Help 1989 C4 - Car runs rough, stalls, sometime will not start just turns over. Fuel pressue at start up 41 and at running 39 lbs. Had it tow because it would not start. Got the car sprayed starting fluid in intake, started it up, ran for a few minutes died. Next waited a while did the pressure again, same read and bleed system and it started right back up. Now can give it gas without stalling but still runs rough at idle. Check engine light does not come or register any codes. Car has the original fuel pump, relay, EGR value and MAF Sensor. O2 sensor been changed. Car has 80,00o miles which 75,000 are highway miles. Any help would be appreciated. Has anyone had a problem like this?