I have a 90 crx si. I swapped a b18a1 into it a few months ago I daily the car. Yesterday I pulled it apart to go obd1 (dizzy,ecu,intake mani,injectors, throttle body) used jumpers for the ecu and dizzy. It starts up but throws a cel code 4. It won't rev over 3500rpm. I've tried known good dizzy, ecu, jumpers. I've checked all wiring. Checked timing. Reset ecu. I'm stumped. Anyone have this problem or know how to fix it? I've spent a lot of time trying to find an answer before making a post. Please help

 

99% of the time it is wiring. Start by actually probing wires to verify they go to the correct locations from the distributor to the ECU.

 

yeah you need to do continuity tests on all your distributor wires and also make sure there's no shorts to ground. otherwise change your dizzy, then change the ecu. there's nothing else it can be.

 

this. grab a multimeter and test continuity for your wires from the ecu to CKP sensor in the distributor, and CKP to ground. also im pretty sure the ECU to CKP wire is shielded from the factory...