1990 Bronco Performance Problems - 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 12-02-1999, 07:53 PM
Posts: n/a
1990 Bronco Performance Problems

I have a 1990 Ford Bronco with a 351. My problem is that the truck idles rough when it is warmed up. It feels like it has a lot moer power when the engine is cold then when its hot. It idles fine when its cold, but not when its hot. What should I look for?

The oil gauge also seems to not work properly. It indicator is always around the middle. It never goes down when the engine is warm and it never goes up when the gas is pressed. It does move a little sometimes, but a little.

Any help would be greatly appreciated. Thanks!

Sponsored Links
post #2 of (permalink) Old 12-04-1999, 10:26 PM
Posts: n/a
Re: 1990 Bronco Performance Problems

Well, the good news is that you can easily replicate the problem. It sure beats having an intermittant problem
I think I would start by warming it up good, then checking EEC computer codes with a code reader, both Key ON, Engine OFF, and Key ON engine ON. I think this would be a good place to start, 'cuz the computer may already see something its not happy with, and that can save time and $ of guessing. But don't take the code as the gospel, as it can only make its code decisions on what it can see.
If you aren't familiar with the code reader for this pre-OBDII vehicle, it's a plug-in little adapter with an LED on it, comes with a manual, plugs into diagnostic connector usually under the hood on drivers side near firewall. It has instructions and they are pretty simple. Parts stores sell them, as does Sears in the tool area. About $35, I think.
That's what I would do first, before replacing any parts.

post #3 of (permalink) Old 12-05-1999, 10:48 AM
Posts: n/a
Re: 1990 Bronco Performance Problems

Take a look at the CTS (coolant temp. sensor). I've work on a few vehicles that run good when cool but when they warmed up the ran like crap. If the sensor is bad it causes your computor to think the engine is cold when it is hot which in turn makes the engine run very rich (about 8:1 instead of 14.7:1).
and about 50% of the time a bad CTS won't trip a code so you might have to OHM out the sensor with a meter.

Do'n it with only 6 cylinders!
member of Team boarcock off-road club
Sponsored Links
post #4 of (permalink) Old 12-10-1999, 03:28 AM
Posts: n/a
Re: 1990 Bronco Performance Problems

Your oil pressure gauge doesn't work 'cause it's nothing more than a glorified idiot light. As long as you have 4.5 lbs of pressure it reads Normal.

'90 Bronco/351/E4OD/4.56
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