Running on one rotor during startup only
 

I have a 1988 rx7 S4 with an '86 13bt. Upon startup, the front rotor (closest to transmission) isn't firing until about 30 seconds after starting. It often times won't start unless I hill start it. Primaries and secondaries are pumping fuel, cleaned the spark plugs, sensors are all plugged in tightly and it runs perfectly once the second rotor kicks in. Any ideas?
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the front rotor is at the front of the car. rotor at trans is rear(#2) rotor. but issue could be a sticking seal. possibly due to carbon buildup. run some sea foam thru the fuel system. maybe consider having the injectors cleaned and tested. any idea the mileage on that engine?

Good idea. It was rebuilt roughly 5000 miles ago (odometer doesn't work). It's bridgeported with 3mm seals btw

Just a heads up i do remember hearing that SeaFoam is no good for rotaries and will make the coolant seals swell

Seafoam has been used for decades on these cars and endorsed by numerous "gurus" on this forum...I think you might be mistaking it with a different cleaning product. It is recommended to ingest via the fuel system, not via the intake track like a piston engine.

why not do the right thing?