1995 Bronco. 5.8L, 143,000 miles.

* Check Engine Light just came on this evening. (has never come on before)
* Trans now shifts Hard, particularly into reverse (big clunk)
* Drive shifting seems very different/off...
* Idle in park is higher now at ~1200+ rpm.
* Seems to have burned thru a 1/4 tank in very few miles (may be subjective)

I went to local Auto Shop, but is closed on Memorial Day. I will get them to pull codes tomorrow, if I can.

Any Hints, experience w/ this? Am sure some of you smart guys have heard of these symptoms and can advise me.

Is vehicle OK to drive to work tomorrow? (50 miles RT)

Can I pull codes myself?

Thanks in advance for your responses.

 

I followed the information from Ford Fuel Injection How To Run a Self-Test, and get the following:

122, 122 -- pause -- 122, 122

I"m guessing this is KOEO of 122 and CM of 122.

From the link it states:

KOEO: "TPS circuit below minimum 0.6 volts."
CM: "TPS circuit has intermittently failed below minimum 0.6 volts."

So, Throttle Position Sensor bad?? Is this simply replaceable item? Does it explain the symptoms?

 

You may be in limp mode. The TPS is on the bottom of the throttle body. You can test it with an analog meter, not digital, for bad spots as the throttle is opened. Remove the TB to get to the TPS. If you have time before the trip tomorrow you may want to try just cleaning the connector near it. Then disconnect negative cable for as long as you have time 20-30 minutes to clear the codes. If not better then get a TPS on your trip tomorrow. It is a wear item, so probably time for it.

 

Check your fuses, my brothers did this after he took the top off because accidentally cut the wire for the 3rd brake light. The 3rd brake light shares a fuse with the PSOM which picks up the signal from the VSS and tells the computer when to shift and how fast you are going. It would shift really hard and took for ever to shift from 1st to 2nd and every other gear once you were moving because it lacked the proper inputs. Just something easy you could check I never would have guessed a brake light fuse could have made you think the tranny was shot but it sure did.
-Johnboy

 

I did as b4hntn said last nite -- I found the connector that the TPS pigtail connects to and disconnected, blew it a bit w/ shop air, and reconnected. I [also] tapped the sensor housing [on base of Throttle Body] a few times w/ a screwdriver. I disconnected battery for about 30 mins, also. Upon retry, Check Engine lamp still came ON after key-on/engine start, and the big 'clunk' when going into reverse. Fiddlesticks!!

So, I let my GF drive it to her work today, and she texted me a while ago saying the C.E. lite never came on this morning, nor along the entire way to work. WTF? Gremlin dead?

I'm guessing this issue will re-appear, so I'd still like to hear any suggestions ya'll might have.

Thanks!!

 

replace the tps and make sure its adjusted properly according to the fordfuelinjection website.

 

I ended up replacing the Throttle Position Sensor tonite. It seems to have done the trick.

My GF said truck was fine on way to work this morning, but later acted up again at lunch and on whole way home. Heavy clunks into reverse, and bad shifting on the way.

I picked up the Sensor at Pep Boys for $33, bought a six pack of beer and went to town. Got the throttle body off pretty easily, and noted that it was clean on the outside (air intake side) and filthy on the other side of the butterflies. Did the ole toothbrush and carb cleaner trick -- went well. Time came to take the Sensor off and could NOT turn those two phillips head screws. Could sense them ready to strip -- you know the feeling! I dowsed in Penetrating Fluid and had another beer and checked this website to kill time. Tackled again bout 20 minutes later w/ the 'next size up' phillips head after a couple taps on the head w/ a hammer, and carefully turned them -- they both broke free. Whew. Was passing bricks before this.

Was confusing to install the new sensor tho. Thought it would 'slip on' just fine, but did have to install 'off' a bit, then turn the unit til screw holes lined up. This was a tad concerning as I didn't expect the TB 'tab' to have to apply a bit of a 'pre-load' on the sensor (I hadn't read about this in the many posts I read prior). Also VERY alarming was that the aftermarket sensor has the wire colors different from the OEM in respect to orientation. The sensor has an orange, green and black wire. The orange and green were reversed on the aftermarket part. I decided to keep the installed orientation the same as how I removed the original, and it appears to be just fine.

Test drove around the block, and no Check Engine lite, no clunks into reverse, and shifting is all good again. Floored it a few times, all seems groovy.

Not a hard job at all really -- a couple hours and 4 beers total. Anybody could really do this, but my learning points are these:

1. HAVE Penetrating Oil handy, and use it!!!!!
2. Use the 'next size up' Phillips head screwdriver than usual when removing the screws from the TPS -- they look like the typical (no.2?) ones, but deceiving. You do NOT want these puppies to strip out.
3. Aftermarket units may have wiring colors different from OEM. I installed in same way the orig came off (wires in same direction as orig) -- the body/shape of aftermarket is roughly the same.
4. Sensor didn't just 'pop into place' like expected. I had to turn back a ways to get it to seat, then twist -- applying a bit of a preload on the mechanism, then lined up the screws and secured.

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Please correct anything I may have wrong here, as this was my first time w/ this.

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For reference, in the future, if anybody has the check engine lamp come ON, pulls codes and gets a 122, 122 (MY95 5.8L), and shifting gets funky, consider the Throttle Position Sensor to be replaced. It seems to to have worked to me.

Cheers!

 

Success is great for the ego. One of the screw heads broke off on mine but left enough screw to remove it after TPS was off.