Blown EGI Fuse, Won't start
 

I have a 90 Rx7Conv no turbo. Lost spark getting on the freeway. No engine light. I placed a new 30A EGI fuse and saw the engine light for 5 seconds then the fuse blew again. I currently have a wiring diagram manual on order. I rebuilt the motor 1 yr ago/15K mi ago. Wondering if anyone knows where the wiring for this fuse could be affected in a rebuild or just any info period. Help plz.

Check your grounds.

Well fuses blow when there is a short. You won't be able to put a new fuse in and have it not blow on you until you find the short.

If you can, follow the wiring from the EGI fuse. You might be able to find the problem doing that. Then again, you might not be able to.

I would check the FSM for a wiring diagram and use a DVOM to try and find the problem.

Every solenoid on the engine has a Black/white wire. Take a look at any of them and one of the two wires on them is ....Black/White. It is fed from the 30A fuse. The 30A fuse feeds to the Main Relay and leaves the Main Relay on a ....Black/White wire. It also feeds a pin on the ECU but the ECU is the LAST place I'd look for it being shorted. See the FSM wiring schematic.

Check the two solenoids on the acv first.

mine kept blowing and it ended up being one of the wires going to a selonoids on the vac rac shorting out on the engine. taped this piece off and fixed my problem.

I had a similar expierence and it was the wire bundle behind the altenator was held in place with a metal clip. Engine vibration caused chaffing on the bundle and wore through enough insulation to cause a ground. Just put some electrical tape around it and everything has worked since.

Thanks for the good advise, waiting for the wiring diagram fsm I ordered, untill then I can start getting my fingers dirty with your help. I'll let you know if I find anything.

I think I found the trouble. I found a black/white wire under the upper radiator hose. There is three bolts holding the thermostat cover for the hose. There is a black 2 wire connector and a White 2 wire connector. I saw a black arc mark on the bolt and the black/white wire on the black connector was touching that inside bolt. I want to test the whole circuit to make sure it is good before replacing the fuse. I hope you can help me with this as I havn't recieved my wiring diagram FSM yet. I can't wait to fire the wankel up again. Man I miss that sound.

She's a running. I do want to test the whole circuit if someone can guide me. Thanks.