darom

I'd also put the multimeter leads directly on the fuel pump and watch the voltage when someone operates the throttle. Voltage drop there won't do any good to a fuel pump operation.

Thanks! I guess if the opening is 6 AN/ 0.34 in, I will need a 3/4 in countersink bit.

My protunerz fuel rail has the same shallow o-ring surface for the CSV line. @HusseinHolland what is the name of the drill bit you used on yours? It looks like a deburring bit (45 degree?). I am heading out to Home Depot, will look for one. Thanks!

I hope so too, I just ordered the same fuel rail from Protunerz. That chamfer for the o-ring will be the first thing I will be checking when I get the part.

Found this link to a pre-made timer relay to get some cheaper build ideas: http://www.okaauto.com/EFITimer.html

Thanks for looking into it! I have the same issue, I am running the MSD-2225 fuel pump, and I think it doesn't have any drain-back valve. I installed one of those Amazon special one-way valves after the fuel filter in the engine bay. After a while, it stopped working. When I took it apart, some corrosion inside created the seal/membrane gaps. What do you think about wiring the fuel pump relay + 5-10 sec timer relay into the ignition switch (ON position)? The fuel pump wires run under the carpet on the passenger side (at least in my 76), providing an easy access.

@Captain Obvious Any updates on your fuel pump-priming project? I use one of those $5 time relay boards to run a 1979 fuel rail fan blower for 10 minutes. It is manually operated. The relay board is attached to a bigger relay to handle the load of the blower motor.

With the correct AAR orientation, at the beginning the idle was at 1100 rpms, within 2.5 minutes I saw the idle speed slowly going down. Once the air regulator valve was completely closed (i could check it by pinching the AAR hose - it didn't affect the idle speed), I set the idle at 850 rpms. It is steady. I will check the car again in the morning to test, but I am positive the issue with high idle/AAR has been resolved. Also I was able to shut the engine down by screwing the idle screw in. I couldn't do it before. I still need to redo my oil pan gasket to get 1-2 in of vacuum : - ) Big thanks to everyone on this forum.

I think I figured out the AAR issue on my car. Yesterday I was bench testing one of my AARs and noticed that blowing air one way allows for more air to pass through vs the other inlet when the curtain is closed. I checked onine pictures of the AAR orientation in the engine bay of other 280z owners and realized that my AAR was/is installed backwards (the electric connector is facing the firewall). I am going to change it tonight after work and see if this improves the idle speed 🙂 If this is the case, I have had the AAR installed wrong way for at least 5 years now. And you know how it feels ...

Zed, I removed and inspected the inside of the AAR after a few test runs. Before the installation, I did the bench testing of it with a 12V and adjusted the curtain to be closed when the coil warms up. Since it can't block air 100 percent, there is still some residual air flow which contributes to 900-950 rpm idle. If I pinch the rubber hose for the AAR, the idle immediately drops to 800 rpm, and it remains steady. In both of my tests so far the idle RPM was the same.

Thanks for the ideas! I might be building a simple on/off solenoid with a cheap time relay board set for 2-3 minutes: https://www.amazon.com/Position-Normally-Pneumatic-U-S-Solid/dp/B06WGRLX58/ref=sr_1_13?crid=5V29CNB41DD4&keywords=12v+solenoid+1%2F4+in&qid=1700523538&sprefix=12v+solenoid+1%2F4+in%2Caps%2C86&sr=8-13

Some ideas for an AAR 🙂 Manually operating heater valve: https://www.amazon.com/Universal-Conditioner-HV-2211C-Control/dp/B003R31YVQ/ref=m_crc_dp_lf_d_t1_sccl_3_3/138-5872620-2836123?pd_rd_w=UzJvp&content-id=amzn1.sym.76a0b561-a7b4-41dc-9467-a85a2fa27c1c&pf_rd_p=76a0b561-a7b4-41dc-9467-a85a2fa27c1c&pf_rd_r=34220AX20P78YFH9FKCE&pd_rd_wg=aMQD8&pd_rd_r=2ead7de1-3b51-42e0-b3bf-74fcaef91ae1&pd_rd_i=B003R31YVQ&psc=1 or this with the timer relay (I use a cheap timer relay for my injector rail blower/fan from a later model): https://www.amazon.com/4inch-Normally-Closed-Electric-Solenoid/dp/B074Z5SDG3/ref=sr_1_31?crid=3G17GRQMH50IC&keywords=solenoid+valve+1%2F2in+12V&qid=1700513498&sprefix=solenoid+valve+1%2F2in+12v%2Caps%2C84&sr=8-31

Hi guys, I ran the smoke tests, found a few areas: 1. valve cover gasket, firewall side - big leak. 2. electric EGR solenoid (leaks inside, not vacuum hose), EGR valve (inside again, not the vacuum line). little leak. 3. oil pan gasket - medium leak here. 4. oil dipstick - little leak. I replaced the valve cover gasket with a cork one, it still leaked. The valve cover/cylinder head appear to be flat. I ordered a silicone one from Milkfab Engineering ($28), the new gasket sealed all the leaks. I made a delete metal plate for the EGR. Replaced all the old spark plugs with new NGKs, replaced the fuel filter. The aux air regulator was replaced with a 300zx unit, which was adjusted to shut. It takes about 6 minutes. The valves were adjusted. The car's ignition timing is set at 15 bdtc, idles at about 900 rpm. The vacuum is at 17. The car has a strong pull, no hesitation while accelerating. Observations: 1. I think once I replace the oil pan gasket, I might get another 1-2 of vacuum. This is a spring project (it is too cold in the garage). 2. The resistance pod is at 2k Ohms. I still can't kill the engine maxing it out at 5k. 3. The 'new' AAR is unpredictable. If I leave it alone, it will close (not completely) after 6 minutes. Two different days while testing - one day the idle is at 900-950 rpms, today it was at 800 rpms after warm-up. I feel the AAR shutter 'curtain' doesn't guarantee the same closure. I would like to replace it with a similar mechanical device (like the 240z choke inside). Does anyone know of a part that might work? This way I will open it up when the engine is cold, and close it when it warms up. Once closed, I can set the ideal 850 rpm at idle. 4. When the engine is cold, within those 5-6 minutes of warm-up period, if at idle once rev'ed up, the engine will pop through intake. 5. I still can't kill the engine with the idle adjustment screw. Hopefully, it is the oil pan gasket leak that causes it.

Thanks Yarb, for looking it up. Just in case I ordered a gasket, Mahle MS16717 (composite) from rockauto. I found a forum chat in the Help Me section where a 280z owner compared it to the OEM from Nissan, they looked identical (with the exception of the price). The plan is to do a valve adjustment as well.

Thanks for the resource! Found the part number, 14035-N3500, gasket manifold, looks like it is available. Will order/replace it once I confirm the leaks in that area.