Zed Head

Loosen locknut, turn rod with pliers, make rod longer. Two inches is a lot of adjustment though, you might have something else wrong.

It would depend on how well you understand fuel injection. There are no bolt on and go systems available, as far as I have heard. They all take some planning before buying parts, and some expertise in engine tuning after everything's bolted together. On your car, assuming its the stock carbed engine, everything from fuel lines to the gas tank, fuel lines to the engine, fuel pump, cylinder head, and intake manifold would need some modification, or replacement. All to work with whatever engine management system you decide to use, to control the firing of the injectors. The more common way to get fuel injection in to a 240Z is to swap in a complete 280Z engine and wiring harness, with ECU.

You can buy degrees of completion ranging from a bill of materials to be assembled yourself, up to essentially complete boards and wiring harnesses. I'm sure you've seen this company's site but I'll post it for the record - http://www.diyautotune.com/ They seem to be the most established for Megasquirt, although there are others out there.

Here is a recent post from zcar.com along those lines. Tony D has posted on this forum in the past. Most of the Megasquirt threads you see are for turbo or modified applications, so a straight AFM/ECU to MegaSquirt comparison is hard to find. Reply #4 has the relevant comments - http://www.zcar.com/70-83_tech_discussion_forum/micro_squirt_qestion_899882.0.html

I did miss the injector comment. I wonder where MSA gets their injectors. I bought my FPR from a local guy on Craigslist, brand new. An Aeromotive 13301 universal adjustable unit. As for the comment about why they leak down, I sent Aeromotive an e-mail about it and Brett Clow of Aeromotive replied back that they knew about it and it had been discussed. He said that they were planning to put a new FAQ on their web page with the following text (plus a little more) - "The stock EFI regulator was engineered with a mandate to hold fuel pressure for 30-minutes after engine shut-down. This is an government regulation with which new car manufacturers must comply. Unfortunately, the mechanism used to hold fuel pressure when the engine is off, has a derogatory affect on a high-flow, adjustable regulator’s ability to create and control fuel pressure when the engine is on. Aeromotive places fuel system performance when the engine is running, particularly running under high load, at the top of the priority board. Anything, such as a checking mechanism in the regulator valve, which compromises fuel flow and pressure control under high-load engine operation, is therefore eliminated. We believe this no-compromise approach to fuel system performance is one of the reasons Aeromotive fuel pressure regulators are universally preferred by enthusiasts and racing professionals alike, around the world." He said they would also add some text to the instructions about the pressure leak-down. I just checked their web page and don't see it yet, even though on the 24th of March, 2011 he said it would be up in a few days. It's one of those things that marketing people would hate so maybe it got quashed, or maybe they're just very busy.

When I got new injectors my hot start problem went away. But it came back months later a few times after some long drives in the summer. Then, after replacing my FPR with an Aeromotive unit (because my stock one went bad), it has gone away for good, I think because the Aeromotive FPRs leak down rapidly. The downside is that if I don't prime the fuel lines with a switch on my fuel pump circuit, it takes a lot longer to start, especially when cold. Aeromotive says that the leak-down is part of the high-flow design, but I think that it's a flaw. I bought the relatively inexpensive BWD injectors. I think that they sealed well when new but probably leak occasionally when hot, after they got some wear and heat. With the Aeromotive FPR that doesn't hold pressure without flow, no more leaking injectors, no more hot start problem. But every start requires a prime. I will probably go with more expensive injectors and a better FPR in the future now that I know what know. I'm not suggesting buying an FPR that doesn't hold pressure, just adding some perspective. I would guess that new factory injectors probably won't leak like the aftermarket ones do. Or maybe a better, modern injector design. My 95 Pathfinder doesn't leak down, even after weeks of sitting, and it has 200,000+ miles on original injectors. If you wanted to experiment, you might put some sort of manual bypass valve around the FPR to the return line and depressurize the lines immediately to see if leaky injectors is the source of the problem.

I've seen a similar tool but it doesn't plot the numbers. Is that one available on the web? There is something odd about your attached picture though. Maybe you didn't redraw after putting in new numbers. 3rd gear plots the same line but 4th gear doesn't even though the values are the same for 3rd and 4th, between the two transmissions. Anyway, I wouldn't mind a link to the site if you have it.

You can take an ohm-meter and see if the wire is a redundant ground (like some relays have extra grounds). Check continuity from the body of the switch to the wire stub. If the stub is not connected to the body then your fix won't work. Maybe you could lay a drop of solder from the ire stub to the body or stake a tiny screw in to the remaining copper wire of the stub to make contact. I had the same problem but had enough wire left to fix it. Eventually I stopped using the extra pickup coil though, that's how I know about the momentary low idle. The whole concept is kind of an engineering band-aid to keep the idle up while the engine gets warm. Kind of strange really.

Can't tell which of your cars you're talking about. But... Federal models 1976, and I believe 75 and 77, have another temperature switch that "tells" the ignition module to use the other pickup coil in the distributor when the engine is cold. The extra pickup is set with an extra 6 degrees of timing advance. The ignition modules have a separate circuit just for the extra pickup coil. It went away in 1978. Any ground from that wire should work as long as the switch closes when cold. It actually affects cold running, not just the start. Disconnected is like having a warm engine. If you leave it disconnected your idle will be a little low in the time between when the AAR closes after you start a cold engine and the engine gets fully warmed up. It's been proposed (can't remember who it was) that you could put your own hand-operated switch in the circuit to give a manual 6 degree timing control.

grantf, you've made some serious progress from your original "change spark plugs, get injectors cleaned" post, one month and a few days ago. Not bad, I don't think I moved that fast after I got mine. Congratulations. You'll be on to Megasquirt soon, I can tell.

I might go check it out just to see what a decent-shape old 240Z looks like. All I've really seen so far are worn-out 280Zs and ZXs. The seller hasn't done anything outrageous, except leaving himself out as the 2nd owner, now fixed. Maybe he's legit.

More on this case history of a 240Z re-entering the market - Down to $5,000, from $8,000. Original cost = $2,300, plus any extra title transfer/transport fees, etc. http://portland.craigslist.org/mlt/cto/2473492309.html 71 DATSUN 240Z 4-SPEED ...(same text as above)...$5,000 503-995-6692 DATSUN NISSAN Z 240 280

Did it work before? With the electronic ignition? Or is the ignition system new and has created the tach problem?

It looks like a ground wire, probably for connection to the block (based on it's position and size). If you have a volt/ohm meter you could check for continuity to the negative cable terminal. If it doesn't run to the negative cable, then turn the key to On and check for voltage.

Wow! I thought this grammar form was US-based only. Fascinating. Are you from New Zealand or did you move there from the States. I'm not kidding, seriously, I am interested.

Just for fun. He's down to $5,900 and has changed the ad to show second owner. Still looks like a nice car. A new CL posting - 71 DATSUN 240Z 4-SPEED , 83000 ORIGINAL DOCUMENTED MILES. NICE INTERIOR AND EXTERIOR. STRAIGHT BODY, AND BUMPERS. AC WITH PUMP. ALL LIGHTS IN AND OUT WORK. ALL GLASS IS GOOD. DOORS OPEN AND CLOSE NICE. ALL GAUGES WORK INCLUDING THE CLOCK. ORIGINAL POWER ANT. WORKS. ORIGINAL WOOD STEERING WHEEL. CAR IS ALL ORIGINAL EXCEPT WHEELS AND TIRES. TIRES HAVE 80% PLUS TREAD. RUNS AND DRIVES GREAT. DRIVES LIKE IT SHOULD NICE AND TIGHT. WELL KEPT AND MAINTAINED. STILL HAS ORIGINAL PLATES AND TAGS. ADULT SECOND OWNER. $5900 503-995-6692 DATSUN NISSAN Z 240 280 http://portland.craigslist.org/mlt/cto/2473492309.html

You didn't say if you're running carbs or EFI with your L28. If you're running fuel injection, you need a high-pressure fuel injection pump. One for or from a 1975 and up Z car would work, 1975 - 1978 would probably fit your car best. If you're running carbs you need a low pressure pump, or, depending on what year L28 you have, you might be able to install the mechanical pump. Maybe, I don't know for sure. Look at your old engine, you'll see the mechanical pump on the front of it.

Check the contact switch on top of the steering column also (or close, wherever the headlight switch stalk ends). The tiny circuit board can get loose and let the contacts lose contact. You can unbend the four crimped hold-downs, pull the board and clean the contacts. When you put it back together, crimp the hold-downs extra tight. If you want to check it before taking it apart, just press down on it with your finger and see if the lights start working. The dimmer switch that beerman mentioned should also be looked at. You can spray contact cleaner in to the switch area and work the lever to clean it up. Or you can attempt taking it apart. I had the loose column switch go bad on a 78 parts car, and a dirty dimmer on a 76.

I used a couple of greased putty knives to get the front bushings in. One one each side, and press it in. They weren't too big by 2 mm, but the concept should still work to give some leverage to compress the polyurethane. Drywall mud blades, putty knives, any thin flexible metal should work.

There's really only a couple of things left, if you're sure that al of your parts are Nissan stock and correct for the year. Are you running the stock ignition system, no dual spark or MSD type? I only ask because the ECU fires the injectors after every third discharge of the coil. That would probably show up as a higher tach reading though,since the tach is on the same circuit. Does your tachometer work correctly? It's usually a bad idea to replace parts without being sure but for $10 you might be able to at least look at another ECU. This guy is in your neighborhood and has your ECU #, I believe, for $10. He's just cleaning house. Worth a thought - http://forums.hybridz.org/index.php/topic/100893-ecu-blowout-10/page__p__945646__hl__ecus__fromsearch__1#entry945646 I have read of ECUs going bad and running rich, but never for as long as you've been driving. I don't know enough about the inner workings of the injectors to guess what happens to them when they get really worn. Maybe the flow rate goes up. That's really all there is to the system - ECU opens injectors for a "calculated" amount of time (based on temperatures and other inputs) and fuel flows out of the injector at an assumed rate. I just thought of one more option and again I don't know what would happen if, but the TPS has three positions, idle, cruise and full enrichment. Maybe your TPS is stuck on full enrichment. The ECU thinks that you have the throttle close to wide open. It could also be stuck on Idle, I suppose, since that is also an enrichment position. Again, probably best to test at the ECU. The pin numbers are in the Fuel section of the FSM, and are the same at the ECU plug. I would do that before anything else, it's easy.

Here's something from left field - is it possible that someone from the past installed turbo injectors or some other higher flow injector? That would lead to lots of extra gas being squirted, even though everything is right on. I believe that there are ways to tell them apart but I don't know what they are. And are you sure about the mileage? The inside of your tail pipe should be all black and sooty with that much gas going through there. Mine has a light coating, still running slightly rich, at ~20 mpg.

He's edited this CL post down to $6500 already. 1971 DATSUN 240 Z ONE OWNER 503-995-6692 - $6500 (SE PORTLAND) Date: 2011-06-28, 12:47AM PDT Reply to: see below [Errors when replying to ads?] 1971 Z CAR NICEST ONE IN TOWN EVERYTHING WORKS EVERYTHING.FACTRY AC,DUAL SIDE DRAFT CARBS,FOUR SPEED,YOU NAME IT IT HAS IT,# MATCHING,ALWAYS INSIDE,VERY WELL LOVED BUT NEEDS A NEW HOME,DONT WAIST MY TIME IF YOU DONT HAVE CASH DEPOSIT NO TEST DRIVE,CAR WILL NOT BE SHOWN ON RAINY DAYS,(503)995-6692 ,KEY WORDS:JEEP,WRANGLER,CHEV,DODGE,FORD,DATSUN Z,240,260,280,Z CAR,TOYOTA,NISSAN,HONDA,SUBARU,CAMARO,NOVA,CHEVELL,$6500/OBO/TRADE?(503)995-6692 CALL I MAY TRADE YA CASH IS KING MAKE ME A OFFER 503-995-6692

You are right, Nissan went to the -11, wide-gap plugs in 1977, presumably to match a stronger ignition system. My ignition system is modified from the original 1976 specs. And I should run the resistor plugs (BR instead of just , to go with my resistor wires, to avoid electrical noise problems with my EFI system and ignition. My original post is more about what's going on with the highly popular NGK spark plugs. In today's auto parts stores most counter people won't know what a BR6ES or BR6ES-11 plug is. They might not even know the NGK brand. Knowing that NAPA part number 7910 = NGK B6ES-11 or NAPA 3824 = NGK BR6ES-11 might help someone out. Most store's systems can't find the NGK part number, they have to look in a separate paper cross-reference book, if they can find it. Even on MSA's web site, you can't tell what NGK part you're getting, only that the plug they have listed is for your year and model.

thanks. I just figured out that that site is actually a front for www.sparkplugs.com. The disclaimer is at the top of the page. Here's the real NGK site - http://www.ngksparkplugs.com/index.asp Same stock numbers though.

The resistance should not read the same unless the engine is completely cooled down, like overnight. The air sensor is in the AFM and reads air coming in to the engine. The water sensor is in the thermostat housing and reads how hot the engine is. It looks like you're making progress though. All of these small things will add up. That is a crappy photo, but the AFM does look pretty normal. A dab of silicone is put on the screws at the factory. If it's broken it's been tampered with, if not, maybe not. Have you checked the cold start valve? Besides the six injectors, it is the only other place for fuel to be pumped out of the gas tank. Since it's summer-time, you could just remove the fuel line to the CSV and plug it. Don't just stick a threaded bolt in the hose, there's 40 psi behind it. If it has been leaking, you'll see a change. Or you could pull the valve and see if it leaks. 10 mpg is way low. There's something big going on. Are you sure that your odometer is working?