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Discussion Starter #1
so i just replaced my TPS and when i hooked the battery up and started it, it had a high idle. i dont have a tach but my guess it was right around 1200rpms. it seems after running it for a while its came back down to normal but still not sure if its quite right (truck has been driven a few times since the new sensor). well in trying to figure out what was wrong i unplugged my IAC and got no change at idle. ran the same whether it was plugged in or not. So guys give me ideas on what it might be.

Thanx,
Bill
 

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yo!
Has it been scanned for Codes yet?
Get it done for free @ a local parts store.

run it around to heat the engine up and shift thru all gears incl Reverse.
then; turn off all accesories/lights, etc.

Do KOEO portion first

For Key On Engine Running (KOER) portion, the engine has to be still @ normal operating temp.

Post any codes found here or look em up in my broncolinks.com site
such as;

P1506/ P1507 Idle Air Control Overspeed Error
Idle Air Control Underspeed Error
A vacuum leak, a damaged IAC assembly, a stuck IAC valve or throttle valve typically sets one or both of these codes. The IAC can be checked with a scan tool, sensor tester or multimeter. A vacuum leak is one of the most common causes and can be checked with a vacuum pump.
by tradervar.com
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Idle or Noise Problems & Troubleshooting; including HIGH IDLE Conditions; "...For high idle problems, try unplugging the IAC motor. If the idle drops, its usually due to an input signal to the computer which results in the computer raising the idle speed. If this is the case, look at all of the computer inputs to make sure everything is up to par. If the engine RPM does not drop when the IAC motor is disconnected, then either the IAC motor is not functioning properly, or, there is a vacuum leak in the engine. Stop the engine, remove the IAC motor and block off the passages. Restart the engine to see if there is any change in engine RPM. An idle speed higher than base idle specs indicates a vacuum leak. If the engine RPM is at base idle specs, then the IAC motor is bad. Resistance specs are 7-13 ohms. A good resistance reading does not necessarily mean that the IAC motor is good. Occasionally, an IAC motor will become weak, and will actually bypass too much air, causing a high idle condition even though everything else is operating properly..." READ MORE
Source: by Mike N via Joe D at http://web.archive.org/web/20030411...m/techbulletins/engine_controls/tt3q00.CQ.pdf
It is via web.archive.org, so it may take awhile to load.

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High Idle & Dieseling Troubleshooting Chart in a 94, from PCED Chart 7 for a 94; Preliminary Checks; Vacuum Leaks, Throttle Plate & Linkage, Speed Control Chain Binding/Sticking, Air Intake Tube/ Intake Manifold Leaks..." READ MORE
Source: by Ford via Steve83 (Steve, That dirty old truck) at http://www.supermotors.net/registry/media/797515
This list vac leaks as a primary check; To use the ts procedures shown, y.You would need an OFFICIAL Ford Bronco Electrical and Vacuum Troubleshooting Manual (EVTM), Powertrain Controls and Emission Diagnosis Manual (PCED), Service Manual CD from Steve83 (search for him here and contact him by the e mail function. or E Bay... Best under $25.00 thing you'll ever buy for repairs/ts.. if you have trouble w/da e mail function here; let me know

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And since you know hiow to do that inital test you prob saw this;
Overview & Testing; "First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I’ve had the torture of learning throughout the years: Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller •Inlet Air Bypass •Intake Air Bypass •Intake Air Control..."
Source: by Ryan M (Fireguy50) at http://fordfuelinjection.com/index.php?p=39
 

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Discussion Starter #3
thanx miesk, but why would it all the sudden flip out right after i put the new tps on? im goin to scan it and do the vacuum test on it and see if its leakin anywhere tonight.
 

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yo, dunno, unless the TPS was made in Chi..... which would cause that since some of the Chin.. parts are pure crap.
I use Motorcraft... and I buy on-line via Troy Ford at Amazon; http://www.amazon.com/s?ie=UTF8&rh=n:15684181,p_6:A18G8GVWHHIMY9&page=1

I bought a MC DPFE & IAC sensor; both were 1/3 of any local Ford dealer price w/Free shipping and no state sales tax... saved over $200.00 plus tax on both, total
 

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Discussion Starter #5
Ok well the problem is still there. Its throwin codes but nothing that wasn't there before i did the tps swap. Also changed out the throttle body gasket thinkin it might be suckin air but no change. The voltage at my tps is .96 so that's within spec. I have no idea here guys
 

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I'd pull the IAC off and clean it just for kicks. It's easy to do, probably needs to be done anyway, and *might* be the source of your troubles.
 

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Discussion Starter #10
Its givin me a code for my secondary air injection, one because there's no guts in the cat, and after a while one for the crank position sensor because one of the ears is busted off the pickup and I can't find a new one.
 
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