I have a 1995 GMC Safari (it's my work van) It has a 4.3 V6. This is a high milage vehicle, but the engine seems to have plenty of power, starts fine and runs smooth. My problem is that once I get going, It developes a rough idle. It has new plugs, wires, cap, rotor, oil change with some treatment (i forget which?) and I have run gunk and chevron fuel system cleaners (in that order). I have also replaced the fuel filter. It was recommended to use BG44K Fuel conditioner, which I have yet to do, but I plan on it with my next fill up. Is there anything else I should look into? Thank you very much for any help, I am giving this van to my pregnant sister and her husband in a couple weeks and I want it to be "tip top" for them. Thanks again -Dylan

 

P.S. I had the Cat removed and got all new straight pipe with a new OEM muffler...