DAW

J Taylor: another way to check the quality of the spark is with a tester made by KD (and others) and sold in most parts stores. It's a tester spark pluf that has a ground clip on it and you plug it into a plug wire. The tester gap is set for conventional or high energy type systems, and you fire the car up to see if the spark jumps the gap and that it is a bright spark. Now that your car is starting but running ragged, make sure you didn't cross up your wires in troubleshooting. If an electrical breakdown, the car can idle fine but will break down under load, like pulling up a hill. It may recover when you ease off the throttle. If idle is OK but all else is off, did you check throttle position switch? DAW

It sounds like you have more than one thing going on. If you really think you've got an intermittent IC module problem then replace it. If a new one's too expensive then pull a used one in a JY and look for a smashed vehicle like it was being driven before it went to the JY. Also check application, the module is pretty basic and may fit Zs as well as Maximas and even 4cyl Nissans of similar year. Check the engine harness well. It sounds like you may have a bad, loose or corroded connector to the temp sensor since you get black smoke. DAW

It's easy to check. Pull the valve cover and have a look. Bring the crank around to TDC, with both lobes for #1 cyl pointing upward (compression) and look at the indexing marks. DAW

The PCV system vent hose looks like a good location for the BOV discharge to go, although I think placing the tee closer to the large hose (turbo intake) end rather than the valve cover end might be best. DAW

J Taylor, the purpose of testing the spark at the coil wire, then at the end of the spark plug wire is not to see if you have a bad plug wire that's causing the car not to start. A thick blue spark at the coil wire and a thin orange spark at the plug means there's some breakdown in that segment of the secondary ignition, e.g., deterioration of the underside of the center of the rotor letting the voltage ground to the top of the distributor shaft. You can see this if you dissasemble and inspect. Testing is faster. DAW

Don't worry about the distributor winding up by hand and springing back, you are just working the mechanical advance springs and weights, it's normal. DAW

Good advice, and remember that the battery has to have electrolyte, so if it's way low, top it off with distilled water and charge it. Check it with a small hydrometer: if a cell is dead this will show it (replace the battery), or if on a charger, all cells are bubbling except one that's totally calm, you need a battery. DAW

Above are all good suggestions, but you need to do your basic troubleshooting to narrow down your search for the source of the problem. Is it a fuel delivery problem, ignition, or both? Troubleshooting Algorithm: Start with rule-out ignition: when the problem occurs, take the coil wire out of the cap, place a phillips screwdriver in the wire terminal and rest it on a metal surface of engine/compartment so that the metal of the screwdriver is about 1/4" gap from the suface (valve cover or one of three strut mount bolts works well), you want to place it so that you'll see the spark while you're cranking, i.e., through the windshield and below open hood edge. Should be a thick spark with some blue in it. If there's a spark but it's thin, orange and weak the problem could still be ignition. If there's any spark, then replace coil wire and repeat with a spark plug end of a plug wire. If there's good spark there and the car's not firing; problem is in fuel delivery. If feeble, or no spark at plug wire end and coil wire end, then check coil wire with ohmmeter, should be about 1,000 ohms resistance per inch of coil wire. If bad, replace and retest for good spark. If you've narrowed it to the electrical side, then make sure the distributor shaft is turning when you turn the engine. If so, try a replacement ignition module and go on from there. Test the primary and secondary circuits in the coil to see if they pass re specs. If ignition passed, troubleshoot fuel system. If you had spark but plugs were soaked with fuel, replace them or spray electric motor or brake-cleaner on them and let them dry then install. Crank it to see if it runs. If it does but is rich, pinch off the fuel line (vise grips with a rag works) near the fuel filter and run till stalls to dry cyls out. If dumping fuel, then it's probably AFM or temp sensor, possibly pressure regulator or ECU. If plugs were dry with spark, pull output line off fuel filter and cautiously place into container. When cranking, there should be brisk fuel flow. If none, check input line to filter, if flow, replace filter. If none, then check fuel pump relay for power output to pump (green wire on your car), if present, check same wire at pump, if present; replace pump. If you had good fuel flow at filter output line and plugs are dry with good spark, then the easiest way to proceed is with fuel injection test devices like sold by J.C. Whitney. Plug the tester light into an injector harness terminal. If no signal, then suspect AFM, ECU or harness to it or ignition trigger signal to it. Confirm that it would run if it had injector signal by hooking up injector testor to injector, activate it (pulses at speed you select), and crank engine which will try to run on one cylinder. Hopefully, before getting too far through this algorithm you isolated the problem by testing and eliminating components rather than the "shotgun" approach of replacing expensive items which weren't at fault. Having done it both ways; this way is better. DAW

Check all your battery and starter connections (including the slip-on connector to the small brass terminal sticking out the front of the solenoid). Often corrosion causes too much resistance and the car will do just what you described, A failing or undercharged battery would do it too. DAW

Phil, Looks great, although it maybe needs a subtle final touch to break up all the open space under the tailights. Have you seen the thin, chrome wrap-around bumpers from the older sports cars like XKEs and Fiat 850s? The early Fiat 124s had them also, but were a bit wider and heavier looking. These rear bumpers wrap from the side of the car, like the original 240Z, around the back, and turn down verically about at the license plate area; i.e. there is a right and a left and neither crosses the midline. DAW

There are two water temp sensors in the thermostat housing, one above the other. I think the upper one made of brass with a black center and green wire coming out of it is the computer sensor, but you should confirm that as I'm not 100% positive. Disconnect the green wire with the car running; if black smoke pours out the tailpipe, then it's the computer sensor. DAW

How about with the "B" pillar blacked out? i.e., the vertical chrome of the door window edge and the vertical quarter window edge, leave chrome outlining the perimeter of the windows but black-out the vertical between them. DAW

I used a potentiometer to calibrate/select for best all around resistance value, then installed that resistor and removed the potentiometer. However, if you're leaving it in place maybe a stepped type switch would be best (with detents) so that you can give it a certain number of clicks if you need richening while driving so that you can keep your eyes on the road and still adjust acurately. DAW

Sorry, the tester has nothing to do with the type of "bad" injector you're talking about. How about putting a fuel pressure gauge in the circuit to test pressure. You've replaced the fuel filter? DAW

Are you vented properly? RE checking the injectors, J.C. Whitnetr sells a f.i. tester which lets you plug into each injector plug to see if the light pulses in the tester for that injector. Very useful in troubleshooting. DAW

I think the roller is about 1/3 of the way from the front. There are right and left rollers and I think you can tweek the spring-steel to put more pressure on the glass. DAW

I can't find my '72 240Z factory service manual right now, but in it is a single 2 bbl. Hitachi carb version of the 240Z. I've got one of these rareintake manifolds. The Hitachi may be no good, but I could include an adapter for a downdraft 2 bbl. Weber (DGV 32/36 type), and these carbs are readily available. I would sell this aluminum Nissan manifold and Weber adapter for $60, plus shipping. I know the 2 bbl. setup was used on L20A engines in Japan. It was on an L26 in a '72 240Z that I bought long ago. I remember the car was quick to fire up and very driveable. I remember seeing a car magazine article once with an LD28 in a 280Z. The cast iron cyl head and fuel pump assy. are HEAVY, to the point you would need stronger front springs. However, the diesel exhaust ports are standard square port and a turbo manifold would bolt-on. This, with an intercooler, would be a high mpg, unique car. You'd need to bolt-on a rear sump pan (L28ET). DAW

The f.i. heads also have a larger manifold bolt, that the E31 doesn't have, along the upper row of manifold-to-head bolts. You could drill these and notch the intake ports for injector clearance, but I'd recommend a different approach to what you are trying to accomplish. The N47 head off the '82-'84 Maxima is already set-up for f.i., has chambers about equal in volume to E31, has a good quench chamber design (like P79/P90, but with a lower roof), has 35mm exhaust valves like L28 heads (E31 has 33mm), and has hardened seats for unleaded gas. The one drawback over the E31 are the round/linered exhaust ports vs rectangular. The rectangular flow better, and there is a wider availability of headers and better-flowing factory cast manifolds (and turbo manifold) for rectangular ports. I'd like to know if anyone has done porting on the round-port head to make a transitional port shape with the best possible match to gasket in order to use rectangular port manifolds? DAW

Scotty, I think one reply above may be on the right track with the water temp sensor/wiring. It is possible to cross the connectors in the harness which runs over the manifold and get thermotime wiring and water temp wiring crossed. Or if the water temp sensor is open, the infinite resistance signal to the CPU tells it that the car is at sub-zero temp and sends in maximum richness/huge fuel dump into the engine. If this were the case, but you were snugging up the AFM flap spring to compensate, then you'll need to work backwards and undo that adjustment. DAW

I used a potentiometer wired into the water temp sensor circuit to adjust mixture, and for selecting a fixed value resistor for this circuit where I wanted the baseline mixture to be. A resistor can also be placed in the cylinder head temp circuit for mixture control. You'll probably want to adjust/alter baseline AFM doorspring tension before proceeding with the sensor potentiometer or resistor. DAW

You must be getting that vacuum signal from somewhere below the throttle plate (manifold pressure), rather than just above it at idle (ported). Either that, or the throttle is cracked way more than it should be for the engine to idle for some reason (valve timing, mixture, etc), and you're into the ported vacuum source prematurely. How wide is the throttle plate actually open at idle? DAW

Nic, another light that just looks like it would fit is Toyota MR2 Spyder (the newer model convertible, not the old MR2 series) has anyone checked these out? DAW

I'd like to make a rear hatch window out of plexiglass and I'd like to know if anyone has experience with this? I'm thinking I might try taking a glass hatch window (already out of the hatch), place the sheet of plexiglass on it, place a second glass on top (sandwiching the plexiglass), and hook both rear window defrosters to 12 volts for a day or so, with insulating material on the outsides of both glasses to retain heat. Futile? Or would the weight of the top glass (and maybe some added weight) together with the combined heat do something to mold the plexiglass to form? DAW

I've seen a lot of broken ring lands on Nissan Z series pistons coming out of stock 4cyl engines, so I think it's a weak point. The KA24DE piston with floating pin may be a better choice for an 89mm bore engine than the Z24 piston. Silvolite has a division called KD Pistons for high performance street use. Any experience with these? DAW

"Thanks in advance"...is that some sort of pun?? You've got to time the spark as part of the installation of your Crane photocell/shutter ignition. Installation might put you a little off, or a mile off, but it's going to change. Follow the manual. It's best to set static timing to start with: bump engine around until #1 is coming towards TDC on it's COMPRESSION stroke, rotate it up until the mark is at the amount of initial advance you want, and with key on and photocell holder positioned correctly, slowly rotate the distributor until there's a spark from #1 spark plug wire (put a bolt in the terminal/boot and rest it 1/4" from some metal engine surface. When setting, make sure you're rotating the dist the opposite direction the rotor turns to get the best accuracy. DAW