashpot adjustment issue


Will try some new things and report back

Runs great when warm

 

Hmm... any movement on this? Last time I checked in you seemed to be moving along with a plan. Why not find an airbox from a part out? Modify one and save the other "in case".