Hey guys, im doing an obd1 ls vtec swap into my 91 hatch and im having problems with my distributor. After cranking for 4 seconds it throws code 15 or igm code and stops pulsing injectors and has no spark. I bought a new distributor and im having the same problem again. I back probed the igp wire on the plug and there is no pulse while cranking, just a solid light. For my ecu im running a p28 with hondata 300v3. while cranking my voltage drops to 10.8V on a fully charged battery, maybe thats my problem?? My grounds are block to chassis, thermostat, battery negative to chassis and ecu to chassis. Im relatively new to cars so any help or conformation would be amazing.

 

10.8v isn’t bad for cranking voltage. I don’t think the problem is there.


I would double check your dizzy wiring. Also you are running a obd1 dizzy right? The obd0 (91) distributors send out a different rpm signal to the Ecu and won’t work on a obd1 Ecu.

 

K7-1Ktrevor is correct here... mostly. He misspoke when he said different RPM signals... but I knew what he meant to say. So here is the clarification:

The OBD-0 distributor has a CKP (Crank Position) wheel that pulses 16 times per revolution. OBD-1 and OBD-2 distributors have a CKP wheel that pulses 24 times per revolution. Your S300 equipped OBD-1 ECU is looking for 24 pulses per revolution to properly time the firing order, so if you do in fact have an OBD-0 distributor, the ECU and distributor don't jive.