darom

Can you plug the Cold Start Valve fuel hose and try again? Maybe it is flooding your engine with fuel? You can also remove it and observe how long it sprays fuel for.

Not sure if you would like to explore the route Houssein took with his car and a 3 second fuel primer circuit: https://www.classiczcars.com/forums/topic/68866-new-problem-fuel-pressure-drops-off-75-280-l-jet-w-composite-injectors-protunerz-rail-3-bar-fpr/#comments My '76 was also plagued with fuel draining while sitting overnight or even within a few hours. I installed the fuel pressure gauge to monitor it. It seems that all my previous fuel pumps (generic one from Rockauto, MSD 2225 including the current, Walbro 255), did not have the built-in drain check valves. At some point I installed an anti-drain check valve inline past my engine bay fuel filter, it didn't help much. What helped when I switched to Microsquirt which primes the fuel pump for a few seconds before you crank an engine. It builds a nice fuel pressure and the car starts every time.

Thanks, Jim, for posting the video! Would you happen to have any photos of how you/muffler shop installed the resonator/rest of the exhaust? I have a welder, but will probably use the pipe spreader to make it easily removable with clamps. I found some posts from other members posting various reviews of their MSA headers/premium setups and commenting on some fitting well (around the rear diff) and some not so much.

Richie G, I have been also looking at some exhaust 'drop-in' kits and probably would get an MSA premium one (coated version). What bugs me is that they found a new welder shop, which has 3-4 month wait period and I can't find any reviews of the new shop's quality of welding. Good luck with your search and look forward to seeing the final results on your car. @jfa.series1 which 12" resonator did you end up installing (model/make)? I don't like loud/droning noises and will probably do what you did. Do you have any video with the audio of the exhaust sound? Thanks!

Pomorza, i'd also recommend to apply some fuel tank JB Weld epoxy to the inside/outside of that one connector with the rubber washer. I had to replace the brand new sending unit with another one from zcardepot, because someone overcrimmed the rubber washer inside of it. My car had a big fuel leak at the car show when I filled up the tank full. The replacement unit looks better, but i don't want to take any chances.

Unfortunately, the only spare one I got, has busted threads too.

There is one from Protunerz, on the expensive side though ($280): https://protunerz.com/products/datsun-l-series-billet-thermostat-housing-set-water-neck

Awesome news, Chris! Glad they worked out for you.

AFM #1, $100, at some point of its life it was rebuilt (there is a sticker). When I purchased my 1976 280z in 2009, the car had a running engine with this AFM. The PO opened it up at some point (the cover wasn't properly glued). The AFM passed all the test per FSM, page EF-51 - EF52. Pins 8 & 6 = 182 Ohm, 9 & 8 = 103 Ohm, 36 & 39 with flap closed - no continuity, 36 & 39 flap at 8 or more degrees - continuity, air temp 75-80F, 27 & 6 = 2 kOhm, 27 to ground - no continuity, applying 12V to 9 & 6 -> voltmeter leads on 8 & 7 - while opening the flap, voltage decreases. AFM #2, $200. I bought a re-manufactured unit sold by the Python Injection company in 2011 (sold on Amazon, have a receipt, the car has had 985 miles since then). The unit was never opened, and is an excellent condition. Very clean inside. I passed my CA smog multiple times with this unit, I have a smog certificate from 2017 if the buyer would like to check out my CO, HC, and NO numbers. Per FSM tests: 8 & 6 = 181 Ohm, 9 & 8 = 104 Ohm, 36 & 39 flap closed, no continuity, at 8 degrees or more -> continuity, air temp 75-80F, 27 & 6 = 2.14 kOhm, 27 to ground - no continuity, applying 12V to 9 & 6 -> voltmeter leads on 8 & 7 - while opening the flap, voltage decreases: Aux Air Regulator #1. $60. Part A32-600000 UNISIA JECS, made in Japan, tt was installed on my stock 76, applying 12V, it takes about 5 min to close: Aux Air Regulator #2, $60, Part 22660 45POO, A32-618 M14, Jecs. Tested, takes about 7 min to close. Attention: the connector's top plastic notch is to the right side. It can be filed off to make it work with the stock 280z connector: Aux Air Regulator #3, $60, part 22660 20P10, A32-000 M13, Jecs, takes about 6 min to close. Attention: the connector's top plastic notch is to the right side. It can be filed off to make it work with the stock 280z connector: 1/1976 Fuel Tank, will need to be boiled off/potentially re-lined due to the some corrosion. The tank never sat with used bad gas, i always filled it up with the off-road no corn additives gas during the winter storage. The overall condition is good, with one dent at the bottom (see the picture with an arrow), $200 (prefer a local pickup in Madison, WI, the shipping will be around $160 in a nice s30.world box): Ignition Transistor unit, $40, part E12-12A, removed from my running car. I prefer paypal for payment or Zelle. Thanks, Den

Hello, I am getting rid of some parts I have accumulated throughout my 1/76 280z ownership (since 2009, total number of miles driven since then => 985), shipping extra: dropping resistor $45. Part A15-000-002 Tests per Ef-56 page: 43/1-41 6.5 Ohm, 43/1-40 6.5 Ohm, 43/1-38 6.5 Ohm, 43/1-37 6.5 Ohm 43/2-56 6.6 Ohm, 43/2-55 6.6 Ohm dropping resistor $45. Part A15-000-004 43/1-41 6.5 Ohm, 43/1-40 6.5 Ohm, 43/1-38 6.5 Ohm, 43/1-37 6.5 Ohm 43/2-56 6.5 Ohm, 43/2-55 6.5 Ohm Electronic fuel injection relay $50 each. Hard to find item. Quantity 2. Part A13-000 001. Both passed all the tests per EF-54 - EF-55 pages of FSM. ECU, Part A11-600 000. Lot No. 6322. $60. Removed from my running car before the Microsquirt upgrade: ECU, Part A11-600 000. Lot 8214. $60. Tested it in my 280z. FYI: The number of contact pins is less: ECU, A11-601 000, Lot 7511, untested. $40: Fuel rail from a 280zx which I installed on my 76. Datsun removed a few rubber connecting joints improving the design. It comes with a functioning fuel pressure regulator. $75: Rubber boot AFM to the air filter. $45. Part 16578-N4200. I bought it new in 2009 (have a receipt). Pliable, rubber is in an excellent condition. I found one small rip (see picture with an arrow), it doesn't go through, no air leaks: I prefer Paypal or Zelle for payment. Thanks, Den

Are your new injectors low or high impedance? Have you checked your injectors' resistance? If only half of injectors are firing, is it possible your dropping resistance pack is not working?

Yes, my original bumper pads were in a good shape as well, reused them. I applied the double sided 3M sticky tape to hold them in place.

I hope this saga post is over. I tested the fuel pump running off the fuel jug and it worked without any hesitation, the FPR maintained the 43 psi of fuel pressure. I dropped the fuel tank and found very fine sediment of rusty 'sand' at the bottom. I couldn't fit my endoscope into the fuel bowl to check the condition of its sock, but I think it is covered with crap creating major flow restriction for my pump. I took apart my 100 micron pre-pump fuel filter and didn't see any sediment inside (good news). The sock did a decent job preventing rust particles from getting into my fuel filter and pump. I bought the s30.world early 76 fuel tank and it is a piece of beauty/construction. It is an exact replica: I also replaced my evap fuel lines (they looked old and stiff, but with no cuts). It took 12 days to get the tank, s30.world has a warehouse in the States, no import tariff BS fees. I just wish the web site would send a tracking email. I contacted them directly and haven't heard back. The tank was also very nicely packaged in a sturdy box. I did initial fine tuning of idle in my TunerStudio since now I have a good fuel pressure. Thanks to all of you who contributed to the ideas.

Hi nowak1981 I have a set of used/previously running injectors from my '76, resistor packs in case you need those too. You can DM if you are interested. I converted mine to the microsquirt setup with EV6 style Bosch ones. Regards, Den

I did the return line restriction test - the fuel pressure went over 60 psi (max on my FP gauge). I have a spare Chinese FPR knock-off I used to have, I can replace the Aeromotive with that one. I need to rig up a temp fuel canister and try running the car off it. If I have an occasional fuel restriction in the tank's fuel pickup area, that might explain all these issues. I also considered pulling the drain snake down the main feed fuel hose/line inside the tank to see if it clears anything. Although the thought of a piece of debris in the future causing a break-down on a side of the road is not 100 percent comforting.