280z water **** removal sequence

[MH77280Z]

Guys, I have my dash out, will there be any issue if I start the car without the dash? I mean I need to test the new water **** and that nothing leaks before i put the dash back in. Blower and blower housing is also out. The car will be in neutral off course.

I cannot think of anything, dash only has the gauges etc. rest of the harness I have not touched.

[Mike]

1 minute ago, MH77280Z said:

Guys, I have my dash out, will there be any issue if I start the car without the dash? I mean I need to test the new water **** and that nothing leaks before i put the dash back in. Blower and blower housing is also out. The car will be in neutral off course.

I cannot think of anything, dash only has the gauges etc. rest of the harness I have not touched.

Other than a throttle, key, choke, and a gauge to make sure you have oil pressure...  should be fine.

[Captain Obvious]

There have been reports of the engine not running if the tach resistor is removed, but I have not verified that behavior. Seems unlikely to me. But in any event, having the dash removed would have the same effect as removing the tach resistor.

I can't see any reason it wouldn't run. None of the EFI stuff goes through the dash harness.

And from Mike's list above... You obviously won't have an oil pressure gauge.

[MH77280Z]

40 minutes ago, Captain Obvious said:

There have been reports of the engine not running if the tach resistor is removed, but I have not verified that behavior. Seems unlikely to me. But in any event, having the dash removed would have the same effect as removing the tach resistor.

I can't see any reason it wouldn't run. None of the EFI stuff goes through the dash harness.

And from Mike's list above... You obviously won't have an oil pressure gauge.

Car has been running perfect, no issues with the oil pressure. Whats the concern about oil pressure with the dash out? just no optics?

[Zed Head]

I'm the one that reported my car(s) would not start with the tachometer disconnected.  Actually, if I recall right, it was two cars, my 76 and a 78 parts car that had a good engine.  The 76 phenomenon went away after I changed to an HEI ignition module.  So, it seems to be a thing only with the factory ignition system.

So, basically, if you try to start it without the dash installed and it doesn't start, don't freak out.  You might just be the confirmation case.

Good luck.  One other thing to be aware of is stray wire ends that might be powered with the key on.

[Captain Obvious]

29 minutes ago, MH77280Z said:

Car has been running perfect, no issues with the oil pressure. Whats the concern about oil pressure with the dash out? just no optics?

Yeah, I assume the mention about the oil pressure gauge by Mike was simply due to the fact that with the dash out, you wouldn't know if you had an oil pressure issue or not.

But if you didn't have any sort of oil pressure issue beforehand and the only reason you were messing around with the dash was to make it easier to get to the HVAC system, then I believe the concern is unnecessary. 

Glad to hear it worked out so far. Remember that it may take some time for the whole coolant system to come up to pressure.

Oh, and I'd approve of a picture of you driving the car without a dash installed.   Slow enough to guarantee you weren't speeding of course, since you don't have a speedometer. Hahaha!

[MH77280Z]

Any tips on making sure there is no air in the coolant system?

[Captain Obvious]

Nothing dramatic. Run it with the system a little under filled* for a couple minutes with the radiator cap off. Then top it off, fill up the overflow tank to "F", and put the cap on. Any remaining air should (in theory) work it's way out of the system over the next couple heat/cool cycles.

I've not found the Z to be one of those cars that really needs a complicated burping process.

* The reason for the underfill is if there is a big air bubble in there somewhere it will expand much more than the liquid coolant will. And if the system is full to the top, it'lcould belch out the top of the radiator.