My 13b carby rx7 takes about 15 seconds of cranking to start. While I'm trying to start it up, I pump the accelerator a few times every 4 seconds. Once I have warmed it up I can start it up easily with 2 pumps of accelerator. I have only changed the spark plugs to see if that did anything. What the hell is going on?

 

- Take a compression test.

- Check fuel pressure.

- Check charging system / battery.

Start from there.

 

mine does about the same thing. i don't do 15 continuous seconds though.. 2 pumps, crank.. pump, crank... pump, crank, vroom.....

 

Sounds like a choke problem to me. Try taking your air cleaner off, have someone crank it when cold, cover the intake with your hand momentarily and remove hand. If it immediately starts - your chokes not choking.