johnny haywire

I'd love to see some photos if you have any, sounds like a cool addition to the car.

I think the horn color is great, especially with the valve cover. It gives you license for more subtle red. Calipers as well, maybe?

Ha! Don't be too hard on yourself, flash makes everything look a lot more severe. I bet you can hardly see anything on the door panel in normal light. Good call on going back to the stock shifter. While I like the idea of a shorter throw, the stock one in my '78 really isn't too bad (I'm sure Datsun did their homework), especially with fresh bushings. Case in point - driving in Chicago (or any metro area) in a Z car can be scary, you can't see $%^& around blind corners due (as we all know) to the long nose. I had to take a semi-blind turn this afternoon, and what do you know, another car coming up quick on my tail, had to put the pedal down a bit and I was sort of surprised when I got rubber in 2nd. Though I suppose the benefit of a short throw is more from 2nd to 3rd, etc. Man, I'm really dying to get a carburated car after seeing your intake set-up. Thanks again for the excellent documentation of your swap!

Excellent point. I thought I remembered reading about that in the '78 FSM. It makes perfect sense...vestigial tails. I'll just be happy enough with a complete and working AFM, regardless of year. The difference in performance since I calibrated mine has been noticeable, so I imagine with the counterweight, it'll probably be even better. Thanks again for all the insight on this, guys. If we ever meet, I'll be buying the rounds!

Duplicate post - sorry!

Many thanks for both of your replies - this is extremely helpful. I suspected it was the wrong year AFM due to the cut-off switch being there and the lack of female connectors on my harness plug (no wires or female connectors in the plug for 39 and 36). Thanks also for the info on the counterweight - I will be much more educated when I go and check these AFMs out. I plan to test them all before pulling the trigger. Also great to know that any late '74-'78 AFM will work fine. I am going to shoot for a '78 version if possible, but I'll be happy enough to just get an unmolested one (if possible). One other question - is the counterweight removable or has mine been broken off? I got lucky finding the local guy with the AFMs - I just posted a WTB ad on the local Craigslist and got a response a day later. We still haven't met, though, so...fingers crossed, breath not held.

Amigos, The AFM on my '78 has been messed with, the previous owner had it leaned out considerably (and it still ran quite rich, probably richer now that I recalibrated it - decreasing the tension about 10 teeth) and upon inspection, it appears that the counterweight has been removed from the wiper. Luckily, I have found someone locally who said he has 5 AFMs, 3 working, 2 for cores, and I think I'm going to check them out this weekend but I have a few questions as the only ones I've ever seen the internals on are mine and the ones that Blue posted in his adjustment and calibration pages on the Atlantic Z site (many thanks, Blue, you saved my arse!). The first question - do '78 AFMs have pins for 39 and 36 (the fuel cut-off)? The AFM I currently have (A31-601 000) does have the fuel cut-off contacts on the board and has pins 39 and 36, while my harness connector does not have anything there for pins 39 and 36. And my other question - my '78 AFM is supposed to have a counterweight on the wiper mechanism, right? Here's how it currently looks: Many thanks in advance!

It definitely runs better since I recalibrated it according to the Atlantic Z method (Blue?), but the counterweight must have some effect on its operation, so...not knowing how it really should act is going to get the best of me. The hunt for another AFM is on. Anyone have any spares for sale?

Thanks for the tips and the photo, Grant, much appreciated. Do you recall how the counterweight was affixed to the mechanism? I'm going to look at the car today and see if I can get the numbers from the circuit board to make sure that my AFM is even correct for the car. The cover numbers indicate so, but... I'll ring a few wrecking yards and see what I can come up with.

Ha-ha, yeah, that last owner (or maybe the last two) were butchers. When I got the car, there were mismatched spark plugs, no battery hold-down, the fuel rail and injector lines were done up with hose that had "NOT FOR FUEL INJECTION" clearly printed on it, and the battery in the car (on the list to replace) is a tiny little thing. Luckily, after owning the car for a year, I think I've pretty much found all the bits that were messed with, and there aren't too many, but enough to keep me busy... Do you know how the counterweight is affixed? If it's a bolt-on piece, I may try placing a want ad in the classifieds, maybe someone has a junker/parts AFM kicking around. The unit itself seems to be working, the resistance tested out fine, and the voltage output seemed to decrease smoothly as I moved the flap with the tester connected, so...hopefully it's salvageable. Thanks again for all your help!

I was curious as to why mine didn't have one and all the Atlantic Z photos did. I was hoping that they changed it from '76 to '78 and maybe that was the reason? But perhaps it's just plain removed. Always something, eh? Here's a shot of the cover - it appears to be for a 280Z, I cross-checked the numbers on the MSA site. What year cars did the AFMs you've had come out of? Thanks for the input on the injectors. I changed the plugs recently and they all seem to be pretty uniform, so I'm guessing they are alright. I do plan on putting an inline fuel pressure gauge to make sure I'm not overloading them.

Excellent point, Zed Head. I snapped a couple shots today so I could read the numbers. Photos below. Cylinders 1, 3, 4, 5, 6 have green injectors with: 0 280 150 116 Cylinder 2 has a tan/brownish injector with: A46-000001 I also noticed that my AFM doesn't have a counter weight on the side opposite of the wiper. Is that correct for a '78 280z w/manual?

Here is the latest update. After calibrating the AFM according to the Altantic Z tech tips (and adjusting the spring setting to be looser to achieve this), I reinstalled the AFM and fired her up. Since it was about 90 degrees in the garage, none of the high idle, it just settled quickly at around 1000 RPM. I then noticed that with the decreased spring tension on the AFM flap, the car returns to idle as it should after a rev, and didn't change much while finger-testing the AFM. I decided to try and get the idle down to 800 (as indicated by the FSM) and had to bottom out the idle screw on the throttle body to get there. And then it died on me. So I backed it off and then turned in the idle screw on the AFM a good bit and then tried again. It seemed to get the idle down, but initial throttle response was boggy, so I set her back up as she was (with decent response) at around 1000 RPM for the idle. I tried the finger test at 3000 RPM to see if it sounded any better (clockwise was the same, counter-clockwise lowered the engine speed), but couldn't tell. I was alone, so I didn't have anyone to sniff around near the exhaust to see if it ran leaner if I closed the flap a bit. At any rate, it's much more "growly" now and the response is nice, and the engine settles back to idle quickly now (as a result of calibrating the AFM?), but still running very rich. Wade - I checked near the pedal and the linkage under the dash and there is no interference, everything seems to be working fine there. I'm not really sure where to go next. The previous owner replaced the connectors for the injectors and I believe had the injectors cleaned, but I can't really be sure of what was done there. The connections are soldered, so at least he did that. One thing I did notice while just having a beer and looking around the engine compartment is that the head is a different color than the block, it's silver and the paint is pretty clean, whereas the block is blue and is pretty crusty-looking. So, I'm guessing that was redone at some point in the past. Ah, well. I'm stumped for now on this rich situation. Next phase is to replace all the connectors with the new kit I got from Kurk on HybridZ. Most of mine are in pretty bad shape as it is...

Excellent thread, sir, thanks again for posting this. I have truly enjoyed following your progress, and felt your pain after what you just went through with the tranny. I had no idea that could happen in transit. Duly noted... One side note with regard to using the original (brass) radiator vs. a new aluminum one. When I was driving my newly purchased 280Z home to Chicago from LA last year, the original (I believe) radiator started leaking pretty badly just after I crossed the Kansas border, basically a steady stream pouring out of the driver's side toward my AFM. It was 3:30pm on a Tuesday and the nearest radiator shop was 40 miles back down the highway in the wrong direction. But with half a shaker of ground black pepper (seriously, the radiator guy suggested this and it held), I was able to make it back there with no more leaking. And the only reason it could be repaired was because it was an older brass radiator. The guy who fixed it (Alex's Radiator in Goodland, KS) was pretty impressed once he filled the hole and 6 cracks, and said it held 80psi now and should cool even better. At any rate, the old ones are repairable, at least. And I've had no cooling issues since. Didn't have any before that, either, but the car had sat for so long, a driveway coolant change before I set out just wasn't able to get all the funk out. Needed a pressure blast... Looking forward to your upcoming posts!!

Good point. I'll have a look at that tonight, Wade. I have inspected the engine bay linkage and throttle butterfly and all seems well in there, but I haven't really studied the pedal area. The idle doesn't seem to be high so much as it just doesn't like to settle where it should be. It does on occasion, or if I let the clutch out a bit to put the engine under load, but at stop lights, etc., it generally tends to stay a few hundred RPMs higher than it should and then drops to normal as soon as I start letting the clutch out. And the exhaust fumes are very rich, at idle and while cruising.

I had a bit of time to do the Atlantic Z calibration (with the beer can and string) and, oddly enough, it indicated that my spring was too tight (indicating that less fuel is being sent). Hmm. That kind of stumps me, because the Z runs riiiiiich. At any rate, I adjusted the spring tension to 4.9 and 9.8 fl. oz of water respectively for half open and fully open. Next step is to install it and try the finger test while she's running. I think I also need to test my altitude compensator (it's a California car). I suppose that could be stuck on? I'll keep you guys posted!

Okay, well, another round of beers for you guys. And thank you for the reality check! The AFM will not be visiting MSA. Not sure why I was so apprehensive, but eventually I was able to pull the cover off after much trimming back of silicone, careful not to crack it (I used an old chisel and a pretty massive flat-blade screwdriver to get it off). It was sloppy as hell, silicone inside the chamber and everything, and the cover does have some chips (that can be refilled). The spring has definitely been messed with, but I can't really tell which way (I'm assuming toward the richer end of the spectrum). I'm going to do the Atlantic Z method of recalibrating and then take it from there, since any tell-tale glue-blob signs of original placement are long gone. Once again, many thanks to Zed Head and Fastwoman for the help and advice! I really appreciate the time you have taken with me on this, it means a lot. I hope I can repay the favor one of these days. Updates to come once I get back from Cleveland. Cheers!

I did do the testing - the resistance on both sets of pins came out fine, just a little bit over 180 and 100, respectively. I also jumped 12V to it and checked the voltage as I moved the vane open. It went from 6.37 to 0 (when fully opened). Does the voltage measurement sound like it's within spec? I guess I was just concerned about screwing up the cover even worse than it is and recalibrating it. I don't necessarily think the AFM has failed so much as it needs to be recalibrated (I'm thinking the previous butcher cheated it to run richer) and the cover may crack in getting it off, but I am really glad you guys are talking me out of sending it in! I spent a few more minutes trimming off excess silicone, but the cover isn't budging so far. I've dug up my x-acto knife kit and will try some more trimming this evening. I'll post some pics once the cover is off before attempting recalibration. Might not be for a few days, though, as I'll be away from the car for a few days. Thanks again!!

The cover seems like it is sealing, though it is caulked on there pretty well, maybe too well. The edges seem to want to crack off rather than give after cutting the silicone and trying to remove it. I think the silicone was used very excessively. I'm very tempted to let MSA deal with this end of things and then I'll clean up the cam/lash pads while she is disabled during the shipping process. I need to re-mark my timing mark as well. So...I've got a few things to do while my AFM crosses the country. I talked to MSA and sent pictures and they said that the core seems acceptable. So, it's all packed up and will go in the mail today unless you talk me out of it I am very excited to see how the car runs with all the sensors working. It will probably take about a week, but I'll definitely keep you posted on the progress!

Okay, another update, had a chance to pull the AFM and clean it out. The "cracks" on my boot were actually the part numbers, and both boots are good, but...someone has been into the AFM. Damn! Clean as a whistle inside, flap moves freely but slams shut, so, the "return to zero" shock absorber spring is not set correctly. To make matters worse, the edges of the black cover is in pretty rough shape and has been siliconed on pretty tightly. I've read through the Atlantic Z pages on the AFM adjustment and calibration and that pretty much looks like what's in store for me. I've decided to leave it alone for today and try to carefully remove the black cover tomorrow. I can see little parts on the edges are missing as it is, so going to try and remove it as gently as possible. I wonder if MSA would still accept this one as a core, even though it's been messed with and the cover is damaged? The numbers on the black cover are: Part No.: A31-601-000 Lot No.: 75236 L28 Curious if it's even original for my '78...

Thanks again for the great responses, guys! This thread has been a MAJOR source of help for me. The idle used to hang high whether I was in the car or not, but it didn't really do it yesterday in the garage, maybe due to the heat. Maybe due to all the sensor/component connector clean-up I've been doing? I'll try again this afternoon and have a look at the return spring and the throttle blade and let you know what I see. I should probably open that up and clean it out a bit. I did pull the AFM at one point last autumn and clean it out with AFM cleaner, but there wasn't much effect, if any. I have replaced all the vacuum hoses on the driver's side of the engine as well as the PCV, with the AAR hoses being the most recent and the last of them, I think. (All others were done right when I bought the car before it made the trip from LA to Chicago last year). And you are right, I should leave the heater vacuum issue for the future (good call!) and get the engine running right first. So many little things to get caught up on as I go along. One thing I noticed while doing the CSV test yesterday was that my outer boot to the air filter was in good shape, but the one between the AFM and the throttle body seemed to have cracks around the camping points. This could be a source of extra air sneaking in, right? I'll pull it and inspect. It's probably original and getting pretty hard. The outer boot toward the air filter seemed supple, though. Thanks again for the pointers! I'll be sure to update once I get over to the garage.

And another update...tested the cold start valve today as per the FSM for 1978, checked out fine. Did a jump off the battery and she pumped some juice, appears to not be leaking (pulled it and ran the car with the CSV in a jar, and nada). I was able to take her for a ride afterward, and the idle seemed to settle a bit better (hovered more near 1,000 to 1,100 RPM after tweaking the air screw on the AFM and the idle screw), but still runs really rich and the throttle doesn't settle quickly, drops fine from high RPMs, but hovers around 1,200 - 1,400 and takes maybe 5 seconds to settle to normal idle settings. It was in the low 90s today, so I don't think any of the cold start components came into play. I'm thinking my AFM is maybe the culprit? Going to start testing that next...any tips are welcome. I don't want to start cheating the AFM to dodge a bad sensor, etc. I also replaced some damaged vacuum hoses today. I did my best, but there has been a butcher in there (some hoses were not connected on the battery side) and I'm not sure everything is hooked up correctly, still researching the FSM with regard to the routing and vacuum readings. The "ET" section seems to have the most information, but not much. This is some uncharted territory for me. My heater does not work presently, either, thinking all those vacuum lines need replacing, and a possible flush of the heater core. Anyway, we're getting there...