I have a stock 1989 of of z28 I am trouble with it starting I can start it but runs rough no power I have replaced the coil cap rotor plugs and wires pick up coil I can start it drive it then like no spark sometimes I can shoot starting fluid in and it will start I have good fuel pressure i have checked the injectors I am at a loss

 

Where is the base ignition timing set? When checking this and bypassing the EST, does the timing move drastically once the EST is reactivated?

 

Are the fuel injectors original? If they are they are probably bad, 1989 was a bad year for fuel injectors in these cars.

A quick check is to unplug them and measure the resistance of each one. They all should be around 11 to 15 ohms. Typically they short out and measure low ohms and cause the problem you described.

 

I had a similar issue. try a fuel pressure drop test. I had good pressure but my pump wound up being bad.

 

actually the injectors from 1985-1992. The biggest problem with them is the coil. We normally say anything less than 12ohms is an indicator that the coil is starting to go bad. The coils typically cause problems when the injectors are hot.

 

My friend overheated his '88 Corvette once and took out half his injectors!

 

 

lol