Mitchel0407

Thanks for the mention! I just updated the thread as I’m diving head first into the AFM rabbit hole. Some tips I picked up on my journey: - Clean all the electrical connectors to the sensors (also the bullet connectors in the harness). - Measure the resistance to the AFM air temperature sensor and the coolant temperature sensor to make sure there within spec (coolant sensor is one of the most important sensors in the EFI system!). - Buy or borrow a timing gun and make sure the timing is set correctly. - Verify you are getting enough spark (right type and gap spark plugs, distributer contacts in good condition, ignition coil resistance within spec (0,8 to 1 Ohm)). - Install a wideband O2 sensor with gauge (cheap Chinese one is good enough for now) or if you don’t have a bung in you exhaust buy an exhaust sniffer so you can measure you AFR (Air Fuel Ratio). Idle should be around 14,7 and wide open throttle 12,5 I believe. - Try and see (while monitoring the AFR) if only you idle or the entire rpm range is out of spec. If it’s only idle maybe try and play with the idle air screw on the AFM to get the idle AFR back into spec. And If nothing work only then take the AFM off the car and start testing the resistance values. The number 7 pin is hard to measure the resistance so you must hook it up to a battery (9 or 12V) to test the output voltage on the number 7 pin. If you determine that that is your issue then welcome to my world! As you are based in the US maybe an AFM rebuilt offered by jdm-car-parts or Z-store is an option for you. Unfortunately I am not so it would cost an fortune to do so for me in postage and import tariffs.

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

That's a nice color and wheel combination u got there.....

Yeah no turns out I'm just an idiot who set his meter to the wrong range. Turns out my temperature sensor is just fine with a reading of 2540 Ohm at 20°C (68°F). While I had the meter in hand I decided to take the AFM off the car and measure that as well. Long story shot I believe the carbon trace or the wiper inside the AFM is defective. When measuring between pin 7 and 8 I got very inconsistent and high values. When measuring between pin 8 and the silver parts of the the circuit bord the values ranged from 180 to 10 ohm on a logarithmic scale. I did notice the wiper has a dent in it? I don't think that should be there as I believe I can see signs that it has been dragging on the trace. No clue how that could happen. Just in case can someone confirm if that dent should be there? I don't think it does as I can't see it on any reference pictures. I will try and bent the wiper back into shape tomorrow and see if that helps.

Don’t just go to the first body shop you can find. Most of the insurance painters and repair shops don’t really care as long as they get paid which leads to orange peel and miss matched paint. Like Patcon sad, ask the local automotive paint supply stores or classic car dealers (doesn’t matter which make). Had a big scratch on the passenger door of my 2008 VW Polo thanks to the previous owner (my sister’s husband). I found a local paint shop that was recommended by the dent removal guy at work (worked at the BMW motorcycle dealer for a while as a part time job). He resprayed the entire right side of the car otherwise you would see the difference in color (light grey car). All in all it cost me €600 cash and the result was perfect, you could not see the difference at all. My ’77 280z will also need some rust repair and painting within the coming years. I’ll probably take it to that guy as het specializes in high end BMW and Audi’s and rare classic BMW’s. He had a BMW 2002, E30 M3 EVO 2 and a first gen 6 series in the shop at that time for full body restauration. That and he accepts cash jobs which save me some money.

Pretty late to the party but both Z’s in the video where (I believe) owned by the same guy at that time. He unfortunately sold the orange one and repainted the gray Z to yellow but ultimately sold that car as well for a BMW E92 M3. He now goes by @Dutch_e92m3 on Instagram.

Yeah here in the Netherlands not so much. You can get into serious trouble if you’re caught by the police or “Handhaving” (translated to peacekeepers, basically police without weapon rights and with a main goal to be assholes and write tickets) or get into an accident (voids all insurance and you will be 100% liable for everything). That sad I did take it around the block when I got it home and even though the car runs rich as hell it still drive pretty good. Had some time to look at the car yesterday evening and I might have found the problem. When measuring the resistance values of the AFM and temperature sensors I noticed the coolant temperature sensor (2 pin) suddenly dropping down to only 2 ohm! So I guess that the temperature sensor is bad after all. I hope I can find a replacement as they can be hard to get over here and after that verify the AFM is set correctly.

The car is as far as I have seen completely stock with the exception of aftermarket exhaust headers (explains the O2 sensor bung) and a aftermarket cold air intake filter. The crank angle sensor sits on a (I believe) homemade bracket and isn’t connected to anything. The Electrical harness (both car and engine) also aren’t modified so that lead me to the conclusion that the might have been used to “tune” the stock system. I am happy with the aftermarket exhaust headers as they sound good and I can watch the AFR via the O2 sensor and the temporary AFR gauge. I would like to monitor the AFR when driving but unfortunately the car doesn’t have an valid inspection so I can’t drive it on the road. And guess the reason it didn’t pas inspection…. So now I can only try and retune the car while stationary on my driveway, which should work fine enough for now. I did check and adjusted the TPS as the two prongs were a bit too close to each other and there was no middle ground between idle and wot positions. I set the timing to 16 btdc and the idle to 800rpm btw. I also blocked off the fuel supply to the cold start valve to eliminate that as a possible problem (don’t really need it anyway in my case). Only possible options I can think of now is to measure and check the electrical sensors (yes I read the EFI bible) and clean the inside of the AFM unit. Might also clean the injectors while I’m at it.

I have already ordered some new vacuum lines just in case as some of them seem a bit hard and if one cracks it can cause a lot of problems. But as far as I’ve seen my vacuum should be fine. My AFM unit did seem pretty dirty on the inside so I was thinking of cleaning it in a ultrasonic cleaner with an electronics friendly cleaner. Also somebody did have the AFM open at some point in time but I don’t know if they messed with the gears inside. I do have a pretty good understanding of the 280z EFI system and the inner workings of the components so I’m not afraid to touch the AFM unit but I would still like to ask for some tips and directions to look at. All in all the entire engine needed a tune up as many contacts where slightly corroded or out of spec and I suspect the car was "tuned" at some point as it has an aftermarket O2 and crank angle sensor, neither one hooked up to anything. The car runs way better now but it’s still running too rich. My vacuum lines should come in this week and I’ll do some more component testing and cleaning before I start messing with the AFM itself.

Hello everyone, maybe somebody can help me? My 1977 280z is running rich at idle and the idle mixture on the AFM doesn't seem to help. I spend the last few days cleaning the electrical connections and timing the ignition again as it was out of spec. The car runs way better but the AFR gauge I temporarily installed still shows 11,5 at idle. I'd like to bring that down (or up depending how you look at it) to 14,7 as the car stinks of gasoline. The previous owner mentioned that the car running rich was the reason it didn't pass inspection (auction company didn't mention it had no valid inspection on it, APK over here in the Netherlands). After cleaning all the connections and checking the timing I tried messing with the idle air mixture screw but that didn't help. When turning clockwise a bunch the car did start to run richer at some point but when turning anti clockwise it didn't get past 11,5 AFR. Can anybody help me diagnose the problem? I would really like to drive the car on the road before the winter stop (oldtimer insurance). Also still waiting on some parts from Zservices EU but some are on backorder. In my quest to make the car run as it should I did notice the ignition coil is a 1,5 ohm unit with a total resistance of 2 ohm with the external resistor. I believe it needs to be closer to 1 ohm total so I'll probably replace the coil with a 0,5 Ohm one. Can somebody confirm this?

I have a set of aftermarket wheels on my 1977 280z with 195/70R14 front and 225/60R14 rear and I really don’t advise going over 195 front as the steering becomes very difficult. I do have the original wheels (same as you have) but I don’t know what the tire size is on those.

If they fall down can you still get them back up into position? I saw a guy on youtube that unbolted the hinge on the door side first and after the got the car side with a wrench and swivel sockets. I might try to go that route as the car doesn’t fit in the garage (and still work on it, only 2m wide for the first 4 meters). I do have a lager carport where I park the car under to work on it so the car is still dry. That does mean I’ll have to cover the car if I take the doors off but I had to do that anyway.

No as far as I know with the introduction of fuel injection they switched from inside to outside as they where in the way of the ECU and fuse panel.

Bit late to the party but I believe my 280z came with the same or allmost the same wheels. Don’t know if they are modified as I haven’t taken the wheels off yet but I must say they look pretty good under my silver Z. Attached is one of the pictures from the auction I bought the car from. The seller also included the original set of wheels but I prefer these. Tire size is 225/60R14 in the rear and 195/70R14 in the front.

Maybe a bit late to the party but I’ll be using this thread to rebuild my 1977 280z door hinges as the passenger side in particular sages so much that the door won’t even close anymore. Any tips on removing and installing the doors on a 280z? The tricky bit is that they are bolted from the outside and I don’t want to remove the entire front end.