AFV connector seems to be wonky. 1988 22re

[BozCrags]

If I wiggle the pin connector going into my AFV I can get the engine to stutter, trip an engine code, and even not start (err stay started really). I think the connector is a little wonky and id like to replace it before replacing the AFV, but I can't seem to find a part online.  Should I be heading to the junkyard?  

 

I found a troubleshooting guide for the AFV, measuring resistance between pins, but I was getting weird readings, so not sure if I was doing it right. I'm going to give it another go in a bit and try to see where the intermittent issue is coming from.  

[payaso del mar]

for stuff like plugs, you'll often find it cheaper if you look on CL for someone parting out a vehicle.....this is the sort of item that such folks rarely ever sell, it usually goes to the crusher with the hulk.  and this should be pretty generic between models....suspect all Toys from about that year used same connector.

[zero]

I have no idea what an "AFV" is.  That being said, many of the multi-pin connectors used on mid to late 80s Toyotas are also used on Kia Sportages up past year 2000 and are available new and cheap from many auto parts sellers.

[BozCrags]

41 minutes ago, jdemaris said:

I have no idea what an "AFV" is.  That being said, many of the multi-pin connectors used on mid to late 80s Toyotas are also used on Kia Sportages up past year 2000 and are available new and cheap from many auto parts sellers.

I believe it is the air flow valve. The sensor that sits on top of the air filter. In line with intake. 

 

Esit;'d. Sorry I meant air flow meter. My bad.  

Edited April 6, 2016 by BozCrags

[zero]

34 minutes ago, BozCrags said:

I believe it is the air flow valve. The sensor that sits on top of the air filter. In line with intake. 

Do you mean the "volume air flow meter?"

[payaso del mar]

they had to put something in there to restrict the intake airflow, else that fierce 22R would be snapping flywheel bolts like toothpicks...

{one of those vehicle bits, like distributors and carbs, that I won't miss.  I've toyed with the idea of replacing the ECM with a Megasquirt and converting the EFI to a speed-density system....I suspect eliminating the flapper valve would be worth 2-3 hp by itself, with no mpg hit....}

[zero]

What amazes me with my 22RE is the fuel injection system that fires a half charge of gasoline on every stroke.  That on an engine that only fires on every other stroke. So half a charge just sits there and waits for its turn to get used.  But it runs well so I guess that is all that counts.  My 1979 Datsun had the same type of "half charge" fuel injection.

[Maineah]

That's a very substantial plug and there should be no reason for it to fail unless it has been tampered with. The fuel pump control is inside of the AFM also, the vane has to open to keep the fuel pump running so any air leaks around the AFM could cause your problem that may explain the movement to keep it running may not be the plug but the AFM movement it's self. I would check into that first you can remove the plastic tube a stick your finger in there to open the vane with the key on the fuel pump should then run. Pretty common to fire the injector on exhaust it makes it a lot easier to control. As the exhaust valve is closing the intake is opening so it's no big deal.

[Maineah]

16 hours ago, payaso del mar said:

they had to put something in there to restrict the intake airflow, else that fierce 22R would be snapping flywheel bolts like toothpicks...

{one of those vehicle bits, like distributors and carbs, that I won't miss.  I've toyed with the idea of replacing the ECM with a Megasquirt and converting the EFI to a speed-density system....I suspect eliminating the flapper valve would be worth 2-3 hp by itself, with no mpg hit....}

The AFM only meters the air flow the throttle body controls the intake, The flow through the air filter, throttle body, AFM and piping is far greater that the engine demand.

[payaso del mar]

Maineah---yeah, I understand that.  you are 100% right that the ultimate flow rate of all that stuff is probably higher than the CFM the engine flows at redline. 

however, this doesn't address the effect any flow restrictions have on the engine's efficiency and drivability, especially at part throttle where most engines spend most of their time.  the issue isn't just ultimate air mass flow capability; flow velocity is also critical to throttle response.  this is one reason that 2ish liter engines with huge Webers and 2.5" exhaust header primaries don't respond worth a darn at low rpms and throttle settings:  low flow velocity.  There's another reason that most all manufacturers are moving to reduce such flow restrictions, and it's called CAFE.  getting rid of VAF flapper valves was a good first step, but you notice that not many new vehicles even use a hot-wire MAF sensor any more.  All I was tossing out as an idea is what the vehicle manufacturers are now doing.....modern engine management can make even a dinosaur of an engine (3R-Z, Jeep 4.0, ???) function pretty well.

these same two reasons....throttle response and CAFE....are much of why the injection is now invariably sequentially fired instead of being the old every-other-stroke batch-fire system JD mentioned.....as he says, it works OK.  Remember that, ultimately, a controlled drip of gasoline into an intake manifold would allow an engine to marginally run (this is how old motorcycles used to do cold start enrichment, dribbling a little extra fuel into the manifold through a "tickler") , but the better you can mix it with the air and the finer you can atomize it, the happier it burns.  for this reason, just dumping it into the manifold on the revolution before doesn't get the maximum efficiency out of every gram of fuel, nor does it give optimum throttle response compared to firing the atomized shot of fuel right into the ingoing "gulp" of air it is going to burn with, as the air is going into the combustion chamber.  the current cutting edge on this front is direct injection right into the combustion chamber (instead of into the intake tract just shy of the intake valve):  huge increases in efficiency and reduction of emissions, at the expense of more engine noise and much more expensive injectors (gotta stand up to 1200ish degrees F and sevl thousand psi combustion pressure, as opposed to partial vacuum and sub-200 degree air in the intake tract)