Gearheadlevi

I have a 1981 RX7 which has been sitting since I bought it 3 years ago, every few months I would start it up and it Idled fine but never drove it because it had been wrecked.

6 months ago i stopped being able to idle it for very long, I suspected the battery or fuel. I have had the batter checked at auto-zone and they said it is still good.

After cleaning out the fuel tank, blowing out fuel lines and put some fresh fuel in somehow the wires were broken off the aftermarket fuel pump so I replaced it with a cheap one off amazon. The car still wont run right with the new fuel pump and am wondering if it is putting out enough fuel pressure/flow.

Someone recommended I test the pressure and compare to spec, could fuel pressure really be an issue though? The fuel pump I just installed is 12v 1-2a 42gph 2-3.5p.s.i. Shut-off pressure. I am thinking more likely I have a gummed up carburetor or maybe an electrical issue, the fuel tank had ethanol gas in it with stabilizer but it had a little crud.

My fuel pump doesn't ever shut off is that normal, I figure it is since there is a return line running from carburetor to tank.


The rotary will someday make a big comeback,
-Levi.

j9fd3s

iTrader: (3)

if its just idling i kind of doubt its the fuel pump, but its very easy to test it.

you need a stop watch, and some container with markings on the side. i have something that was supposed to be for juice, and its marked in cc.

the spec is more than 1,000cc/min, which is 1 liter, so if you only have a 1 liter container, do the test for 30 seconds.

remove fuel line from carb, put it in container, turn the key to the on position for 30 seconds to 1 minute, and see how much fuel you get. if its close, maybe it needs a fuel filter, or check the voltage at the pump

test #2, you need a pressure gauge. put it on the fuel line and turn the key on, the manual says 3.7-4.7psi, lower than that, or unstable is bad.

and you're done!

7aull

iTrader: (2)

Have you changed the FUEL FILTER? Even if you did recently and have been cleaning the tank, gunk could sill be coming thru and plugging it. Change it again.


Stu A
80GS
AZ

midnight mechanic

maybe it is a clogged jet, and you can try some kind of injector cleaner, or sea foam?

Benjamin4456

If you can see the float bowl glasses that would the first thing I'd check. There are two and they are located on opposite sides of the carburetor (front and back with respect to the car). When running fuel should be about halfway up the glasses - you'll likely need a mirror and maybe a flashlight to see the one on the firewall side. If it's halfway up the glasses fuel pressure isn't your idling issue.

Gearheadlevi

Car is now running fine now,
I didn't really do really anything except put sea foam in carb try to run it about a month ago.

Today it fired up after cranking for 2 seconds and after a few minutes idled nicely around 1k rpm. I wonder if having lubricant in the sitting for a month in the carb or engine helped in some way, the weather has also been about 20 degrees warmer (80°F today) so I'm sure that would make a difference.

I did check the flow per j9fd3s instructions and it is 1.5L a minnute which is more than enough.

Benjamin4456 - Good to know about the float bowl glasses, I will locate for future reference.