OK fellow gearheads, I have a coworker a '94 5.7L and he is having strange EGR symptoms. At very low loads/thottle position, even in P/N, the PCM is showing 100% desired EGR, but 0% actual EGR. I was under the impression that the EGR was a proportional flow not just ON/OFF. Most, if not all top end sensors have been replaced, i.e. TPS, MAP, IAC, EGR solenoid, EGR valve. When I hooked up to it it showed 3 codes, High TPS, EGR, and Knock circuit, some or all may have been from who know when. I cleared all of them to see which ones are actually set when the rough running condition happens, but nothing showed up when it ocurred. I will post back shortly with the 'log. He got it to stay in the rough running condition for an extended time at around 6 minutes.
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