75zhead

well I upgraded to ZX dizzy and blue bosch coil and now everything is perfect. I hook meter to coil and ground and get the rpm reading correct. Thanks for all the help

I know this is a old thread but I have a idea. Your fuel pressure is a hair low, volume maybe too? Easy test is unhook fuel line after filter and run pump for 15 seconds in to a plastic QUART milk jug. Should fill it half way or more. I did this test and only got 25% fill. Half of what it should of been. I was having same problem on my 75 z. Just got the car and it had sat for a long time. Well it had a new airtex fuel pump on it and the guy I bought it from said the tank had been cleaned 3 months earlier. Read bad reviews about airtex. I knew it was running lean because of the intake pop. So I bought a MSD fuel pump to install. Well when I took off the airtex guess what I found ?? a chunk of rust caught in the fuel pump nozzle. Obviously they changed the fuel pump BEFORE cleaning the tank!! New pump and rust dug out helped a lot. But as soon as it cools off enough I intend to remove and clean and reline the fuel tank. At the same time I will remove and clean fuel dampener and blow the lines while dampener is off (it acts as a flow stopper to tank). I too cleaned every thing from fuel filter to injectors and thought I was safe, but on 35 year old cars, got to think fuel tank to injectors. Rust catches in the darnest places. just a thought ...hope it helps Great tip about cranking idle screw down to see if it dies, checking for vacuum leak. love my Z Rich

Greetings all I have a stock 75 280z. Electronic ignition. When I try to use my digital multimeter (set to 6 cylinder) to set my rpm. After I connect ONE meter wire to the coil I get a rpm reading but as soon as I hook the other to a ground, the meter zeros out. If I hold it close to coil I get a reading, but as soon as it touches metal it goes to zero.Reading varies by how close I hold meter ground wire to coil or metal. Doesn't seem to make a difference on what meter wire configuration I use. Been fixing cars for 40 years never ran across this before, searched google, searched here and other z sites. Must not be using right search phrase. I'm stumped! any ideas why it's doing that? Sorry if I am not clear enough, or you need more info just ask. thanks for taking the time to read this. PS tried it with analog meter same results Rich