throttle position sensor replacement tips
Member
Joined: Jan 2011
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From: Philadelphia, PA
Yes i've disconnected the battery. I just changed it to .6volt. Waiting on reset time taylor windows philadelphia windows for computer. Ive also have fresh fuel because i replaced both tanks and the fuel filter. New air filter as well. Headers and dual exhaust. Symptoms didnt get worse till i did the cel and started workin on throttle body.
OK -- perhaps this will help... but it might not...
did you check for vacum leaks? On the throttle body there is a little vaccume nipple/hose on the left side right between the two barrels... the first time I went to mess with the TB I unknowingly undid this connection which after 18 years is just a loose fit so its easy to fall off...
anyway when I went to start he car I got this see-saw idle...
probably not it, but who knows im just puttin stuff out there for you...
Senior Member
Joined: Aug 2010
Posts: 959
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From: Belmont, Ms
which manual do you have? mine is #26664 in the upper right corner of the cover, the tps chart is on p 4-21. It is possible to install the tps sensor rotated some amount so it sends an incorrect voltage. My manual stresses that if the sensor needs to be adjusted to rotate it ONLY in the clockwise direction. Unfortunately it doesn't specify a frame of reference so that's not super helpful. but that might be what's going on here.
I believe what the manual is saying is when you slide the tangs of the sensor over the throttle shaft the sensor can only be rotated clockwise to the installed position. If you rotate it counter clockwise it might result in a high idle speed on the 5.0 & 5.8 engines.
And the plug needs to be toward the IAC valve on these engines also.
Thread Starter
Member
Joined: Jan 2011
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I changed the idle on the tps to .6volts disconnected the battery for 45min and tried it again. Still not a smooth idle and no power when driving. I will check for vaccum leaks. I also tried disconnecting the new iac to see what that did. Only difference was a lower (500rpm) unsteady idle.
Señor Member
Joined: Sep 2010
Posts: 1,509
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From: Springfield, OH
your symptoms are consistent with mine when I was having IAC troubles. but it also sounds like you might have a leak in a gasket or vacuum line. I have heard you can get a can of starter fluid and spray it around suspicious gaskets and lines to check for leaks. Any leaks will suck in the starter fluid and cause the engine to rev up a bit (I think)
Senior Member
Joined: Jul 2008
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From: Long Beach Calimexifornia
Or a propane torch, unlit & set to a low flow.
Thread Starter
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Joined: Jan 2011
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Ok. Ive messed with it all day. Im going to just replace all the vaccum lines next. Prolly need it anyway and im getting annoyed with the tb. Its cold here in Va and i havent built that garage yet...plans are drawn...getting price estimate for everything now
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Joined: Jan 2011
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From: Philadelphia, PA
If you gotta camera post up a short video on youtube and link it here... helps to hear the problem on the video... somone might be able to help you...
Junior Member
Joined: Nov 2010
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From: Marysville WA
not sure where he read about .6v. every recommendation i've seen for fords calls for .95v to .99v, and i've worked on many many. your issue sounds to me like a idle air control solenoid. there are two styles available for 90's trucks, make sure you have the right one. happened to me once, got the wrong one and my idle was never stable until i installed the correct one
Thread Starter
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But if i unplug the iac it should idle correctly just not in the right idle range rpm right? Im headed outside now to change the tps back to .97volts now. The other code i got was 63 which if i recall right may be the egr not opening or the sensor gone bad. I'll check that out too.