kick7ca

This is a little technical, but some help would be appreciated.

The FSM test for the AFM on page 61 of FUEL & EMMISIONS CONTROL (sec 4)

It states the resistance between prong E2 and VS should be 200-600

My question: There are two E2 prongs, does the test apply to both E2s or just one.

I ask because my AFM satisfies the test using one of the E2s but not the other, so I don't know if I'm OK or not.

SureShot

On page 60 it shows the schematic.
One of the E2's closes with E1 when the flap starts to open to run the fuel pump.
The other is connected to the resistor.

HAILERS

Both E2 are one and the same.

Both are the third pin from the end. One is the third from the left and the other the third from the right. They should both read the same. If you look at the diagram (series four fsm, the Bb-1 diagram), they are both going to ground (BrB wire on a early 86/87) when they leave the afm.

They look redundant to me.

Sindregutt

i got the same resault as kick7ca.. i do get right value on the one E2 bot not the other.. bad AFM?

HAILERS

E2 is the third pin from the left and it's also the third pin from the right. Both of those pins are tied together inside the afm. They don't go to seperate circuits. Make sure your getting on the third pin from the left or the third pin from the right. With either pin you should get the same results.

Sindregutt

if i measure over the third pin from right and third from left i get 180ohhm

kick7ca

Mr. Hailers is correct, both E2 prongs are the same, I misread the diagram and measured second from left.

My results:
e2 - vs 243
e2 - vref 200
e2 - THA 1679
e1 - fc (flashing 1, then 0.00m) closed, 0.6 wide open
e2 - vs 241 closed, 51-54 wide open (bounces around a bit)

So I think it's OK, not sure what infinity looks like on a multimeter though...? e1-fc should be infinity closed and zero wide open, I'm pretty close I think.

WAYNE88N/A

There are some resistance readings that are funky on a known good AFM, I don't remember which pins, but I do remember scratching my head while I was checking it out of the car.

Something like when the door is slowly opened, the resistances jump up and down even though it should be a simple pot in there. Regardless, that's normal...

If you really want to check out the AFM's output, hook everything back up and test it out from the ECU with key on and then engine running. Voltage this time. Everything should be smooth and linear in this case as the car is accelerated. Plop the meter on the pax seat and go for a spin. Don't forget to watch the road

Sindregutt

well i didnt get the same result on both e2.. on mine i got 180ohm over them.
I DO got big problems with to much fuel, maybe this is the problem?

Sindregutt

i opened the AFM now, and i there is now way those E2 are the same. they are not connected directly to each other

HAILERS

Yes they are. E2 is the third pin over from the left and it's also the third pin from the right. They are tied together on the circuit board. The E2 on the left is also tied into the temp sensor thru the black wire (inside the AFM). You should be able to touch E2 on the left to E2 on the right and they should ohm out to each other with little to no resistance other than your meter leads. Done.

Don't let the picture in the book confuse you. Look carefully and you'll see that they are tied together along with the wiper on the pot and the temp sensor (THAa).

EDIT: And they are also tied together in the harness with a splice/crimp either a brown/black wire or on later cars a pure black wire.

Sindregutt

i cant see that their tied together on the circuitboard but i can se that E2 to the left is connected to the temp sens.. But if they are tied together in the harness it shouldnt be any problem