I put the bigger mustang fuel injectors in my 86 standard vette. I ran the car for about 3 hours driving, it never compensated for the new injectors, ran rough. Next time I started it it smoked under the car and in the vents but ran. Now it won't start. I checked fuel pressure, spark and injectors for fire with a light checker. All were fine. The key resistor has been bypassed. Any ideas?