View Full Version : st185 swapping AFMs

06-19-2012, 02:24 AM
I was wondering if a newer AFM would help with some of the wierd problems I have with my car. At this point now that I bought another AFM that should have worked on my car that is my focus right now.

All I could think to do is put a tester, omega setting, on the old and the new AFM and compare. Here's what I found.

My 90 US 3SGTE AFM that works with my JDM swap and 92 ECU with tester on the used prongs they read from 1.65 to 1.95.

The supposed 91 US 3SGTE AFM that my car wont start with, the tester reads from 1.95 to 2.25.

Im guessing those readings are why my car wont start with the AFM I just got. I shoulda checked the part numbers for more info before coming here but didnt. My old one the sticker is hard to read its 2225?689?-74210 and the new one has no sticker but theres a number stamped in the same place 08K3459. Before submitting this I did a google search on these numbers and didnt find anything.

Any ideas or suggestions are appreciated. Thanks

06-19-2012, 08:35 PM
Your car should start no matter what. It doesnt use the AFM to start on a 185.

It starts, then switches to listen mode. You should be able to unplug your AFM and start the car. It will only run for a second or 2 but it SHOULD start.

06-20-2012, 02:29 AM
Well when cranking it would almost kick over but not quite enough to start. So how do I test the new one to see, as someone posted in the other thread to at least make sure it should work on an st185, where it should read 5-10 instead of 0-5 like the rest of the models? I tried most of the settings on my tester but didnt get any numbers like that. So if its right I will not try and return it, Id like to have 2 since I have 2 engines incase I ever rebuild my old one and swap it back.

edit: DOH, that was you Luni, and 5-0 instead of 0-5. So how do I test for that? I may have read that here long ago but that was before the site upgrade last year, wont find it now eh.


06-25-2012, 12:32 AM
Hook up the AFM to your wiring.
Turn the key to on.
Put the postive lead on VS and the negative lead on E1 or E2 [or any other good ground].
If the multimeter reads 4.9 or so, it goes 5 - 0 if it reads .1 or so it goes 0 - 5.

That's also a good way to check if the AFM is working ok, have someone move the flapper by hand and watch the reading. It should smoothly change.
You can also check while driving, make sure the reading changes smoothly.