No CEL - MAF Tear Down - No Start - EB1 Faulty (Solved)

[george_tlc]

In your first pictures, I assume the +ve battery one was taken BEFORE you installed the washer/nut on the stud??

cheers,
george.

 

[1994LCNM]

In your first pictures, I assume the +ve battery one was taken BEFORE you installed the washer/nut on the stud??

cheers,
george.

View attachment 2874177

George, yes.

 

[1994LCNM]

PIP, to clarify, a few threads up is Jonhelds response, he is exactly right about that thread. What to do and what not to do, it's good medicine.

Like Sogafarm said, this part is NLA, proceed with caution.

To elaborate on your specific questions:

#1. The part of the connection, the one that attaches TO the MAF itself, the one with the TWO screws, the female port, that whole part is soldered in 3 locations so if you REMOVE it to access the inside, you will pull off the solder parts. Picture below.

#2. There's a plastic piece that typically gets clogged, maybe someone can chime in on this one. Picture below.

My ASSUMPTION, our assumption at this point is that the solder parts on the circuit board, the 3 points, fail.

#3. The circuit board, well kind of, it looks like a strong circuit board and you have to look at it under a scope to see if it's faulty.

Let me keep experimenting and I'll let you know more....

 

[FMC80]

The THA pin on my VAFM failed. Nothing else. I sent it in to get repaired and refurbished and the LC is running great now

 

[1994LCNM]

Which one is the THA?

 

[FMC80]

Which one is the THA?

It's the first pin on the right when looking at the VAFM port (female side). Ref this thread: **SOLVED** Codes 24 & 31 on 1994 FZJ - https://forum.ih8mud.com/threads/solved-codes-24-31-on-1994-fzj.1258070/

 

[george_tlc]

The black rectangles in the VAF internals pictures are resistors - deposited onto the backing (I presume it's a ceramic substrate). The actual resistance can be controlled by the 'goop mixture' and also the length/width/thickness of the rectangle.

As the wiper moves it sweeps to different spots that become electrically closer to different deposited resistors. Essentially it's a big variable resistor contraption that allows the ECU to determine where the vane is (that is being displaced/moved by the amount of airflow). Quite the contraption.

The newer non-moving part MAF is a more reliable sensor - unfortunately it's not a drop in replacement...

cheers,
george.

 

[1994LCNM]

George, you mention a non-moving configuration replacement... how?

 

[george_tlc]

George, you mention a non-moving configuration replacement... how?

Unfortunately it means moving to a 95+ with the MAF.... Sorry to get your hopes up.

cheers,
george.

 

[jonheld]

That discolored white plastic part is the intake air temperature sensor. It's a thermistor that feeds the ecu.

 

[ppc]

George, you mention a non-moving configuration replacement... how?

First thing you need to understand is the proper terminology. The ODB1 motors, 3FE in the 91-92 models or the 1FZ-FE in the 93-94 models use a VAF or AFM device to measure air entering the motor which is a mechanical flap that moves in proportion to the amount of air. The ODB2 1FZ-FE motor used in the 95-97 uses a MAF contains no moving parts but measures air by measuring how much a heated wire is cooled by the 'mass" of the air passing over the wire. Completely a different animal and the two are not interchangeable. There is a Russian company that developed a conversion device but it was expensive and don't think it is no longer available.

 

[bajaphile]

Are you sure that the security system isn't in some sort of immobilization function? I have seen systems which will default into a lockout mode if the battery was disconnected and reconnected. There should be a bypass switch located somewhere under the dash, hopefully. The solid red light vs blinking might be a clue... Just something I'd probably check before going further down any rabbit holes.

 

[jonheld]

The port installed or dealer installed security systems usually disable the starter logic, not the ECU and/or related components. IOW it would not effect the CEL.

I am not certain about this on the 93-94, but on the 3FE with a very similar AFM setup, removing the AFM connector does not effect the CEL unless there's a short internal to the AFM or it has been molested in some way, like removing the 2 Phillips screws that you're never supposed to remove and ripping the traces off the freaking board. In this case, with the AFM plugged in, the CEL will not illuminate, but unplugging the AFM will bring the CEL back on. That's how AFM problems can be quickly and easily diagnosed.

 

[FMC80]

Ya I'm buying a new one, found a source.

My friend owns a electrical engineering company. Just took it over there now. He already found the issue. Fixing it now.

For clarification and for the potential of others sourcing or fixing their VAFMs are you buying a used VAFM or fixing your original that you disassembled or both?

 

[1994LCNM]

Both here

 

[FMC80]

Both here

Can you provide more information? Your friend's going to fix your VAFM....then where are you sourcing the other one from? Any links? Prices? Info?

 

[Maynster]

It was a bad move to take your VAFM apart like that because you could have it refurbished.

Where are you sourcing a new VAFM from?

Do you know if a specific company that refurbishes these? Thanks.

 

[FMC80]

Do you know if a specific company that refurbishes these? Thanks.

I sent mine to Bavarian Restorations. It’s a more expensive option than the eBay dude but I believe it’s a better product and service.

 

[1994LCNM]

How much

 

[FMC80]

How much

I think the base cost was $320+SH for a full refurbishment.

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