Captain Obvious

That's got to be the most common sentence I've seen in Z car ads. I see that almost all the time! Has anyone ever seen an ad that says "Engine blew and it's been sitting since"? Congrats. She's a beauty! Bountiful suspension tree too. I planted one in my back yard, but it didn't take. Must like warmer weather. [ATTACH=CONFIG]60015[/ATTACH]

That TR-7 ECU is probably a couple generations newer than the one we have. I haven't seen any schematics for our ECU's, but I suspect there are sections that would be very similar despite the newer design. Not all of it, but sections maybe. However, I can attest that those similarities do not extend to the output stage. A while ago I drew up a schematic for the output stage of our ECU, and ours is very different than the TR-7.

I suspect it contains the exact same RTD design as the water temp sensor. The curves are identical. I bet it's the exact same guts repackaged differently mechanically. If you got desperate enough, you could probably physically modify a WTS and stuff it where the IAT sensor goes.

Excellent! Sorry I couldn't be of more assistance. Glad someone else knew what was going on!!

Far be it from me to cast aspersions on an easy fix that took care of the problem, but a clogged fuel filter doesn't really fit the symptoms. However, whatever works, right? If that fixed it, then more power to ya! So before you replaced the fuel filter... What did it do when you floored it? Did it have good power on the highway when you really put your foot into it?

Sounds like you were just expecting too much too quick. One hurdle at a time... If you have to use a little choke until it's up tp temp, then do so. Worry about fouling the plugs later. If you aren't billowing black clouds of eye burning fumes, then I wouldn't worry about it. If it dies when you hit the throttle it's probably running lean. However, if you aren't yet up to temp with the engine, then it will compound the issue. Think about it this way... The colder the engine, the richer it wants the mixture. Where do you have your nozzles set right now, and why did you put them where they are? As for the clear tube method, here's a description and a pic: a) Pull the black rubber fuel line off the bottom of the bowl and drain the bowl Replace the black rubber line with a clear tube that is long enough to loop back up against the bowl body without kinking. c) Fill the carb bowl back up again using a funnel and another piece of tube connected to the fuel inlet nipple. d) As you pour the fuel in, the float will start to rise. When the float rises far enough, it will close off the float valve, and the carb will stop accepting additional fuel. e) Measure the bowl level and compare to the specs on picture EF-46 of the FSM

Haha! Well I'm not ready to claim any progress towards determining what's really going on with z_ya's car. There are still lots and lots and lots of things that could be wrong. I'm just in brainstorm mode trying to come up with hairbrained ideas that fit the problem symptoms well. I think that a voltmeter and a fuel pressure gauge in the skilled hands of someone who has messed with L-jet in the past could shed a lot of light in a short period of time.

How long are you keeping the choke on for? Another way to ask the same question... How quickly are you thinking your car will run well without the choke? The reason I ask is that in my experience it has been "minutes" before the engine runs as desired with no choke at all. Are you thinking that you can start it and then immediately push the choke off and expect it to run with no choke? By the way, any performance issues with the carbs could potentially be traced back to problems with the float bowl level. Did you ever verify your float bowl level using the clear tube method?

Zed, That's a well thought out interesting idea. I don't know if that's what's going on in this case, but it's a neat thought. Move the key to ON - Fuel pump runs and builds up pressure in the rail. Move the key to START - Fuel pump stops - Cold start valve dumps fuel quickly into the intake until the fuel rail pressure is gone. Quick blast of fuel from the CSV is enough to get the car to start, but with no pressure in the rail, there's nothing to feed the injectors when the key is moved back to ON - Engine stalls. Maybe on the second start attempt there's just enough pressure in the system to get over the hump? Maybe on the second start attempt, the thermotime switch has opened and the CSV isn't activated which saves fuel for the injectors instead? Interesting... :bulb:

No. Measuring +12 volts on both sides of an injector is not necessarily a problem. The way the system works is this... One side of each injector is always connected to +12 through a "dropping resistor". You should always measure about +12 on that side of the injector. The other side of each injector is connected to the ECU. Inside is the ECU is a switch (a transistor) which, when closed, connects that side of the injector to ground. When the transistor switch is open, no current flows through the injector and you will measure +12 on both sides of the injector. When the transistor switch is closed, current flows through the injector (which causes the injector to open), and you will measure +12 on one side of the injector, and ground on the other. However... The amount of time that the transistor switch is closed is very short, and your typical voltmeter will not pick it up. Your typical voltmeter will average the signal in some way, and since the amount of time that the injector is connected to ground is such a small amount of time, it will essentially average out to +12. Does that help? Does that make any sense? I'm not sure that your mechanic is familiar with fuel injected systems.

Haha! This has been bugging you since we talked last, hasn't it? :classic: You are a fountain of information. If it's not already on your had disk, you seem to be able to dredge it up from somewhere. I can tell already that the schematic is very different in spots than the 280Z ECU, but I bet the basic concept is very similar. That's awesome! Merry Christmas to me! I am going to have fun with that!

This is a great thread. Koalia, Hope you don't mind all the plating discussion. Jerry, PM back to you.

Jerry, Glad you had enough moolah left after LaSalle to do the Z car parts. Thanks again for the details. Sounds just like what I usually hear. Want nice clean shiny smooth results out? Then provide nice clean shiny smooth results in. GIGO. OK, now for the (hopefully not) million dollar question... How much? What did you pay for that tangle of parts?

Thanks Jerry. I suspect my buddy is getting zinc and doesn't know it. How agressive was the wire brushing prep you had to do? Did you have to abrade off all the original plating, or just get the big chunks of grease and rust off?

I understand the out of the comfort zone comment. I'm a slow decision guy too and my recent snap purchase should be delivered today. Not as big or as expensive as a Z, but same sentiment. Here's to hoping that 2013 will be both of our years!

Thanks for the details Carl. I've got a buddy who does a lot with antique motorcycle stuff and he often gets parts "cad plated". At least that's what they're telling him... Next time he and I get together, I'll poke him a little and try to find out if it's truly cad or if it's really zinc. As you described, they come back dull silver, and not yellow. I've thought about including some parts with his orders, but the results don't look "right" for a Z car. Sounds like it may be a secondary process that could be split stream for his stuff and mine. At this point, my Z is pleasure drive only and shouldn't see any inclement weather. Corrosion resistance for things like hardware is still important, but not as important as it used to be. I had not previously been interested in zinc plating, but Jerry's parts look good enough for me and it sounds like the corrosion resistance would be good enough for my application as well.

So what's the little switch pod by your right knee? Is that an ejector seat? PS - Put a wood shift knob in that thing... :bulb:

If that's original, then I just say "wow". I thought they all turned yellow butterscotch by now! Hoe away!! That's awesome! Want to trade for black? :laugh:

So about the plating... What process was used for the original factory plating? I know pretty much nothing about the subject, but I've usually heard it referred to as "cad plating", and (because that's what I always heard), I propagated that term. Is it cadmium or zinc? Are those parts you just got back done with the same plating material and process as OEM? PS - Those parts are beautiful, regardless of the details!

Unless you have an electric pump, then no. With a mechanical pump only, there is really no good way to see that fuel is getting through the carbs and into the engine without cranking the car. I would suggest two options... Either 1) crank the car until the pump primes and starts supplying fuel, or 2) prefill the carb bowls with fuel using a funnel and short piece of tubing. The engine should run for way long enough for the fuel pump to start supplying fuel by the time the bowls are sucked dry. If as part of the carb rebuild process you didn't already verify the float bowl levels by filling up the carb bowls with fuel and looking at the level using a clear tube on the outlet nipple, then now is your chance and in this case, I would recommend option 2. If you already verified the level with the carbs off the car, then either option will work, however, if you choose option 1, then I recommend you pull the plugs and disconnect the primary side of the coil until you know the fuel system is working properly. That will ease the strain on the associated parts and allow you to crank longer and faster without damaging anything.

Yup. I'm stumped. Sorry. I've heard of a device in use a long time ago that separated a compressed air stream into a warm and cold stream*... Something on old trains maybe? Never studied it, but it always sounded like voodoo to me. Maybe that's what you've got going on? :classic: So do the floor flappies on the side of the air box open enough for you to stick a finger up in there and reach the heater core to see how it feels? I'm grasping at straws, but it might lend a clue. * - The Ranque-Hilsch vortex tube - http://en.wikipedia.org/wiki/Vortex_tube

Congrats! That can't be the original interior, can it? [ATTACH=CONFIG]59457[/ATTACH] Please tell me all the upholstery has been redone!

Yeah, pulling the heater core is no treat. I took my whole heater box out when I had the dashboard out of the car for other reasons, and getting to the heater core then is obviously cake. I took some pics of my box when I had mine completely apart, and I would be hard pressed to believe that the air blasting straight down on the bottom of the shell would split evenly as well. So, all that said, you've certainly got nothing to lose by flushing the heater core. I've got no other bright ideas. How hot is the hot side? The greater the contrast between the two sides, the harder it is to explain any of this. Another question... What do the defrost outlets do when you put it into defrost mode? Is one of them cold as well?

I'm no expert on the HVAC system, but I was deep into mine and I can't come up with any possible explanation for what you're seeing. As for your heater core theory... remember that the coolant runs from one side to the other, not between front and back. With that in mind, a partially clogged core does not support what you think you're seeing. If there were come clogged rods, it might be a little warmer in the front of the core when compared to the back, but not a differential between left and right. If you are truly getting cold air out of one floor vent while getting hot out of the other, then I'm stumped.

My first thought was AAR as well. I'm thinking that maybe it's gunked with sticky PCV system blowby and it still works, but it sticks in place. Theory being that the AAR is supposed to creep open as the engine cools off and by the time you start the cold engine next day, it has creeped open enough to cause a high "cold" idle. If the AAR is sticky, maybe it's not opening like it should, but the vibration and shock of starting the motor is enough to get it to move to the correct position? Then after the second start attempt, it will be OK. So the question would be... Once you have feathered the gas pedal for a few seconds, does the idle continue to struggle, or is it a nice smooth high idle like it's supposed to be? My second thought would be that you are always borderline lean and when the engine is stone cold it just can't handle it.