Krazy1

Hi all, I recently purchased 2 1979 280zx cars. 1 is for a restoration and the other is a parts car. I have the build running decent but I am experiencing a popping through the intake or breather. Here is what I have done so far:

New plugs, distributor, and wires.
New fuel filter.
New fuel pressure regulator.
Confirmed fuel pump pressure.
Replaced dry rotted vacuum lines.

Car has 55,500 miles on it. It will scream at around 3,200 RPM's and up, but if it drops bellow that it bucks and pops. I have pulled the AMF and followed a link to clean and repair. It looks brand new under the cover with no grooves. I am waiting on the repair manual I ordered so any help would be greatly appreciated.

PredatorZ

Here is a link to a downloadable FSM

XenonS130 - S130 Reference

rogerz

have you done the propane test for vacuum leaks which are the bane of an FI engine. unmetered air into the combustiion chamber throws everything off. did you check ignitiion timing. AMF is the outfit that bought Harley I think. you probably meant AFM air flow meter. pull the oil filler cap when hot and idling. if she runs worse - good probably no massive vac leaks. if it runs just the same then you got a vacuum leak to find and fix.

Krazy1

Great advice, thanks!

Krazy1

Went dead when I pulled the oil cap!!

rogerz

probably good but only a quick and dirty check. still lots of other things to examine

FricFrac

Poping through the intake makes me think the A/F is off. Check the AFM - a rebuild is a good idea and easy to do. Looking at the tracks isn't the proper way to check them - use a meter and the FSM to make sure it's within spec. Check the connectors as well. I always replace them on a new to me car.