Fast idle and hard starting cold 1984

[Heyblue]

Hi all; 1984
Here is my next fault to fix. Actually this problem popped up after repairing broken wire going to temperature sensor (gauge was reading 299 F), so my first thought was maybe I knocked something loose, but haven't found it yet.
Engine turning over but not starting when cold. Poured a little gas in one of the throttle bodies. Started but idle is very high 1800-2000. I waited until came up to temp. to see if it would settle down, also checking the temp. gauge. Now turning off and back on it always idles high. Before this problem started it use to occasionally alternate between to low to too high then settle. Reading the FSM tells me the idle air control valve alters amount of air which will bypass the closed (at no throttle) butterfly to regulate idle speed. I pulled one of the two out and it seemed quite dirty. I am leaning towards replacing it (them), but there are two and min. $80 each, so not having a winning lottery ticket yet am looking at all ideas before just tossing money at the problem.
Question one, can stuck open IAC's make that much difference in idle? Two, would this explain hard starting? Three, what is the best cleaner to spray into the body after removing the IAC's?
OK #4 any other ideas?
Thanks

 

[djsroknrol]

Sounds like your throttle positioning sensor is going south or already gone

On a DVOM, it should read .525 +/- .075 at closed throttle across the middle and bottom leads on the TPS.....They're very easy to replace; just 2 screws

 

[Heyblue]

thanks for your reply, however;
As you can see my original post was back on the third of this month, so I keep diagnosing and what I found. The IAC's (idle air control) were gummed up and staying too open. I replaced one and cleaned another. Also the car's computer recalculates the starting point on these after running at about 40 MPH, which I did. These two things fixed the problem. Also, on hard starting, I read in the Service Manual that if you give any throttle the computer thinks the car may be flooded and shuts off gas flow. That may have been my problem on hard starting.
Hope my experience helps anyone with similar problems.