Cruzzar

What year is your 280z? Only '76 and later need smog checks.

Called yesterday, the Z store MSA) is out of stock. I have the booster pictured on the right. Brakes were working just fine and then no assist, pulled hose and tried to pull a vacuum and could not get one, diaphragm appears to be bad. The booster is in really good condition and quite rebuildable. I want to send it in to a rebuilder myself and get it returned to me without going thru another set of hands. I want to get this car back on the road. Heyitstrama, this is just what I was looking for, I will give them a call, thanks.

My brake booster just went out on my 75 280Z and I would like to replace it but suppliers are either out of stock, want me to send in my booster and they will have it rebuilt or sell me a newer modern booster. I want a replacement booster that has the vacuum port coming straight out that will align with the stock Datsun preformed vacuum line and not the generic one that comes out and then turns at a 45 deg. angle. I have already ordered two boosters (Autozone) that are direct replacements and they show up with the vacuum port that comes out and then angles which is not what I have stock on my car. MSA, RockAuto, Parts Geek, and NAPA are all out of stock. Does anyone know of a good shop that just rebuilds brake boosters?

I did make sure the wire ring was clean and made a good ground after I installed it. Do you think there is one wire or are more than one that transmits the varied resistances to the ECU based on the vane position? I did try to clean the female connector but I can't say I did a good job. Does anyone have a good way to cleans in between the metal connectors? I gave up on trying to clean up the injector connections and just replaced them. They were covered with green calk-like corrosion.

Eureka!!!!!!!! One of the first things that showed a possible problem when I first ran into this problem was my AFM so I replaced it with a rebuilt one but checked it before installation. I tried increasing the fuel pressure as suggested by Siteunseen with no improvement. I was just about to pull the ECU plug and go over the testing procedures to see if I missed anything but instead I called a friend of mine who has some Z stuff to see if he had an old AFM that I could install and see if it made any difference. W E L L L L L L L L L ------- I install this used, grungy one from a friend this afternoon and it WORKS!!! It is not the first time I have ilnstalled a rebuilt item and it didn't work correctly. I don't know what the issue was with the rebuilt one, I had examined the carbon track and it look perfect, it could be the batch of resistors for that portion could have been bad or not the correct resistance because I had already done the FSM's suggested checks on it as a precaution before I installed it. Applying the 12v and looking for reducing voltage as you move the air vane didn't show me anything unusal. Anyway thanks to all who have given me suggestion. I guess if anything I have become a better informed owner which I don't mind. This is no my first rodeo working on car but this issue was driving me nuts because it was not making sense and many of you out there have a tremendous knowledge base with these cars. Will post pictures if I can figure out has to do that when I get it all cleaned up, licensed, insured and on the road.

Zed Head, In regards to the EGR, I have pulled a vacuum on the EGR valve and it holds a vacuum, I have plugged the vacuum port for that hose with still no change in engine performance, I even plugged both vacuum hoses going to the fuel canister with no change. Is it possible that the EGR valve is stuck in the open position and causing a vacuum leak? At idle when warm it pulls 18 inches. of Hg. so I think the pressure regulator is receiving a strong signal. I have not checked the PCV (I don't even know where it is) is it possible that it is stuck? I can pull the hose coming from the top of the valve cover and it will develop a pretty strong vacuum. If there was a large vacuum leak wouldn't it cause a hard start and a lean condition all the way through the rpm range? Engine had good compression (152 low-160 high)

Siteunseen, great idea, I have a tube clamping visegrip pliers and will try that, that should eliminate a lower than normal fuel pressure issue. This is why forums like this are soo good for car owners.

240260280, I unplugged the switch yesterday and problem still exists. I am wondering if it could be an ignition advance problem. I put my light on it and at 2500 rpms I can get about 25 degrees of advance. It it hard for me to get a good reading above that rpm because of the engine wanting to slow down.

Roberts280z, when I replaced the fuel pump I checked the inlet screen and it was clean ( it was a brand new Nissan pump for the 280Z). I put a new fuel filter and blew out all steel lines before replacing the hoses. The fuel pressure check valve will lose about 15 psi overnight. The car will start up in a very short period of cranking and idles very well. Initially on start up it will be about 12.1 and within a short time go to 12.9 to 13. This a/f ratio will change with the changing of the gear in the AFM . The weather here is warm so I don't think the cold start injector is even operating. I have had it unplugged and it doesn't start up any different

Siteunseen, I have cleaned both set of points and checked their continuity, both are good. From what i have read the off idle should come off sooner than 2500. I have pulled the cover and can visually see that the idle points are open when the engine goes lean. I could bend the arm on the go rich (second set of points) and have it engage sooner but this was a running car in good condition when it was parked.

I have had the fuel pressure gauge hooked up as I increased the rpms and it holds a solid 32 psi until it falls on its face at which time the psi goes up. I could do a flow test but at times I can get the rpms up to 3500 if I advance very slowly indicating to me that the injectors have the flow capacity and the a/f ratio is rich enough to maintain combustion. It is like I need to increase the the size of the accelerator jet in a carb. to make the transition from the primarys to the secondaries.

First post here but have been a spectator for about 4 months trying to absorb as much information as possible. I recently obtained a 1975 Datsun 280Z from my neighbor who purchased the car new as an anniversary present for his wife. He owned the local Datsun dealership at the time so all maintenance was done by his dealership. She drove the car until it had about 106,000 miles at which time she got a new car with an automatic transmission (this was a 4 speed car). The car has had a pampered life. She always garaged it and took good care of it. He put a non op with the DMV, pulled the plugs and oiled the cylinders, drained all of the fuel out of the tank and parked it under a large carport in 1995. I purchased it late in Dec. of 2020 and have been slowly working to get it back on the road. I have run into an acceleration problem that I hope someone can help me to diagnose. Since I know from reading past posts , members will want to know details so here goes. I have replaced all of the injectors (corroded terminals and age) and their electrical plugs. New electrical plugs on the water temp. sender as well as tested its ohms output when cold and hot. New gasket with sealant on the cold start injector as well as a new electrical plug. New spark plugs, wires, rotor and cap. Verified distributor advances when a vacuum is pulled. Pulled the gas tank (it was clean with not rust) replaced all of the fuel lines by the tank as well as in the engine compartment. Verified the strainer was clean, replaced the fuel pump (gaskets dried out so much it leaked like a sieve) and installed a new fuel filter in the engine compartment. I replace all of the vacuum lines, pulled every plug that I could find to clean them. Pulled the pan to replace a leaking gasket (had a very small amount of sludge in the bottom) refilled the oil and a new filter. Pulled all the plugs oiled the cylinders, cranked it over until the oil came out of the cam/lifter oiler on top. New plugs, new valve cover gasket, turned it over and it fired up. Let it come up to temp. reset the timing to 10 degrees at 800 rpm as per factory specs (I have the factory service manual). Thought this was really going well until I tried to drive it. It accelerates up to about 2500 rpm and then it falls flat on its face. Pulled the AFM and started checking the pins, all looked good. Went thu the Service manual ECU checks, all looked good. Checked vacuum at idle when warm 18 in. of Hg. Pulled the plugs and checked compression- lowest 152, highest 160. Installed a air/fuel gauge on exhaust right below the manifold and found it idles at about 12.7 and 13.0 when warm. Try to drive it and it goes so lean the engine stops and resumes when back to idle. Checked fuel pressure and static is puts out 36, when running it sets solidly at 32. I know the FSM states 36 psi but is 32 that out of wack? Started looking for a vacuum leak and I thought my problem was found when I found a leaking brake booster so I plugged the port at the manifold and took another ride but no change. I opened the AFM and loosened the spring tension about 5 gear teeth and still no change. If I bring the rpms up very, very slowly I can get it to rpm beyond 3500 but not when driving. I don't think it is an electrical (distributor) issue because of the ability to rpm over 3500. I've checked and cleaned the points on the throttle switch. I've watched the position of the idle enrichment contact and it opens right off idle and the full throttle contact is not making contact when the engine goes lean. Any suggestions or recommendations on what else I can check would be immensely appreciated.