Throttle Position Sensor 91 F150 5.8l - Off-Road Forums & Discussion Groups
Ford 67-96 F-Series, 78-96 Bronco All discussions of 67-96 F-Series Trucks and 78-96 Broncos

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 03-21-2005, 09:51 PM Thread Starter
Gonz's Avatar
Join Date: May 2003
Location: Renton WA
Posts: 24
Thanks: 0
Thanked 0 Times in 0 Posts
Throttle Position Sensor 91 F150 5.8l

Troubleshooting a racing idle condition. Idle speed is out of control after truck warms up. Can you help me identify the sensors( or valves or whatever ) on my throttle body in the pictures ? Also, where is the TPS ? thanks.


Gonz is offline  
Sponsored Links
post #2 of (permalink) Old 03-21-2005, 10:35 PM
Posts: n/a
Re: Throttle Position Sensor 91 F150 5.8l

best bet is to get a haneys book for the truck. Also on the earlier fuel injections there is a idle air control motor. I dont know if your truck has this but it can cause the idle to go up and down or even stall when you put it in gear. This can also be caused by O2 sensors it will cause the truck to run lean or to rich and mess up the idle. If the truck does not have O2 sensors than it has a mass air sensor and this also could cause this. If it is the mass air or the Os's than it will run fine for about 1 min. until the computer tries to read the sensors and then it will idel up and down. I hope this helps.
post #3 of (permalink) Old 03-23-2005, 01:46 AM
Posts: n/a
Re: Throttle Position Sensor 91 F150 5.8l

Check for a vaccum leak. I had very same trouble with my '93 and I had a severe vaccum leak at the lower manifold. My truck would start and idle at about 1000 rpms a bit high but after raising RPMs it would idle at over 1500 RPMs way too high. It is at the shop now I am picking it up tommorrow. It is a six hour job according to book time to repair. Hope this helps.
Sponsored Links
post #4 of (permalink) Old 04-01-2005, 07:49 PM
Join Date: May 2004
Posts: 30
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Throttle Position Sensor 91 F150 5.8l

I had a bad vacuum leak at the throttle body gasket on my bronco and it screamed rpms.
FoundOnResDead is offline  
post #5 of (permalink) Old 04-01-2005, 08:35 PM
Join Date: Apr 2001
Location: eustis , Florida
Posts: 1,444
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Throttle Position Sensor 91 F150 5.8l

cant tell you what sensor #1 is since an 86 dont have that one, sensor #2 (actually your idle air by-pass motor) but if your looking for the TBS sensor, in your first pic under the the throttle body above your pink #2 you see a green and orange wire, that goes to the tbs.

Six hour job to r&amp;r a intake manifold????, i installed my complete 5.0 EFI long block in 5 hours from crate long block to running and reinstalling the hood...

Maybe it says a six pack per hour [img]/ubbthreads/images/graemlins/40BEER.gif[/img]
BRONCOMANIA is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

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
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome