Hi all, my father-in-law and I have finally finished our conversion project (1990-745 B230F Rex -> B230FT LH), and the car runs great! ...but only under one condition: when I manually ground the black-yellow contact at the FI-System relay in the dash.

The contact point is listed in TP-31571/1 (the volvo wiring manual for this year) as a ground signal to the relay that is controlled by the ECU. When I manualy ground it the fuel pumps run and everything is happy with the world! But, without my intervention the pumps fire once during start-up and then do not get the FI relay signal that lets them run. It appears that the ECU is not allowing the ground to occurr...

I have heard that in the absence of certain sensor signals the ECU does not let the FI relay activate the fuel pumps, so that the pumps don't run when the engine is not running (a safety feature I suppose). But I don't know which signals would result in this effect...

Any suggestions? Or, any extra info I could give to prompt for any suggestions?

THANK YOU! (all caps since I am desparate:)
--
Two '98-S70s and One '90-745. My First Car: '74 244DL Gone But Remembered!