Measuring resistance from 7 to 8 will provide difficult to interpret results. The best way to check the AFM slider is to put battery voltage across 9 to 6 (positive on 9, negative on 6), and then measure the voltage between 7 and 8 while you move the wiper around. This process is documented on page EE-13 of the 77 FSM)

The AFM is Dr. Bosch black magic and voodoo.

As for the dent in the wiper? I don't know what you mean. Can you circle what you're talking about on your pic?

Repairing a fuel injected car can be a pain in th A*se..😭

I would before doing anything to all the sensors in the system advice to FIRST do a compression test on the engine so you KNOW that the engine is mechanicaly in good order! Very important as with the electronics on these cars many things can go wrong. (Buy a good compression meter not expensive.)

Then also check every vacuum line and all the rubber hoses in the inlet system.. a small leak will throw the systems ECCS* (NOT A ECU, how many times do i have to say this... sorry.. anyhow..) the ECCS* get complete faulty readings when there is a air leak even a smallest one will ruin how the engine will run.

Also, Cleaning the electric contact with a good contactcleaner, like they use in boating is a good one look it up!

Cleaning contacts can be a temporary thing when you do it with a nail file, i would be very careful with those.. (At first the contacts will work but later on they will fail if they were silver or gold contacts.)

A lot of contacts have golden or silver contact points.. Golden contacts should really be cleaned with contact cleaner (or alcohol) as also silver contacts (But not necessarily on silver) @Yarb ) Copper contacts can be cleaned up with a small (nail) file without a problem.)

As a (ex) electronics guy i also know in audio there were a LOT of silver contacts and.. not many people i think know this:

Oxidized silver conducts electricity even better than silver itself! Really! So cleaning the silver-plated contacts is completely unnecessary and harmful, because you're making the silver layer even thinner.

Again, the conductivity of rusted (black!) silver is BETTER than of silver itself!

Further, as we all know gold does not rust so that is not a problem, clean it with alcohol and a cotton swab.

ECCS is what Nissan called the computer for the ZX's. The 280Z's used an ECU. He has a 1978 280Z.

At best you could correct people for adding the E. Electronic or electrical control unit.

I think he's talking about the bend in the wiper arm.

15 hours ago, Zed Head said:

I think he's talking about the bend in the wiper arm.

I'm almost... say 95% sure that bend in that contact arm is original.. It's there for adding just a little more stability to the contactarm.

Little update as I don’t have much time to work on the car. After connecting the AFM to a spare battery and testing the voltage on pin 7 I noticed very inconsistent voltage readings and a lot of gaps in the carbon track even though it doesn’t look damaged. And yes I know the AFM has a logarithmic scale with a range of 0 – 9 Volt, Its basically just a voltage divider and a potentiometer in one. Here is a picture I found together with the link and some other useful links (last one is for a Range Rover but it’s the same concept and same Bosch style AFM).

https://www.atlanticz.ca/zclub/techtips/afm/sizeupgrade/index.html

https://www.atlanticz.ca/zclub/techtips/afm/index.html

https://www.gomog.com/allmorgan/AFMadjust.html

After a bunch of searching I did fine more reference pictures of the Datsun 7 pin AFM’s and other Bosch AFM modules of the same type, that bend is 100% not supposed to be there. I did notice that if I press the copper part of the wiper hard against the carbon track I do get some sort of reading but so maybe somebody tried to “fix” the AFM by bending the wiper. Unfortunately the track has failed in its entirely and I can’t find anybody that can fix the circuit board. Enlarging the bolt slots and moving the wiper to a fresher part of the track also didn’t work.

This lead me deep into the Bosch AFM rabbit hole that is the world of Datsun / BMW / Porsche forums. I found an Australian forum post that mentions a slightly larger 90’s Toyota AFM being plug and play for his L28E 280Z(X?) with the part number F201 13 210 (197100-3420). This is also a 7 pin style AFM With the same internal (and pin) layout as the Datsun 7 pin AFM’s. When looking if I could find this AFM in Europe I actually found one at a local junkyard from a 1988-1992 2.2i GT Turbo 12V Ford (USA) Probe for €25,- so I ordered it immediately to try and test this theory (same AFM was also used on the Mazda 626 and 929, also found a part number from Standerd "MF9107"). The original post did mention you need to loosen the tension on the flap by 3 teeth as the flap is bigger than the Datsun AFM’s.

https://www.viczcar.com/forums/topic/6951-larger-afm-for-a-280zx

If this doesn’t work I will continue to look for an replacement Datsun AFM that doesn’t break the bank (I know, that’s a tough one). I might also look into making a custom plug and play MAF swap. I found a US based company called Split Second that makes MAF to AFM conversion modules and MAF conversion kits for BMW’s. They also have a 0-9 Volt module (PSC1-009) that might work with the stock Datsun ECU in theory.

https://splitsec.com/product/psc1-009-programmable-signal-calibrator-afm-to-maf-hv-output

https://splitsec.com/wp-content/uploads/technotes/TN2_AFM_to_MAF_Conversion.pdf

And yes I will post all my findings online as there isn’t much information to be found about AFM sensors and there alternatives. Also no I don’t want to carb swap my car, I want to stay EFI but don’t want to spend thousands yet to upgrade the entire EFI system.

If anybody has a 0-5 Volt (or 5-0 Volt) AFM module that needs a rebuild / modernization I found an interesting company in Switzerland called SyncroSweets that swaps the wiper potentiometer for a modern programable potentiometer that’s plug and play.

https://www.syncrosweets.ch/en/luftmengenmesser

Edited 44 minutes ago44 min by Mitchel0407
Added details about the Ford Probe AFM donor car