Hi everyone,

This is my first post here in Club 4age, great forum by the way, i am from chile and did a swap on a Suzuki Samurai (4age 20v Silvertop Maf) and i have a little problem.

--> when my maf is conected the engine stalls, no codes. no check engine.
If i disconect the maf, my check engine accused me that AFM and IAT sensor have something, but runs great! perfect idle. 800 rpm.

Any ideas?

Greeting from Chile

Hola And welcome to club4AG.

If the engine cranks and fires up but stops as soon as you let go of the key,
check the ground wire from the AFM.

EDIT: Scratch that ^^^^ as the engine runs with the AFM disconnected. But
the engine (fuel pump) should not run when the AFM is disconnected, so you
must have the Circuit Opening Relay (COR) wired up in some way strange

The AFM and IAT generate a check light because you disconnected them. As
for running perfect... probably run better with a load signal from the AFM

Cheers... jondee86

jondee86 wrote:Hola And welcome to club4AG.

If the engine cranks and fires up but stops as soon as you let go of the key,
check the ground wire from the AFM.

EDIT: Scratch that ^^^^ as the engine runs with the AFM disconnected. But
the engine (fuel pump) should not run when the AFM is disconnected, so you
must have the Circuit Opening Relay (COR) wired up in some way strange

The AFM and IAT generate a check light because you disconnected them. As
for running perfect... probably run better with a load signal from the AFM

Cheers... jondee86

Hi Jondee86,

In this case and to simplify, the fuel pump is running directly from a fused BATT, the same as injector, ingniter, coil, ecu. etc....
so the pin 1 "FC" of the maf that ground the COR is not a failed point.

The harness was a scratch, i think that this was an automatic harness and adapted the plugs for the mecanical ecu, there are cuts an uniones in three parts of the maf harness, there are cuts on the igniter, and in two the ecu plugs. I did the work of compare it pin by pin with the silvertop diagram that i found here in the forum and there is continuity between sensor and actuators and ecu plugs. the earth and 12v are good.

the Maf i wire it my self....

Pin 1 "fc" wire it to nothing
pin 2 Ground
Pin 3 E2
pin 4 VC
pin 5 E2
Pin 6 VS
Pin 7 THA

That's a strange one alright !!! So long as you don't have E (chassis ground) and
E2 (ECU ground) hooked up together, I can't see any reason why having the AFM
connected would prevent the engine from running

Maybe someone else who is more familiar with 20V wiring can help ?

Cheers... jondee86

jondee86 wrote:That's a strange one alright !!! So long as you don't have E (chassis ground) and
E2 (ECU ground) hooked up together, I can't see any reason why having the AFM
connected would prevent the engine from running

Maybe someone else who is more familiar with 20V wiring can help ?

Cheers... jondee86

Why could be a reason for stalling if chasiss ground is conected to ecu ground??? y know that E2 (ecu ground) is a "pure earth"

Greetings

Wata GTE wrote:Why could be a reason for stalling if chasiss ground is conected to ecu ground???

To be honest, I don't know what the effect would be if E and E2 were joined.
But since Toyota decided they should be separate, there must be some good
reason. Since E2 is for sensor grounds, if I was guessing, maybe connecting
to E would upset the sensor readings ?

And basically, it was the only thing I could see that might stall the engine
when the AFM plug was connected. So I thought it would be worth checking.

Cheers... jondee86

If is runs fine with no AFM,
and wont with it plugged in
then most likely cause is faulty AFM.

Have struck that on a couple of 20V's now.

THREAD REVIVAL!!! any info on this? im having the same problem. its not the afm since i replaced it already. i did notice that the connector only using 5 wires instead of all 7 the last 2 are cut and not in use. engine runs for a second then dies with afm connected however i can keep it running if i accelerate, with it disconnected it idles perfect just a bit rich obviously. what can this be an solutions found?

From the Silvertop engine wiring diagram. (Don't remember where I found it but if you send me your email I will forward the PDF file to you)

AFM pins
1 FC
2 E
3 E22
4 VC
5 E2
6 VS
7 THA

hey thanks my email is alexfourtwenty@gmail.com these go straight to the ecu correct? if so i have 2 that are cut at the connector the last 2 are these needed? anyone know the funcion of these pins.?

Ok so I found out that I have to block the iscv in order to run the afm connected. Problem solved.

Probably why it was blocked before Means that your throttles and AFM have been messed
with to get idle air into the engine. Result will likely be that your idle will be low when the
engine is cold and rise as the engine warms up. Not really a big deal... easier to live with it
than to try and figure out why the ISCV got blocked in the first place. Drive safe... be happy

Cheers... jondee86