Ultimate Throttle Position Sensor (TPS) Thread - FSB Forums
Register Home Forums Active Topics Photo Gallery All Albums Mark Forums Read Auto EscrowInsurance FSB Store
FullsizeBronco.com is the premier Ford Bronco Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Display Modes
Old 11-21-2005, 10:17 AM   #1
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
Ultimate Throttle Position Sensor (TPS) Thread

PROBLEM: A number of months ago I discovered that my 86 Ford Full-size would hesitate/buck after about 10-15 minutes when the engine was at operating temperature. It would idle smooth and run fine until it hit 2000-2500 rpms...cruising speed.

So after reading many threads, I decided that the truck needed a tune-up. So I replaced cap and rotor with MSD, plugs, plug wires (Ford 9 mm) and even decided to go with a higher performing coil (Accel Supercoil). I also did the Seafoam thing (see my write up). It ran smoother but I would still get the hesitation/bucking.

BACK TO THE DRAWING BOARD: Started reading more threads on TPS, IAC and MAP. Decided to clean the IAC...someone on here had a great write up...search if your are interested. No change..smoother idle though!

DIAGNOSIS: Decided it must be TPS...yeah I know...look for codes. This time I did not have too! See below if you even suspect you have a TPS issue. There is a voltage test you can perform to determine if the TPS is within normal oerating ranges.

First you will need to locate the TPS and plug. The TPS is located on the end of the throttle shaft on the throttle body (TB). By monitoring the output voltge from the TPS, the PCM can determine fuel delivery based on the throttle valve angle. A broken or loose TPS can casue intermittent bursts of fuel from the injector and/or an unstable idle. Any problems with the TPS will throw codes 23, 53 or 63 for the two digit system or 122 through 125 for the three digit code system.

TO CHECK THE TPS: Turn the ignition to ON (engine not running) and install the probes of the volt-meter into the ground wire (black) and the signal wire (green) on the backside of the electrical connector. This process is called BACKPROBING. Turn your key to the on position (the engine need not be running to perform this test). Your meter should read 0.50-1.0 volts at idle. FYI...because the black probe kept on sliping out of the back of the plug I grounded it to the battery, which works just fine aso.



Rotate the throttle to the full-open position and the sensor should increase voltage to 4.0-5.0 volts. The maximum voltage I got was 1.85 volts. So I was for sure this must be the problem. Many have said that if you do not get a steady increase in voltage, this also is a sign of a bad TPS.

THROTTLE BODY REMOVAL: In most case you will need to remove the TB to get to the TPS. First remove intake hoses and the throttle cable assembly.


The bolts that hold the throttle assembly (located on top of the intake) are 1/2"


Next disconnect IAC plug, coolant hoses and vacuum lines. Remove the four bolts holding the TB to the intake. These bolts are 3/8".




This is the bottom of the TB where the TPS is located


While you have this apart...check the intake and TB for crud build-up

Mine was looking pretty nasty. Get some of this, a toothbrush and a rag and start cleaning it out:


CLEAN TB AND INTAKE:



Here is the new sensor to be installed...normal pracie was $54.99 my cost was $34.50, comes with a life-time warranty. While I was at it I decided to pick up a NEW Haynes manual. By the time it was all said and done I got the sensor and manual for original price of the sensor...christmas has come early!



INSTALL: Prior to removing the TPS, remove the negative battery cable. Some truck years will require that you scribe a mark across the sensor and the TB to ensure that the new sensor is installed in the same exact location. I was not sure about my truck so I did it anyway.


Remove the two phillips head screws and remove the sensor.


New sensor should be positioned the same as the old...wiring harness pointed away from the IAC. Engage the tanges of the sensor with the throttle shaft blade, then rotate it clockwise to align the reference marks before installing the screws.


Reinstall the TB in reverse order. Make sure you hook vac lines, coolant lines and sensor wires up.

FordFuelInjection.com has a great article on TPS. Please link to Fireguy's site for more information. Hopefully I have not left anything out. I'm sure you will let me know if I did! Good luck!
Xris is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 11-21-2005, 03:43 PM   #2
welndmn
Well Done Man!
 
welndmn's Avatar
 
Join Date: Feb 2003
Location: Brentwood, CA (East bay area)
Posts: 1,657
iTrader: (1)
You need to make sure with the throttle closed you are just under 1 volt when you install the new one to.
__________________
Mark
71 BKO 42 inch balloons.
http://www.wildhorses4x4.com/
welndmn is offline   Reply With Quote
Old 12-01-2005, 02:38 AM   #3
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
Wow what a great thread! I have an 86 and I just figured out where the TPS is. I want to replace mine because I don't know how old it is but it sounds like you need to align the TB and TPS to function correctly not just replace the TPS, is that about it? I don't see a gasket on your TB is there supposed to be one?
Also, what type of metal is the TB made of, my cooling tubes are rusted. I want to know if these tubes are pressed in and can they be replaced or can I drill/tap in some threads and make them removable? Thanks!
JKossarides is offline   Reply With Quote
Old 12-01-2005, 07:48 AM   #4
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
Quote:
Originally Posted by JKossarides
Wow what a great thread! I have an 86 and I just figured out where the TPS is. I want to replace mine because I don't know how old it is but it sounds like you need to align the TB and TPS to function correctly not just replace the TPS, is that about it? I don't see a gasket on your TB is there supposed to be one?
Also, what type of metal is the TB made of, my cooling tubes are rusted. I want to know if these tubes are pressed in and can they be replaced or can I drill/tape in some threads and make them removable? Thanks!
1) 10th picture (after the spray cleaner) showsd the TB gasket. take it off before you clean the TB.
2) I beleive some models you have to align correctly...nt sure if the 86 is for sure but I followed the directions just in case (marking the position)
3) I think the TB is made of cast aluminum
4) The cooling tubes are not aluminum...from the looks of my pics maybe they will screw out or gently pull out??? Maybe someone else has an answer to that. Are the tubes rusted on the outside? Holes in them? You could sand, prime, paint and if you wanted use a little POR15...but that is extreme and assuming that they are not rusted through. Good luck
Xris is offline   Reply With Quote
Old 12-01-2005, 12:36 PM   #5
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
Hey Xris 86 buddy thanks for the info, the bottom tube is working but it's condition is marginal and we all know that it's only a matter of time before something goes. I like to do preventative maintenance so the system is happier. I did a drill & tap with my cooling temp sensor so life is much easier if I have to repair being it is a bitch next the distributor so I don't have that problem any more. TB is aluminium OK, I don't want to spend $2-300 for a new TB so I'll look thru other threads to see if there are other tube solutions. Do you think they are Ford products? I'll check and if I found a company that makes them I'll post it. For the TPS replacement, I guess it wouldn't hurt to read the Haynes book right? THANKS BRO!
JKossarides is offline   Reply With Quote
Old 12-01-2005, 06:09 PM   #6
Sixlitre
Practicing Infidel
 
Sixlitre's Avatar
 
Join Date: Dec 2003
Location: Ottawa Ontario Canada
Posts: 15,258
iTrader: (1)
Bronco Info: 86 Eddie Bauer; EFI 5.0 liter, AOD, optimized ignition system, external tranny filter, urethane bush
Excellent write up (and pics) Xris

I'm sure a lot of us 86ers are facing similar troubles.

Question for you; When you say

" Rotate the throttle to the full-open position and the sensor should increase voltage to 4.0-5.0 volts. The maximum voltage I got was 1.85 volts. So I was for sure this must be the problem"

Surely you don't mean with the engine on ?

Thanks again

Sixlitre

I'm having a starting and running issue lately. It's kinda crept up on me because I'm driving the old gal so little.

I have to use quick start to get her going. She just rolls over like she's getting no gas, until I shoot a little alcohol down her throats.

After she's warmed up she's sluggish at all stages of part throttle, like there's not enough gas getting to it, but goes gangbusters at wide open throttle.

To complicate things I busted that rod on top of the throttle body while fiddling around under that stupid plastic cover hat. Wouldn't you know it, the Ford replacement is plastic !!!!!!!!!

I'll be looking to score a real metal/plastic one, like in your pics asap at a junkyard.
__________________
My Superford site
http://www.superford.org/registry/vehicles/detail.php?id=4970&s=17328#content
Sixlitre is offline   Reply With Quote
Old 12-02-2005, 02:04 AM   #7
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
I hate when stuff like that happens when you're trying to be careful so as not to spend extra money when fixing a problem. Today I sprayed STP TB cleaner while she was running just to make sure it's a little cleaner and it seems to run a bit better. I think the cooling tubes on the TB may screw out, but I'm researching to make sure. I think I understand the TPS better, the throttle plates need to be closed before you install a new TPS so it will open to the right angle. I have learned so much about my Bronco thru this site and I found it by accident. A plethera of information and all the money you can save by doing most of it yourself. I'm still laboring with my 02 sensor, what a bitch to get out. My buddy recommended Aero Croil deep penetrating to soak into the threads, who knows how long this one has been in there. What about Sea Foam deep penetrtating? I figure anything to make it run better, gas prices are coming down, only $2.33 per gal today OUCH.
JKossarides is offline   Reply With Quote
Old 12-02-2005, 07:54 AM   #8
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
Quote:
Originally Posted by Sixlitre
Excellent write up (and pics) Xris

I'm sure a lot of us 86ers are facing similar troubles.

Question for you; When you say

" Rotate the throttle to the full-open position and the sensor should increase voltage to 4.0-5.0 volts. The maximum voltage I got was 1.85 volts. So I was for sure this must be the problem"

Surely you don't mean with the engine on ?

Thanks again

Sixlitre
Correct...In thought I had mentioned that but I'll have to look over the thread and do a possible edit.

Sluggish at mid-throttle...do you ever get bucking/hesitation at crusing speeds? Could be the TPS. I would do the electrical test or run the codes to find out. Six...its nice to see your still around!
Xris is offline   Reply With Quote
Old 12-02-2005, 08:18 AM   #9
BikerPepe`
(this space for rent)
 
BikerPepe`'s Avatar
 
Join Date: Feb 2003
Location: N.E. WA
Posts: 23,620
iTrader: (1)
Bronco Info: '90 Custom, 302 (275hp/340ftlbs.), AOD, 4.56's, 31's, TTB Aussie Locker
Little contribution to this great thread... if your testing it before pulling it:




Hope that helps with any other testing questions.
__________________
BikerPepe` is offline   Reply With Quote
Old 12-02-2005, 08:27 AM   #10
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
Great close ups Pepe! Question though...how do you get a proper voltage check if the TPS is not connected to an electrical source? The plug is unplugged from the rest of the path...haynes suggests backprobing so there is that electronic stimulus. Let me know...Thanks Pepe!
Xris is offline   Reply With Quote
Old 12-02-2005, 04:41 PM   #11
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
OK I called Power Ford and they told me the cooling tubes in the TB are pressed in. So if anyone has actual experience in changing this tubes out please post. The only solution I can think of is to tap, thread and add new plumbing which would maker future repairs a snap as you wouldn't have to take off the TB the next time around and it's a whole lot cheaper then dropping $3-400 bucks for a new TB vs $1.00 for plumbing parts and engineering.

I keep forgetting to ask this question, what mm size is the stock TB for the 1986?
JKossarides is offline   Reply With Quote
Old 12-02-2005, 05:02 PM   #12
BikerPepe`
(this space for rent)
 
BikerPepe`'s Avatar
 
Join Date: Feb 2003
Location: N.E. WA
Posts: 23,620
iTrader: (1)
Bronco Info: '90 Custom, 302 (275hp/340ftlbs.), AOD, 4.56's, 31's, TTB Aussie Locker
The test is not an accurate one by any means.
I was only testing current to verify the unit could still move the juice.
__________________
BikerPepe` is offline   Reply With Quote
Old 12-02-2005, 09:46 PM   #13
Sixlitre
Practicing Infidel
 
Sixlitre's Avatar
 
Join Date: Dec 2003
Location: Ottawa Ontario Canada
Posts: 15,258
iTrader: (1)
Bronco Info: 86 Eddie Bauer; EFI 5.0 liter, AOD, optimized ignition system, external tranny filter, urethane bush
Quote:
Originally Posted by JKossarides
OK I called Power Ford and they told me the cooling tubes in the TB are pressed in. So if anyone has actual experience in changing this tubes out please post. The only solution I can think of is to tap, thread and add new plumbing which would maker future repairs a snap as you wouldn't have to take off the TB the next time around and it's a whole lot cheaper then dropping $3-400 bucks for a new TB vs $1.00 for plumbing parts and engineering.

I keep forgetting to ask this question, what mm size is the stock TB for the 1986?
Get to a junkyard

find a seized throttle body(they all seize when they sit) and offer the yard guy $25

Go home, clean and unseize it and away you go !

Sixlitre
__________________
My Superford site
http://www.superford.org/registry/vehicles/detail.php?id=4970&s=17328#content
Sixlitre is offline   Reply With Quote
Old 12-03-2005, 01:48 PM   #14
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
Thanks Sixlitre, certainly that's an option I will consider but then the only problem is, can I find one where the cooling tubes are in better shape otherwise I'm right back where I started with the rust etc. I will check around the salvage yards out here and see what's available, this stuff doesn't last long out here, you know everything gets picked clean. Tapping threads in isn't the most difficult thing to do either so it's just a matter of time well spent for me. Thanks!
JKossarides is offline   Reply With Quote
Old 12-05-2005, 07:42 PM   #15
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
While we're talking about cleaning and testing TB's etc. I came across this product today at Kragen. Berryman-B12 Chemtool for gas, injection, carb, oil $4.29 a can. Has anyone heard of or used this stuff, kinda looks and sounds like Sea Foam, $5.99 a can? PLease post. Thanks!
JKossarides is offline   Reply With Quote
Old 12-05-2005, 07:53 PM   #16
Sixlitre
Practicing Infidel
 
Sixlitre's Avatar
 
Join Date: Dec 2003
Location: Ottawa Ontario Canada
Posts: 15,258
iTrader: (1)
Bronco Info: 86 Eddie Bauer; EFI 5.0 liter, AOD, optimized ignition system, external tranny filter, urethane bush
Quote:
Originally Posted by JKossarides
While we're talking about cleaning and testing TB's etc. I came across this product today at Kragen. Berryman-B12 Chemtool for gas, injection, carb, oil $4.29 a can. Has anyone heard of or used this stuff, kinda looks and sounds like Sea Foam, $5.99 a can? PLease post. Thanks!
Blow the 4.29 and let us know what y'all thank

Sixlitre
__________________
My Superford site
http://www.superford.org/registry/vehicles/detail.php?id=4970&s=17328#content
Sixlitre is offline   Reply With Quote
Old 12-05-2005, 10:22 PM   #17
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
www.berrymanproducts.com, this website has many automotive products just like Sea Foam or any other auto products that have been discussed on many of the threads. Anyone can check it out and see if there are products worth trying. Good luck!
JKossarides is offline   Reply With Quote
Old 12-06-2005, 08:01 AM   #18
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
I've used it...I think it is similar to Sea Foam...I used the product to do some scrubbing.
Xris is offline   Reply With Quote
Old 03-21-2006, 08:02 AM   #19
Xris
Registered User
 
Xris's Avatar
 
Join Date: Jan 2004
Location: Rochester, MN
Posts: 874
iTrader: (0)
Bronco Info: 1986 Ford Bronco XLT
Tank - Check out Fordfuelinjection.com for the appropriate readings. I think they are on there. If I remember correct it should be around .90-1.00. Check the site.

Did a little checking .50-1.0 volts. You may have to adjust your tps position slightly. Check your haynes.
Xris is offline   Reply With Quote
Old 09-04-2007, 05:34 PM   #20
JKossarides
Fullsize Member
 
JKossarides's Avatar
 
Join Date: Apr 2005
Location: Rolling Hills Estates, CA
Posts: 9,128
iTrader: (1)
Bronco Info: 1986 Bronco XLT 4x4 -AOD -Warn Hubs, NEW stock 302EFI (2008) All MSD ignition, 9mm FMSR wires
I'm trying to dail everything in before Smogorama at the end of this week.
I have a spare TB on the bench with the TPS still on and I'm trying to learn how to probe for voltage on the blade angle.

I have a Craftsman digital multimeter #82082 but I'm not sure which setting to use to see .95v closed to 4.5-5.0v WOT.
So which setting do I use, V-DC, V-AC, A-DC or OHM? I'm thinking V-DC with the Haynes by my side ~

This is my least favorite part, it's all greek or I'm dyslexic ~

Thanks ~
JKossarides is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  FSB Forums > Bronco Discussions > Technical Write Ups


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 01:32 PM.


2003-2009 FullSizeBronco.com. All rights reserved