90 TB idle surge

[Motohead1]

Ok my 90 Throtlebody is surging bad but only if the car is moving as soon as i come to a stop the thing settals down and sits on a rock solid 750rpm. I just took the TB off today to replace a what seems to be perfectly good IAC motor. Just to see if it would help. so i decided to tearit all apart and see if i could make a plate for bypassing the cold start warmup. but there seems to be no wax pelet type in a 90 throttle body. Instead theres a mechanisim with two oposing springs and a pintal that looks like it might move like a thermostate. its all held in with a plug thats adjustable by alot. meaning i can change the tension on the thing by almost a 1/4 inch in either direction. were should it sit? i caint find an adjustment for it in the manual?
thanks

 

[Motohead1]

ok heres the fix if anyone cares. i took a wild gess and cranked the plug all the way in so that the plunger was fully seated. this perty much elimnated the warmup function and closed the pluger fully. since the warmup function was now usless i disconected the water lines. put it all back together and fired it up it was holding 1200 rpm steddy. even after warm so i set the idle by grounding #10 and adjusting with the BISS. I set my idle at 850 and thats where it is all the time now. perfect for still using AC and not to high. it also most importantly dosent idle surge when rolling. holds the idle rock steady.


heres a few words for searches

VSS, Surge, warm up, Bypass, Plunger

 

[tallguy]

My car is doing the same thing, but this is all very confusing. Can you elaborate more on a IAC motor, and how to replace it? Where it is? Also, where is your warm up plate?

 

[Motohead1]

you have a 92 so it will be difrent IAC than mine but actually not as hard to replace. its held by 2 screws and has a plug in the back it looks round. it controls idle. but there are many other factors that can cause surge do a search and try those first.

 

[Emptytoys]

I have a 90 also but my surge is only when the car is "warm". It is fine when it is cold as in first thing in the morning, and then it is fine after the car has fully warmed up. But inbetween, it surges. Also if the car has sat for about an hour or so, not fully cooled down, it will not want to idle, I have to rev it for a bit, once it is driven it is fine.
Do you think that this may be the IAC also??

Matt

 

[Motohead1]

Its kinda hard to diognose o the internet but i can tell ya if ya have a 90 TB look at the plug behind the 3 screw plate as i mentioned above.