NewZed

You have a picture of wires hanging in space, in an unidentified car, in the Miscellaneous Tech sub-forum. Reading below 12 volts, but no indication that the engine is even running and the alternator spinning. Pretty sure "the dude" knew more than you, but his work looks pretty shoddy. Describe the car, the engine, and what the voltmeter or ammeter does with the engine off, idling, and revving. Those will be good clues. No Carnacs out here.

The two things that you think are minor are probably major. Melted wires, and all of the loose wire ends from the missing electrical components. Find the loose wire ends and insulate them before you waste too much more time. The melted wires at the connector block. Most of the harness wires pass through that block. In the Body Electrical chapter there's a diagram of each one, with a color code and separate diagrams of what they're connecting. Identify the connector and its melted wires and you'll probably be on your way to finding the short circuit. The headlights only working on either of high or low is a typical dirty dimmer switch problem. Spray some contact cleaner in and work it back and forth or take it apart and clean it. Voltmeter working is a good sign.

The wheel diameters and tires you listed are normal, not relatively small. The big rims and low profile tires are the oddities. This site was around well before the curb scraper rim fad developed. Should be plenty of info out there about what you're looking for.

^^^ I almost posted the same thought yesterday. I bought my car to do the small block chevy swap but I'm on my second L6 instead.

This plus the latest supports the fuel pump proposition. I was just looking for a solid case. But. It could also be a clogged filter, hindering flow from the pump. That would be cheaper. Anyway, it seems like a supply problem. At least you're down to two possible items to check. Assuming it's not something in the tank.

You're looking for a wire that comes from the fuse that is shorted directly to ground. That's what would cause a fuse to blow immediately. So, for example, on the reverse light the wire to the switch has power. When you put the lever in reverse the switch completes the circuit and the power travels through the switch to the reverse lamp and then to ground. If the power supply wire got pinched and shorted the power would have no resistance from the reverse light and would blow the fuse. That's just one example. Each load - the light, the blower motor, the relays - has a short section of wire with power. Many of the loads are actuated by grounding the end of the circuit with a switch (like the brake lights), rather than providing power at the beginning. Those are where the problems come from. A short circuit across a lamp socket (the electrodes touch at the base of the bulb) is a common problem that blows fuses. Even the loads that have a switch providing power at the beginning of the circuit still have a short section of wire with power, to the switch itself. On your car, the diagram seems to show that power runs through the inhibitor relay to the ignition switch then a fuse on its way to the reverse lights. But it's an odd format and I can't really tell what it's showing, if the fuse is inline or at the fusebox. You might try disconnecting things, like the ignition switch, or the combination switch, until you can get the fuse installed. At least you'll narrow it down to a smaller area. Edit - forgot to say: your fuse box cover should show which circuit that fuse is for. That would be an important clue.

Did you try the Google? Seems promising. You're not on a phone are you? https://www.google.com/webhp?tab=ww&ei=dq5PVNe5B8j8igLU9ICABg&ved=0CAMQ1S4#q=240z+lq4+accessories

The numbers don't support the need for a new pump. They are are correct for no boost. Not clear. That's all I'm saying.

Parts found lying around usually are there for a reason. Does the 1991 325i 5 speed even have exceptional value? What would be the benefit? I've driven a BMW stick shift, 1984 325i, and the lever action is rubbery and mushy. Didn't like it compared to the plain old ZX 5 speed.

I meant learn more stuff. "Or something" means that you "don't know". 7.4 psi (15 inches Hg) of boost plus 36.3 psi ambient = 42.7 psi. That's maximum fuel pressure at maximum boost. Not WOT with no load. No boost, max. pressure = 36.3 psi . Or ~38 depending on which book you're looking at. Some FPR's run a pound or two high, so 38 psi is common. The 1983 FSM is pretty bad, so good luck. There's nothing in there about 44 psi though. stupid_fast was right, give the engine a better tune than new cap and rotor. You're kind of spinning your wheels, and about to replace good parts, without a general systems check.

Here's a diagram showing some red-blue wires. A few things to check, like the reverse switch (it's surprising how unprotected and dirty that area is on the transmission. Seems like more shorts would happen there), inhibitor switch, blower motor, etc. http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/240z/1970_240z.gif

Sounds like an exhaust leak. Why would you be looking at your slave cylinder? You said it doesn't change with clutch actuation.

You should retitle your thread as "LS1/T56 clutch disengagement problems" or something like that, and add more detail on the clutch parts. Maybe your .875 bore master isn't right for the "stock" slave cylinder. "Stock" for what, for example. Anyway, there are few guys on here that have been deep in to their LS1 clutch problems. You just need to catch their eye. Edited out my confusion on "slave cylinder".

1975 280Z's have the oddball R200 pinion flange. It has its own unique bolt pattern and bolt size (might be the same as the 300ZX's, not positive. Definitely not like the other Z cars though). So if you cut a 1975 R200 driveshaft, it's only good for 1975 R200's. Beware the 1975 R200. And the R180 pinion flange location in the car is not different than the R200 (I've never had an R180 but all signs seem to show this). You can swap an R180 for an R200 and use the same driveshaft. Except for the very early 240Z's with the forward-mounted diffs, that use a shorter driveshaft (which is usable with the 240SC/71C swap though, except 1975 cars). A good general reference - http://www.zhome.com/ZCMnL/tech/R200.htm And a couple of excerpts from the 1978 PD chapter.

Have you measured resistance of the coolant temperature sensor circuit at the ECU connector and compared it to the chart? How do you know the new one is even connected to anything?

Does this mean it runs well cold, then runs poorly after it warms up? There's no time-frame to work with, besides "starts out driving" and "then a short time later".

Swap rods.

Did you try turning up the idle speed screw? Don't know what carbs you're using but most have an idle speed adjustment. More ignition advance typically increases idle speed. Could be that all you're really doing with your timing adjustment is increasing idle speed. Gotta start somewhere. On the cam - can you see anything like that shown in the attached picture? With the straight side of the chain tight.

Here's a write-up for the 280Z thermostat temperature sensor. The CHTS does the same, from a different location. http://atlanticz.ca/zclub/techtips/tempsensorpot/index.html

Mid to late 90's Honda and Mitsubishi SUV's have a metal inline Schrader valve that you can cut out and T in to a rubber fuel hose. If you're by a wrecking yard. Just leave it in. You said you wanted ideas to try while you waited to get a gauge. The potentiometer can be slipped in between the two bullet connectors on the CHTS circuit. Zero hacking required, completely reversible.

Doesn't Comp Cams supply instructions? Most cam grinders keep the original reference marks. #1 should work. You didn't say anything about carbs or EFI or Megasquirt. Could be that your problem has nothing to do with cam or ignition timing. Or your damper timing marks are off.

Here's a good reference for brake options. If you're going to do it, might as well get it right - http://forums.hybridz.org/topic/38499-brake-upgrade-faq/

You're using poorly setup stock parts as a reason to replace them with expensive non-stock parts. This is how budgets blow up. Anyway, the thread has deviated in to philosophy. You'll find plenty of opinions on the forum to support spending money. Good luck.

That wasn't the point. Many of the older stock systems, for whatever reason, run lean with stock parts in good working order. The potentiometer lets you add a little bit of fuel over the full fuel curve. It's a simple tuning aid, not really a fix for a bad part. But, of course, measuring fuel pressure so you know what you're actually working with is the best idea. If fuel pressure is fine, do the potentiometer. This is the common lean AFM symptom - "Taking it on the road, with more than 15-20% throttle applied it would stumble, sneeze, and front fire very harshly."