I have the manuals and am diligently looking through them, but having trouble finding anything that tells me what we need to know. On page FI-46 and 47 of the 5mge Engine Repair Manual, it talks about the AFM. It gives some Ohm readings when testing the resistance of the AFM, but I don't see anything that mentions volts. Help!
TSRM 1983, fi -73 measuring plate fully closed 4-5 volts,measuring plate fully open 0.02- 0.08. At idle 2-4 volts.At 3000 rpm 0.3-1.0 volts.Thats at Vs(afm)-E2(ground) all year AFM'S must have the same volt output.
Check Vs Voltage:
Connect voltmeter to checker and depress voltage check switch.
STD: 0.5-2.0V (Measuring plate fully closed, IG S/W ON)
5.0-8.0V (Measuring plate fully open, IG S/W ON)
2.5-5.5V (Engine idling, IG S/W ON)
I don't know what that means....help again.[/quote]
This means the output (pot curve) is backwards from the output of the 83 and up AFM.
Actually a MAF conversion should be easier using an ECU designed to read this output. Since this is the same output (low volts at low flow, high volts at high flow) that a standard MAF uses the only thing S/S has to do is setup the tunability, and leave out the signal inverter software.
Bob are you seeing this? What Jamie says makes sense based on what the TSRM says. I am not sure What Dave was looking at, but I quoted right from the book. Can you check with SS to see what they have to say about this? Maybe my kit would be cheaper... :lol:
Hmm...Dave A is still saying that the 82 is the same... but reading that, along with what Jamie said makes sense to me...
They do have a kit like that... The price is listed the same as the price on the kit the rest of us need, so I am assuming (and I hope this assumption doesn't bite me on the ass) that it shouldn't be a problem...
One more tihng I see is that you'll not be able to use our maps for your car, as the signal output will be different... or at least I think. IF I can ever get a hold of someone there, I'll call you direct on the phone Chad. Whats a good time to call ya?
Arrrrrgh! I just typed about 20 lines of a reply to this topic and got "invalid session" when I clicked the submit key. What did I do wrong? This is frustrating since now my reply has disappeared into thin air. See pages FI-46 and FI-47 in the 82 TSRM.
Dave, your using AOL's Browser aren't ya? PHP codes (thats what this board is based on) and AOL don't like one another and do not get along. Minimize AOL and use this board thru I.E. or Nutscrape Navigator.
The schematic for the 82 AFM on page FI-46 in the 82 TSRM shows that the 82 AFM potentiometer terminals Vs and E2 are wired in reverse of the 83-86 AFM's. This would indicate that the 82 AFM does indeed have a low to high voltage curve of approx. 0-8 VDC as opposed to 5-0 VDC for the 83-86 AFM's. I/we need the AFM voltage check page from the 82 TSRM to help with what connects to what and why on the 82 AFM and ECU.
I suspect that the increased output voltage that appears to top out at 8 volts is due to the additional connection labeled Vb on the 82 AFM. See if you can find anything in your 82 TSRM that refers specifically to the Vb terminal and what the DC voltage should be on that terminal with the ignition switch On. The maximum output voltage of 8 volts DC may or may not cause a problem with the Split Second signal converter, but the techs. at Split Second will need the specs. in order to provide the proper box for the 82.
Chad, Split Second shouldn't have any problem putting together a MAF sensor conversion box for your 82. All they really need to know is what the voltage output curve is on the AFM Vs terminal. You can easily check this against the specs. in the TSRM by connecting a DC voltmeter to the Vs terminal and moving the flap through it's complete range by hand with the ignition switch On. As long as you have a good ballpark idea of what the DC voltage is on Vs with the flap closed and fully open, the techs. at Split Second should be able to provide a box that will work just fine on the 82. In fact, building a box for the 82 should be a lot simpler since no voltage signal reversal is required like for the other AFM's. All SS has to do is leave out the op-amp that forms the DC voltage differential amplifier and retain the programmable microcontroller. That is of course if the SS black box is designed anything like my own. :wink: The only possible headache that "might" be a problem is if the SS box only allows for a max. input voltage of no greater than 5 volts DC. Maybe you or Supra-Bob could consult with Marc at SS about this? Also, the 82 AFM flap opens fully at a higher RPM than the others due to the spring tensioned stop. This just means that the max. DC output voltage at Vs would occur at a higher RPM than on the later models, which really shouldn't pose any problem with the conversion box design
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