I just replaced both my fuel pumps and if they have a check valve, they're built into the pump and screw in the front. I have replaced everything on earth except for EHA, Fuel Distributor and Cold Start Valve which I never need here in So Cal. Put new seals and injectors in today as well as a new fuel filter and had just put in a new fuel Acumulator. OVP is new. I could shove the old one back in there and see if it makes a diff. Not sure what to try next. Once she starts...no problems and idles perfect.

Tonight I took off my EHA Valve and adjusted it CCW 1/2 turn vs. CW from original setting after I took it off (only after I did 1/2 CW and caused engine to bog down and stall). It started up very quickly after having been warm but a noticeable difference. I'm thinking someone may have tried the CW adjustment long before I had the car and I just made it worse before by trying the CW adjustment. I had no visible leaks while engine was running or after I stopped it. You may want to try 1/4 turns CCW and see if it helps. Our cars may be trying to start too rich...any thoughts out there?