Zed Head

It's about time! Timing is everything! Good times! How's the mileage? I advanced my timing a few degrees at a time until I was at 7 degrees over FSM recommended. The engine got more responsive each time. 2 degrees is pretty retarded. A doggy engine is a typical sign of retarded timing. Probably should have asked about it. Don't forget to followup, it's a good thread.

I sent it mainly for the pictures of the collars, so you could see what one was. Check out this link - http://www.oreillyauto.com/site/c/detail/WAG0/F131353.oap?year=1972&make=Nissan&model=240Z&vi=1209169&keyword=clutch+slave&forcedVehicle=true&pt=01352&ppt=C0015 What's interesting is they list the same slave cylinder for early 240Z's up to 280ZX's and including 240SX's. So I would guess it's not a big difference maker, or they are not different. Just another thing to consider. Also, the slave cylinders tend to go bad without obvious signs. Pull the boot off and see if any fluid comes out. It might be leaking mid-stroke, giving only partial movement. Which reminds me, the master cylinders do the same thing. But harder to tell. If you didn't have the odd drivetrain, all signs would point to a bad slave or master cylinder.

This web page has some good information - http://zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html If you're trying to match the bore of the master to the bore of the slave, have you considered a smaller bore slave? A lot easier if you can find one that fits, and the end result is the same. I don't know about specific interchangeability, but wouldn't be surprised if there was one out there.

Conedodger, this car uses the water temp sensor with the attached temperature vs resistance curve. I'm not sure what the CHTS sensor uses. But no continuity or high resistance would be "very cold" to the 77 ECU. Funky-P, from your answer, I'm guessing that you're looking at the wiring diagram also? Measuring 10 to 20 instead of 36 to 39. Still no numbers though, and no reports of fuel pump working (you can test it separately from the relays, just run 12 volts to it and listen) or fuel flowing. Don't forget that 0, 100, 180 and 1,000 ohm will all show "continuity." You really need the numbers. Read this thread from the past. Lots of good measurements and a positive outcome - http://www.classiczcars.com/forums/showthread.php?t=37299 . The major difference to your situation is that her car was running at the time. Still not clear why you're focused on the AFM. Confirm fuel flow, fuel pressure and spark first.

Use the "Edit" function and fix it...

You can do it either way. Still not clear on how you could be using page EF-52 but report "between 11 and 13 on any of the pins, 6, 9, 8, 7 in any combination." You didn't give any of your test values... 6 to 8, 9 to 8, 36 to 39. Sounds like you're checking things, but you're not telling the values you're getting. Or whether you have power to the fuel pump, spark, etc. Are you looking for the magic loose wire? Most people confirm fuel pump power, then fuel flow, check fuel pressure if you can, turn the engine over, check for spark, etc. Good luck, keep going, then come back later and re-read these ideas.

Well, thanks for following up on the response. I'm not sure which test procedure you're using though. The procedure I've used is on Page EF-52. You should get 180 ohms between 6 and 8, and 100 ohms between 9 and 8. Those are the two limits of the potentiometer and determine the feedback to the ECU from the flap position. If you're getting 11 - 13 ohms then you must be shorted somewhere. But then you shouldn't get proper readings from the flap. So we have conflicting results. Are you using a decent ohm-meter? 100 and 180 ohms are on the low side and may be out the range of your meter. Between pins 36 and 39 you should get continuity when the flap is open. That powers the relay that powers your fuel pump. Pins 6,7,8 and 9 should be tested to ground and should not show continuity. No shorts. Are you connecting 12 volts and measuring volts out for your flapper test? Have you confirmed that the fuel pump works and that you're getting spark? It's good that you're digging in but you might be jumping too far ahead. Edit - forgot to mention that you can take these measurements at the connector inside the car, with the AFM plugged in a grounded (or installed). The hardest part is figuring out the pin numbering at the connector but there's a picture in the manual, plus some of the pins are missing (not used). This way you test the harness and the component together.

He said he's a student so hopefully he's just young and ignorant, and doesn't realize the racist origins of his remark. It is sad though that I'm hoping for ignorance...

You might put your test numbers out here to be looked at. Some one could probably help you decide if they're terrible or not bad. Your car should start and idle with a bad AFM anyway, as long as the fuel pump contact is working. Your 77 still has the contact in the AFM if it is stock. I would get it started and idling first, then you'll have a better idea of how bad the AFM might be.

Fixing old posts - the relief valve in the stock Datsun fuel pump actually has a range of 43 to 64 psi. For future searchers...

Fixing old posts with new knowledge - The stock Datsun fuel pump reliefe valve (bypass above) had a range of 43 to 64 psi, not just 43.

Just fixing old posts with new knowledge. The JEGS liquid-filled gauge I discussed actually turned out to be very inaccurate once it got warm. It read low, disguising a high fuel pressure problem for quite a while. Stay away from liquid-filled gauges in hot environments, especially the inexpensive gauges.

You should download the Factory Service Manual (see the web site below) if you don't have one, get a multimeter and test things. The AFM test is pretty simple (it's in the Engine Fuel section). Some here have had good luck just cleaning the AFM contact area. I bought a remanufactured AFM but only after lots of testing to confirm it was bad (the resistance readings were off and it popped and bucked when I drove it). Spend a while testing components and you'll know what to think about when it still doesn't work right. Deoxit is a good contact cleaner but the others work well too. The electrical connections tend to corrode over time. http://www.xenons30.com/reference.html The 76 manual is broken in to chapters, the 77 wasn't last I looked.

Another Oregonian. Woohoo. How come you're not watching football? The thermotime switch only comes in to when play you're Starting. Maybe, instead, you jumped the temperature sensor that tells the ECU how warm the engine coolant is? If so, you told the ECU that your engine was very hot. Or you think you jumped it but actually just disconnected it. In that case, you told the ECU that your engine was very cold. That would give lots of rich black smoke. Did you just get the car? The symptoms look like those of a bad AFM. I had a bad one and mine idled fine, went well at 3/4 to full throttle, but did what you describe at part-throttle. There is a test procedure for the AFM and most of the other EFI parts. You can spend a lot of money replacing parts, when all you might need is some contact cleaner. By the way, your first post was pretty well formatted except for the large, bold font. Second one looked like cell phone.

I was in the FSM the other day for some reason, and realized that on Page EF-15, the description of the relief valve says "43 to 64 psi". I too was under the impression that the relief valve let go at 43 psi and have stated that several times myself in previous posts. I'm not sure how I missed the 64 psi upper limit but it should be noted that 64 psi is a possibility. So it is possible to have a plugged line or regulator and get pressures considerably higher than 36 psi. It would be interesting to pinch off the return line completely on a stock fuel pump and see where the relief valve lets go. Might not be safe though.

Thanks for reminding me. I do remember reading some posts about that, with descriptions of the bearings that would work. I'll search it out.

Or your local high school auto shop might take a measurement for you for free. Although you might be too close to having just got out to want to go back and visit.:sick: Just a thought. Your car would be a great example of the basics of fuel injection.

Thought I would put this out there for future searchers who are hearing noise from the vicinity of the water pump. Check your AC idler pulley first, if you have one. The external heater core to engine hose sprung a leak on my 1976 280Z and sprayed half of the coolant out as I drove home one night. I replaced the hose, refilled with coolant, then soon after (days), I started hearing what sounded like bad bearings from the front of the engine. I thought for sure that my water pump bearings had cooked themselves after the hose had burst. But before I got too deep in to it, I remembered that my AC idler pulley had made some noise in the past, fixed at the time (apparently temporarily) with a drop of oil and some WD-40. I took the AC belt off and was back to quiet running. Winter's coming and it need charging anyway, so it's a spring project now. Just putting it down for the record. It's easy to loosen the AC idler pulley and remove the belt, to see if that's the source of the noise.

I have to ask, just to satisfy my curiosity. Are you avoiding measuring the fuel pressure because the gauge is expensive? I know that I did not want to pay $45 just to measure something once or twice and then put it on the shelf. Or did you measure it and it checked out okay? If you're not going to measure it, it would be nice to know why. You can't have good fuel injection without proper fuel pressure. As far as the ECU swap, be careful, you could end up in this guy's boat - http://forums.hybridz.org/index.php/topic/95747-z31300zx-ecumaf-to-280zxt-problems/page__p__900526__fromsearch__1#entry900526 Plus you'll never get any help from the SU guys then...

Dave, you seem like a very helpful, knowledgeable guy. But I have to say that it is ironic that the "Electrical Hero Wanna Be" says to ditch the electronics and go back to mechanical. I'm just sayin'. It's funny.

The BCDD is not designed to "hold the idle" at low RPM. It is designed to maintain a certain pressure in the intake manifold at high RPM, throttle closed operation. I have read that they can get stuck but giving a high idle, not a low one. And the AAR is on its own circuit, designed to hold the idle up for a short while after starting. You could take it off and test it or disconnect the hose and block both ends to see if it has an effect. The BCDD is described in the Emissions section of the FSM and the AAR in the Engine Fuel section. 15 mpg is still pretty bad. How's the fuel pressure? Don't forget to get a new low pressure fuel pump or low pressure regulator if you go carbs. Otherwise, you'll really be running rich.

2nd edit - So, it sounds like you can buy a new cylinder, take it and your key code or the key you want to match to a good locksmith, and get back to brand new, one key operation. I didn't realize that it was that simple. I didn't fully understand Unkle's Option #2...

Is replacing the wafers a locksmith job or a DIY? That plus a new code-cut key seems like it gets you back to brand-new, with a single key for locks and ignition. Minimizing the number of keys. Everyone is happy.

I had a new key cut for my car using the code number on the glove box door. More accurate even than measuring with a micrometer, I assume. The old key would barely work on one door lock only, not at all on the other. But, unfortunately (or not depending on perspective), the new key still easily comes out of the ignition switch at any point in its rotation. Just one real-world experience with a new key on a 1976 car. I added a fuel pump cutoff switch because of this, mainly to stop joyriders since my car wouldn't be worth extended effort to steal.

Are you II, III or IV? What is a 500Z? Ford 5.0 engine?