Datsun 280Z Vacuum Advance Operation And Connections

Hey Guys,
This is a video I made in response to a request and hope it helps some of you out with your 280Z/ZX
Go to 7:27 of video for vacuum line connection
For those interested, here is a link to the electronic ignition video explaining its operation/location of components as well: • How Datsun 260Z/280z E...
Thanks for watching!
Jareth

[@Foxyy.Red93]

Just want to say thanks, for a long time I’ve had an issue with timing and this video solved my problem. Thanks so much

[@synthpro]

Hi Tire Chatters, your very much welcome, happy to hear this video helped you solve the problem you were having. Best, Jareth

[@Bassdudecraft]

apreciate this video. i believe i am having vacuum advance problems where once it warms up the car does not want to go above 3k before it falls flat on its face. 1977 280z

[@synthpro]

Thanks, hopefully this helps you out. Something that this could also be is a bad coolant temp sensor, it is related to fuel injection system and basically changes fuel mixture based on temp.

[@allenvaughan1]

But I want you to know, Jareth, that I have an interest in learning what you've presented on your 280Z, because I almost bought a 280z back in 1984, but chose my first RX-7. And I may buy a fixer upper when I move. My house just went live on the MLS today!

[@farmliquidators1441]

Outstanding. I appreciate you sharing your knowledge with us. Thanks to you I found the vacuum line from the T. It was capped off like your canister line. I’m still troubleshooting. Thanks again!

[@synthpro]

Awesome, happy to hear this helped you out. Something else I should note is that a bad ignition coil can cause odd behavior as well.....it will respond almost the same way as if you lose vac advance or have the timing retarded too much.

[@farmliquidators1441]

@@synthpro thanks again. I’m going change the ignition coil this week as I’m still baffled by the issue. My 1978 280z starts right up. I can rev it up and slowly increase my speed going from first to fifth gear smoothly, but if I try to accelerate too quickly I loose power. I can let off the pedal and it continues to run for me to gently continue to drive. The fuel, fuel tank, filter and injectors are clean. The new fuel pump less than 200 miles on it. That’s why I looking into the car ignition system. Thanks again.

[@synthpro]

@@farmliquidators1441 you're welcome. Does this issues seem to be related to temperature or any temp? If temperature is not related, this could be a fuel mixture issue associated with air flow meter. Make sure there are no holes in the rubber boot going between throttle body and air flow meter. If it's more temp related, this could be a problem with the air temp sensor, (located in the air flow meter). Fuel regulator could be a problem as well, you can hook a fuel pressure tester between fuel filter and fuel rail and see what your pressure is doing. If regulator is correctly working, you should see roughly 28PSI at idle and as you increase throttle, the pressure should increase as manifold vacuum pressure decreases, (believe without any vacuum pressure goes up to 40PSI....you can pinch vacuum line running from regulator to manifold and see this increase on fuel pressure meter). Also, a bad fuel filter can cause this behavior as well.

[@farmliquidators1441]

@@synthpro thanks again for going in-depth in trying to help me identify this vexing issue. I changed the coil, cap and rotor this weekend with any improvement. It doesn’t appear to be heat related. Also, it will rev up in neutral or the clutch depressed without loss of power, missing, or backfire. However, if I’m in the appropriate gear and try to rapidly accelerate regardless of speed she Boggs down, sputters, bucks, and at times backfires loosing power. I can let off the accelerator and push in the clutch to gently regain power as the car is moving. I ll try the fuel pressure test next weekend. I think I also borrow a timing light to check the timing. Thanks again

[@benjaminnielsen4288]

Great video! That's some good information on the Vac advance system... I have a 280z that's been modified and I want to put back the Vac advance now that I know what it is and what it does. And now I can test this on my ZX car as well. Thanks for posting this. Good stuff! Cheers

[@ashirrizvi5356]

Can you make a video on the vaccum lines on the intake manifold and the sending unit?

[@steve5926]

My 76’ 280 was doing this on the way home today anytime I shut the car down and restart I can go over 2000rpm no problem but the longer I drive it it will eventually get worse and worse to the point it will lose power up hills and cut in and out above 2000rpm.

[@allenvaughan1]

Well, I am a Mazda and Ford guy. I wish I could help on the 240 and 260Z systems for vacuum advance.

[@synthpro]

No Problem : 0 )

[@allenvaughan1]

@@synthpro well, once I get settled, I'm going to dig out my ARP Pro dgx and send it to you and make a video with it!