mjr45

Zed, that makes sense since mine is a 75 and so is my FSM. I don't think those 2 wires have anything to do with my rich condition. Different stuff in FSM's maybe just another Datsun legacy. Len, no worries, life happens. Sounds like a nice lathe, maybe you can start turning some custom parts for your Z, swing arms, mustache bar etc.

rcb, nope don't have it in there and in my FSM diagram EF 15 shows the thermotine switch location, go figure. I've come to the conclusion that not all FSM's are created equal.

Zed, the 2 white wires appear to be coming out of the wiring harness well above the plug for the ECU, so I'm kind of a little lost as to what they are and what they do. In some other previous thread, I'd read they were "possibly" used to connect an altitude switch, but I'll at least do some electrical checks (I'm just starting to be able to use my digital meter, I'm an electrical novice and get lost easily) on those wires and the #11 and 26 terminals. Mike

rcb, can't find anything up there except my old e flasher unit that I haven't been able to figure how to remove.

Thanks Len, this whole rich running thing has me totally baffled!

Len, there are 2 white wires that are just hanging by the ECU. I was under the impression that there was an altitude switch in the AFM. Thanks. Mike

Just as a thought, would being at altitude (9000') have some type of effect on the air/fuel mix I know that with less air at altitude most engines run lean ? My intake vacuum is steady at 14 (which is OK by my calculations for altitude), there is no altitude switch on the AFM and my fuel pressure at idle is 38 w/o vacuum and 33 with and pressure leaks down to 10 after only a few minutes of not running. The FPR is new as are the injectors. Maybe an adjustable FPR is the answer.Thanks.

Len, no I didn't switch back and forth between the two, it was just a butt dyno feeling. I'll know more when put in some new plugs and get a reading from them. I still think the AAR is a POS which I can lose when I get a HellFire.

rcb, mine is 75 production date 7/75. Fastwoman, it was a little weird on changing the ECU, the one I swapped in was from either a 76 or 77. On my original, there are pins in each slot and the other has a lot of pins missing(pins that weren't in use I assume), so if its from a 77, I might get the lean drift from it and thus cure my rich condition. I also used your idea and put a fuel pressure gauge in the engine bay. I get 38psi with the FPR vacuum line off and a steady 33 with it on, so the fuel pressure is OK. I'll just have to run it a while and see what the plugs look like. I was also going to ask you what happens if I remove the AAR and CSV from the system, besides hard to start when cold? Thanks Mike PS: Decided not to sell her.

AS a final, final note, I changed the ECU with a spare I had just to see what would happen. The engine ran much smoother and the "butt dyno" felt much improved. I still thinks it runs rich but for now I'll not mess around since it runs far better.

78 Z Car, very nice job, I'm a little over 2 years in my 75 and on the home stretch. I was going to sell her this Spring but have changed my mind, there are a few things left to do, just got some new 16" rims and tires, didn't really like my rims.

Never mind, I found the answer to the tire question, still not sure on the hub centric stuff.

First, I'm looking at some 8.25X15 rims that I really like and want to run 225X50X15 tires, any issues? Second I've been reading about hub centric rings and wondering if they would really do much since I know the Z is "lug centric?" These are going on my stock 75 280, currently running a 7.5X15 rim with no issues. Thanks.

Sarah, I would love to see how far I can hit the AAR with a 9 iron, hoping for 110 yards.

Just to close this out, I adjusted the AFM per Atlantic Z and I've only been able to take it once due to snow, which I don't drive the Z in. It "seemed" to run better, smoother if you will, but haven't put enough miles on it to tell if its still running rich on top of that, I'll be getting a HellFire, so maybe it doesn't matter any more!

Len, Nice work, I'll start saving the $. Mike

Very nicely done! You'll find lots of company in San Diego for your Z.

Lenny, its a balmy 45 up here @ 9000', just went down and ran the Z to warm it up, my garage stays about 30° all winter and I have to run the kerosene stoves to get some heat down there. Mike

Len, I just want it to run well or at least better. If you want another ECU, I'll be glad to send you my spare, but from what I've been reading on your ZFuel thread, it sounds like you have plenty, I can't wait for your project to be completed, the idea of being able to diagnose problems and tune sounds awesome. Mike

Len, I have another ECU, untested and untried, that I may put in to see if it makes any difference, but I'll wait until I get 100 miles on her after the AFM cal. just to see, I'm not expecting much but we'll see. Thanks, I'll be in line for the Hellfire when its done!

Ok, today I pulled the AFM and ran all the tests in the FSM pg EF 51 and 52, the tests of the potentiometer were the only ones that are off, Test 1 reads 204 ohm and test 2 114 ohm so its put them both off by 14% the voltage dropped when I opened the vane as it was supposed to.. I then calibrated the AFM using the Atlantic Z write up(Thanks Blue), it was off slightly to the lean side. The test of the CTS showed 4.5 ohm completely cold and 0.47 after getting up to 150°. Now I can only wait for the Hellfire to come out soon!

Lenny, you have the answer to my prayers. Congrats on both the new babies, your life will change forever, but it will be great fun. Thanks again for all the great work.

Zed, the cam/notch timing has been checked 3 separate times. Falls off was poor terminology on my part it just flattens out above 4200. The exhaust is new from the manifold back with 2 1/4" pipe and new muffler, no cat. or resonator.

Captain, I don't drive it much in the winter, just an occasional start up and let it warm up, so I may disconnect the CSV and see what happens. Its a balmy -14 right now, so I won't be doing any work on it today, go figure..

Zed, I don't recall the brand of injector, but I'm positive they were not higher flowing than stock per the vendor. I believe the engine was running rich prior to me starting the project, but I can't be absolutely positive since its been over 2 years ago and at the time I started I didn't really check. Since I've done the rebuild(everything except new rings and crank bearings) its run rich, however since I started the AFM adjustment it has improved slightly which again makes me think it has something to do with the AFM circuitry. I kinda thought that adding a pot to the CTS would enrich and not lean it out. As I've stated, it runs well, so maybe I should just leave it alone! Thanks. Mike