86 rx7 wont start was running beautifully one second then went to start again and jusy cranks. Compression at 75 on each rotor and has 3 perfect bumps of 45 psi on each rotor. Not flooding. Getting fuel rail pressure. Getting spark. I dont understand

 

Update. Alternator was seized guessing not providing enough for the car to start. Bump started it and it started then the belt started to smoke good times lol

 

that compression number is low too.

 

The why does it run just fine

 

Because the engine is currently doing you a favor. Also, a low compression engine can often be difficult to start.

 

This was also a cold compression test too does that effect anything? And my peaks in compression for each seal were over the recommended amount. Also my compression tester is old and might be reading low seeing as ive gotten lower numbers than expected on even the most brand new engines

 

Compression testers rarely get out've adjustment unless they have been knocked around

 

This one is verryyy old. I dont know what its been through haha and the car starts up easily and revs good and is decently quick so im happy