my 92 f150 5.0l stumlbles under light load say a hill or against the wind. I pulled the vacuum hose off the egr and there was no vaccuum even when I rev the engine. So then I checked at the egr soliniod and the is vaccuum at one hose but not the other which tell me the soliniod is bad. I replaced it with a new one but still the same symtoms, so now I wondering about the power side of the egr soliniod. Mine has two wires the one has 12 volts and the other one seem to incease and decrease the voltage but no vaccuum will though the solinoid can someone shed some light on this problem.