Captain Obvious

I've been asked what I look like. My answer is Captain Obvious. I bet he makes more than me...

That's Logan 5. It's a cheesy movie considering today's special effects, but it's a classic sci-fi story. How do you maintain utopia? Step one: Don't have any old people. At least they didn't eat them. You know... To serve man. (how many other references can I stuff into a few short sentences? )

I'm no expert, but... 1. No. You need the engine turning faster than can be accomplished by hand in order to get good compression test results. 2. I've dissected several brands of oil filters in the past and have been dissatisfied with the internals. As a result, I've now switched all my vehicles over to Denso filters that I get from Rock-Auto. It's a pain because you have to plan ahead and can't just run down to the local parts store, but IMHO they're really better. 3, Not Champion. Use Japanese plugs in a Japanese engine. Denso or NGK. 4. If the points aren't all burned up, cratered or have a lump of material migrated from one side to the other, then you can probably save the replacement for later. You should replace them once you get out of the "just trying to get the engine running" stage though. 5. Ask Wheee! 6. "Did I forget anything?" Yes. Of course you did.

Awesome! My kind of problem!! A non-problem! So either it was just the wiener in the warp drive from taking off the AAR and starving the engine for air, or there's an electrical intermittent connection in your wiring tangles. You'll find out at the most in-opportune time. But even if it isn't keeping you from passing smog, you might want to take some time off from other projects on the car and clean that stuff up. I've found a great sense of peace knowing that all my EFI connections are new, clean, and tight.

The oil spray bar is there, but it's not to be trusted. The tell-tale angle of the tips says it's at high risk of coming apart soon. Especially at the rear. I'd get a replacement in there before you put any significant time on the motor.

Yup. that's the exact situation where the BCDD is supposed to help, not steady state on a dyno. The BCDD will also help reduce the amount of oil pulled past the rings and valve seals when the cylinder vacuum goes up when you let off the gas and the intake manifold vacuum spikes. Especially on a worn engine. On my first Z with it's worn out engine, I used to get a terrible eye-burning blast when I completely let off the gas at very high RPMs. I believe I have a much better understanding of the system now, and looking back, I don't think my BCDD was doing anything. That extra rich mixture (too rich to burn), combined with a whole bunch of oil getting pulled past worn surfaces produced a bird dropping cloud of unburned HC's. I was a new work force entrant then just trying to get to work. Now I'm a tree hugger.

POR-15 is a moisture cure polyurethane coating. It doesn't "dry" in the common sense, It "cures" with combination from humidity moisture in the air. If it's cold and very low humidity (like it may be in Canada at this time), it would certainly slow the cure. It'll be ready by spring.

It's been longer than 30 years. They should send that car to Carrousel. That's about the worst I think I've seen. Woof!

The only time the BCDD does anything to decrease emissions (reduce HC) is when you are coasting and have a high intake manifold vacuum. So unless they measure the HC while they are decelerating driving the car, or blipping the throttle and seeing what the HC's do while the RPM's are coming back down to idle, then the BCDD won't make any difference to your emissions test. Under steady state conditions like idle or 30mph steady cruise, the BCDD doesn't do anything and has absolutely no effect on performance or emissions or anything at all. Under steady state conditions, it's just a closed valve. However... Don't get me wrong. I'm a tree hugger at heart and am glad to hear that you are proceeding with a plan that keeps your BCDD intact. Just clearing up some of the technicalities about the operation. Oh, and Wayne is the man.

Hmmm. Other things to consider... In the later (latest?) years, 78 I think, they stopped putting the altitude correction nubbin at the bottom of the BCDD. Probably except for CA. So I don't know how detailed your visual inspection is, but you might need one from 77 or one from a CA 78 car. The final version still has an adjustment screw underneath, but doesn't have the bellows inside for altitude correction. Seems like the kind of thing that every state except CA would not have let them get rid of. There's one of those stubbier BCDD throttle bodies sans altitude correction for sale right now in this thread: https://www.classiczcars.com/forums/topic/61556-280z-oem-parts-fuel-ignition-door-stuff-grill-etc/ Other thoughts? Again, not knowing how rigorous your CA inspection is, but the energetic Z owner could be able to disable the BCDD internally and prevent any leaks while still having it appear externally as though it's fully functioning. Not that I would encourage such behavior, but if it's a trade off of selling the car out of state or driving it...

Cool tool. It's not a direct measurement of airflow (like the flowmeters are), but it's better than nothing. I assume set them to zero (or at least the same between the two) to match them before starting the engine? There's no guarantee that the distance from the top of the carb dome to the piston inside is the same between carbs. I would also be a little tentative about driving around with those on the car. You won't have any suction piston damping and will lean burst when you press the gas pedal. One backfire (front fire?) and your dial indicators will likely be slammed to the limit and probably damaged.

Pretty much every Z I've messed with is in this category. AFM's adjusted to account for vacuum leaks. Idle speeds adjusted to account for BCDD leaks. Etc...

Well don't get all hopeful yet guys. It's just a theory. The simple (the Obvious) one to look into. Hopefully it's that easy, but it's still a potentially failed avenue. However, in the end of all this, I do hope you completely clean up all the wiring going to the sensors in the throttle body. Clean, shiny, well packaged.

Well to me, that's a tiny bit of "consolation". Consolation that your car isn't absolutely perfect and incredibly cheap. I was starting to get sore from kicking myself.

Glad to help in my own little way!

Try this... Make sure your battery is up to top charge (after all the fruitless cranking) and disconnect the connector to the CSV (which will disable the CSV). Then hold your foot on the pedal "a little bit" (like where your foot would be when you are cruising on a flat level road) and then crank it to see if it will start. Now, don't expect instant operation... I removed my CSV a while ago and I can definitely tell that it takes longer to start without it. Not enough to make me want to put it back on, but definitely longer. Might take me five to ten seconds of cranking to get it to fire if the temp is 40 or lower? Doesn't sound like a lot of cranking when you read it like that, but count "one-one thousand, two-one thousand, etc" for six seconds and picture yourself holding the key while you do that. It's a significant amount of time and longer than what you've been doing in your videos.

Well I don't have any hard numbers for you, but IMHO that cold start valve looks perfect. I took a quick look through the FSM to see if I could find some real numbers and came up empty. There may be some flow measurement numbers in there somewhere for the CSV, but with a quick review, I didn't find any. Only thing I DID find was in the FI manual... On page 16 where they are describing the operation of the CSV, they say "the fuel injected Z-car needs a choke system which supplies very large amounts of fuel only during starting." So the factory expected amount of fuel is "very large". I think you nailed it.

No technical input (at this time), but props for the Predator reference.

And that color scheme... Deep blue with a wide white stripe? Makes me ill. Who would do that to a Z???

Figure out why about what? Why the cold start put out a lot more fuel than the individual cylinder injectors? Because it's designed that way. Seems completely normal to me. I still think the obvious explanation is that you are flooding your engine by trying to start an engine that was working properly when there was a significant bypass around the throttle plate (the AAR). You removed that bypass and didn't add extra air from somewhere else, but you kept the fuel the same. Did you try holding the gas pedal down a little bit while you cranked the engine? That might not be it, but it's so simple to try!

As expected, I don't see an obvious smoking gun, but here's a couple things to think about and/or look into. First, all that TVV thing does is block the vacuum to the EGR system until the engine warms up. It should be a closed valve until the engine warms up and this disables the entire EGR system. You can "manually" disable the entire EFR system by pulling the tube off the underside of the throttle body and capping it. This won't work for you when inspection time rolls around, but just for troubleshooting this current problem, it would be easier if that thing wasn't hanging off the engine. And as a caveat (1a) to the above... The vacuum source for the EGR system comes off a ported source from the throttle body that presents no vacuum at idle anyway, so that whole thing shouldn't be doing anything at all unless your foot is on the pedal. It's similar to the distributor advance vacuum... Nothing at idle, nothing at WOT, but highest at light cruise position. Second, the simplest suggestion would be to try pushing down on the gas pedal a little bit while you try to start the car. Your AAR looks to be open a significant amount and once you took that off the car and blocked the holes, you have removed that amount of idle boost. Your car may simply be completely clamped shut now and can't get enough air to even idle. Try holding the pedal down a little and see if it'll run. Third, I see the rubber stopper in the intake duct for one side of where the AAR used to connect, but I'm not sure what you did with the other side over on the throttle body top. Looks like aluminum foil or something? The point is... The AAR connection side coming off the throttle body is the high vacuum side and needs to be sealed very well. Even more important than the side coming off the intake duct. They're both important, but because of the high vacuum on the intake manifold side, that side needs to be even better. Fourth... All that wiring going to your potentiometer and the water temperature sensors in the thermostat housing? Ewwww.

I saw the pipe, but didn't know what it was. Miles and miles away!!!

@Jeff G 78 Wow... That is many many miles away from what I consider a good time. Woof!

Can you take a decent res pic or two of the engine? Maybe someone will spot something?

Forget the dash... Are those un-rusted original frame rails? Don't drive it like you stole it. You totally stole it. Just don't drive it like that. It'll give it away.