Irratic idling(4cyl auto)

[ashley]

O.k here we go again trying to get this thing fixed!I've prev posted this symptom before where after accelerating & letting off the gas to coast; the cars idle jump around. When the engine revs drop to approx 7 or 8 hundred the car will what it seams like, try to compensate by increasing the idle to where it should be.checked the following:plugs & wires,cap & rotor.fuel filter is new, maf sensor is good.is it possible a tps could be doing this?lucas fuel treatment was even added with no help.any help would be great

[terrastrife]

clean the IAC valve, fixed mine up fine

after 16 years of oil gunked on it, its time to be cleaned..

erm.. that is if you got one lol.

[ashley]

I finally got the chance to go out 7& fix it. There was used one I had kicking aroung from I think was a late 80's model, same engine & auto as well. I also cleaned the hell out of it with throttle body cleaner.Now installing it wasn't a problem, it was when I started the car! The idling was at approx 1500 rpm even after being warmed-up.I then took a look at what appears to be an adjusting screw of some sort facing upward.I adjusted it clockwise until it looked roughly at the same position as the old one.Only took about 2 full turns & the idling is now at about 1000 r.pm.& the car runs bettter then ever as the irratic idling as well as the extreme hesitation the car prev had.Now the big question: Is there another (proper) method of adjusting that screw that I should know about? &despite the fact that the two units(throttle bodies) are identical all the numbers are exactly the same except for a few characters.

[terrastrife]

someone probably cranked it upwards b4 your time to fix an idling problem (bandaid fix).. it really should be left in its original position

[ashley]

Would this have any effect on gas consumption?

[Toyteq]

Set the timing and the idle mixture together. 8-10 base timing jumping the diag connector(cutting out the computer) , idle should be around 850-900 in neutral.