Raydarlov
12-17-2004, 04:24 PM
I have a 4.3 liter V6 in a 1991 Astro van. It has 262,000 miles on it. The engine has always run smooth and smoke free. Right now the engine stills seems sound, with only a brief puff of white smoke at startup. But it had developed a rough idle over the past year. Kinda like it had an inconsistant miss or two going on. But as long as you were just cruising down the road, or during acceleration, the engine always felt smooth as silk, no noticable misses, and the power was there. It will still lay rubber!!!
So I did a tuneup. I didn't tweak anything. Just changed normal things like plugs, cap, wires, rotor button, air cleaner, and oxygen sensor. After the tune up it did run smoother with more power as you would expect, but there was no change in the rough idle part of it.
So it was really cold this morning for the first time this year. I started it up, and of course the choke is licked in like it should be and the RPM's are up (don't have a tach). It hadn't warmed up yet when I decided to go ahead and go. I put it in gear and the engine lugged down, the engine felt smoooooooth. There was not a hint of a miss. Now that's the way it's supposed to feel when you put it in gear. But when the engine warmed up the rough idle returned. Of course the choke is off now.
Someone suggested it's a timing issue. Do they even have a place to adjust just the idle on fuel injected engines? I thought maybe it could be a dirty fuel filter. Is there faulty sensor somewhere?
So I did a tuneup. I didn't tweak anything. Just changed normal things like plugs, cap, wires, rotor button, air cleaner, and oxygen sensor. After the tune up it did run smoother with more power as you would expect, but there was no change in the rough idle part of it.
So it was really cold this morning for the first time this year. I started it up, and of course the choke is licked in like it should be and the RPM's are up (don't have a tach). It hadn't warmed up yet when I decided to go ahead and go. I put it in gear and the engine lugged down, the engine felt smoooooooth. There was not a hint of a miss. Now that's the way it's supposed to feel when you put it in gear. But when the engine warmed up the rough idle returned. Of course the choke is off now.
Someone suggested it's a timing issue. Do they even have a place to adjust just the idle on fuel injected engines? I thought maybe it could be a dirty fuel filter. Is there faulty sensor somewhere?