cpt_gloval

iTrader: (1)

I have a newish issue where my 85 RX-7 with a Nikki carb leans out bad going up steep hills. I have a wideband so I can see it go to like 16 and cut out and it will putt-putt along struggling up the hill. Seems like one rotor is losing fuel? I checked the float windows and they both seem ok, fuel in the middle of both. Any advice?

t_g_farrell

iTrader: (1)

Fuel pump or filter or tank debris clogging supply line. Change the filter and then check fuel pump flow and pressure. If thats all in spec then drop the tank and see whats clogging it. Oh and also make sure the vent lines are working.

j9fd3s

iTrader: (3)

i had a car with a weak pump and it would do exactly this. i would change the fuel filter and then do a volume test and see where it is at.

to do the volume test you need some container with markings for level on the side, a stopwatch (phone), and on an 84-85 a piece of wire to jump the fuel pump relay.

you take the fuel line off of the carb and put it in your container. jump the fuel pump relay, its above the accelerator pedal. turn key to the on position, but don't start the engine, and start the timer. the stock pump should do more than 1400cc in a minute. depending on the size of the container you have (mine was supposed to be for juice) you might do only 30 seconds.

Jeff20B

iTrader: (13)

If you still have a stock pump in there, that's a big part of your problem. People would say these would run out at the top of 3rd gear on a stock carb with stock ports.

Carl

iTrader: (2)

If the stock pump is working properly, it should provide enough fuel. I raced with a stock pump for nearly 10 years with no problems. That was with stock port 12A and stock exhaust manifold. I didn't switch to Carter pump until I swapped to a header. Don't know if I needed to change the pump at that point, but I could so I did. I definitely agree with checking pump capacity, filter, and possible blockage of pickup in tank.

Carl