throttle body clean high idle

hey guys, so ihad this surging idle and i clean my iac valce and that solved that but i started idling high, around 1500 at start up and then around 1100-1200. it would sometimes settle to 800 but then go up. also when the car warms up and i shift my rpms will hang for a little bid.

well i did some research and decided to take off the throttle body and clean that it was pretty black on the inside so i used some throttle body cleaner. i got a new gasket and put it on. i disconnected the batter to reset everthing but when is start it up it will idle around 2000 rpms. what do you guys think the problem is. i let it run for a little and it only went down to maybe 1800-1900. also when i first started it i think coolant was coming out of the throttle body but that stopped.

I am new to this and would really apreciate some help. my idle being this high makes me nervous and i definitely need to get it down. i have an 87 mustang gt, 5speed
 
Start up the engine, pull the spout connector and unplug the iac. Locate the idle screw under the throttle body and adjust the idle to 600-800 rpm. If the engine stalls, open the idle screw up and restart. Back the screw off to get proper idle.

Disconnect the battery and while it sits, reconnect the iac and put the spout back in. Hook the battery back up.

Check tps voltage and verify tps is between 0.5 and 1.1 volts. If it is between that range, you are fine. No need for that .99999 voltage bs.

Start can and let it idle. Might take a few mins but it should settle out to idle. Turn on all the accessories and let it idle for a few mins. After a few driving cycles it should be steady.

If not....run the check engine codes. Look for codes pertaining to the tps, ect and iac.
 
thanks for the quick reply. just for clarification is the spout on top of the iac and connected with 2 philips head screws, the section that the plug goes into? also on the idle screw, will turning it left bring the idle down?

thanks again for all the help!!!!!!
 
No, the tps is on top of the throttle body with the two screws.

The spout connector is on the wiring harness going to the distributor. It looks like a square plug you can just pull out of the socket.

On idle screw....screwing it in will raise idle. Backing it out will lower it.

Usually, I screw it in to bump idle, and then I unplug the iac and the spout and then bring idle down.
 
sweet thanks for explaing.

so when i first put the throttle body back on with the new gasket, i started the car up at first and i think some atifreeze was coming out of the bottome of the throttle body onto the valve cover and it was smoking. it did that for a little and then it stopped.

do you thinjk the gasket was not sealed at first but then it sealed?

thanks again!!!!!!
 
See the "Surging Idle Checklist” for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.
 
ok, so i did as mustang5l5 stated above and my idle did go down but i was distracted as a bunch of white smoke was pouring out my exhaust.

is this normal when you take the throttle body off to clean it and then reinstall it? my car has never poured out white smoke before.

please help.

Thanks
 
ok i put a new gasket on and it seems sealed up pretty good but i notieced that my iac valve is not sitting against the throttle body well because the bolt hole is stripped. so only one bolt tigtens it.

so, i am still idling high (around 1700) and i can hear a lot whining coming from that area so would that cause my idle to still be around 1700? and to fix the iac do i need to get a whole new throttle body for it to screw into?

thanks for all the help.
 
As you noted, repair the stripped hole.

For diagnostics, I suppose you could try using some RTC (Really Tacky Chewing-gum - an idea from Jrichker), where you seal the area with used chewing gum.
 
thanks hissin, i might try that.

i was doing some research on the tps and my tps sensor seems different. mine is completey flat on top with the 2 philips head screws on the sides. when i google the piece it seems that iit is lifted a little with multiple screw holes and it seems that would be how you adjust it, see link please.

Duralast/Throttle Position Sensor (TPS213) | Throttle Position Sensor | 1987 Ford Mustang 8 Cylinders E 5.0L FI HP | AutoZone.com


does it seem that i have the wrong tps sensor because mine does not look like this and i can not figure out how to adust it?

thanks again and sorry for all the question.

you guys are rock!!!!!!!!!
 
thanks hissin, i might try that.

i was doing some research on the tps and my tps sensor seems different. mine is completey flat on top with the 2 philips head screws on the sides. when i google the piece it seems that iit is lifted a little with multiple screw holes and it seems that would be how you adjust it, see link please.

Duralast/Throttle Position Sensor (TPS213) | Throttle Position Sensor | 1987 Ford Mustang 8 Cylinders E 5.0L FI HP | AutoZone.com


does it seem that i have the wrong tps sensor because mine does not look like this and i can not figure out how to adust it?

thanks again and sorry for all the question.

you guys are rock!!!!!!!!!


The photo is upside down. What they are showing as the top is really the bottom. I wouldn't worry...guarantee yours is right
 
TPS_IAB_Pic.webp



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