'92 Bronco full size...sluggish take off

[vzfox]

'92 Bronco 4x4, 351 Windsor, auto.....

Barely press the gas pedal and all is good, but press it more than 1/4 way down and it gets sluggish and acts like it dont want to go. Floor it and it takes off. Its only the 1/4 to 3/4 pressing of the gas pedal that it acts sluggish. All gauges read really good on everything and the idle is good, dont hear a miss or backfire. No check engine light or anything comes on at any time.

What should i look at?

[rhandwor]

I would look at the throttle position sensor use an ohm meter and see if the resistance changes. If you have a scanner check the voltage and see if it changes.

[vzfox]

i checked the voltage and ohms today....voltage reads .98 to 4.60

Not sure if you or anyone has replaced a TPS on a 5.8L Windsor before, but it appears the TPS is located on the bottom of the air intake valves and is impossible to get to. Any hints on how I might go about getting it off and replaceing it?

[rhandwor]

I've done them on a 5.8 pickup. I had to unbolt the air intake hose you are talking about. I think I also bought a new gasket or made one. You can cut one out of a sheet of gasket material. Check the price while at the parts store. A flange with nuts attached to 4 studs if I remember correctly.
Easier than you think.

[vzfox]

I replaced the TPS, EGR solinoid, dist cap and rotor.....none of which made a bit of difference. It is still sluggish when the gas pedal is pressed between 1/4 and 1/2 way down.

Now what tests should i perform and what parts should i look at?

[rhandwor]

Pull the vacuum line for the fuel pressure regulator and check for fuel if it is leaking replace it. If you have a gage check the pressure.
Use a timing light and check if the computer is moving the timing.

[vzfox]

Originally Posted by rhandwor

Pull the vacuum line for the fuel pressure regulator and check for fuel if it is leaking replace it. If you have a gage check the pressure.
Use a timing light and check if the computer is moving the timing.

How should I check the timing? I mean, what (if any) vacuum lines need to be removed/plugged to check the timing? What should the timing be set at when at idle?

[rhandwor]

Set timing 10 degrees BTDC with the yellow/light green wire near distributor disconnected. If a two wire remove shorting bar near the firewall by the drivers side fender.
Normally they have a tag on them.
After the timing is set connect the wire after shutdown.
Then restart the engine and make sure the timing advances when the engine speed is increased this usually is over 30 degrees.

[vzfox]

Originally Posted by rhandwor

Set timing 10 degrees BTDC with the yellow/light green wire near distributor disconnected. If a two wire remove shorting bar near the firewall by the drivers side fender.
Normally they have a tag on them.
After the timing is set connect the wire after shutdown.
Then restart the engine and make sure the timing advances when the engine speed is increased this usually is over 30 degrees.

I was unable to find any single wire, no matter the color anywhere near the distributor. Believe me, I searched all over for 20 minutes. The distributor has about 10 wires that plug into it, all plug into a single molex connector (unable to unplug just one wire). All other wires near the distributor go to something, like TPS and water temp sensors and fuel injectors. I also searched the drivers side firewall/fender for this other wire....again, no such wire.

I did check the timing without unplugging anything (obviously) and found it at 10* BTC at idle warm. When the rpm's are advanced up to 2500rpm, the timing moves to 25* BTC. Does this sound correct?

Again, it idles really good and as long as you press the gas pedal 1/8 down it will pick up speed normally. but when pressed more than 1/4 and less than 3/4 the way down, it acts like it dont want to go. floor it and it will haul ass.

[rhandwor]

The one with the shorting bar is two wires. Look again close to the firewall and drivers side fender. I usually worked on 5 liter motors but the timing always moved around a lot and moved more than what you are showing.
My son had a 5.8L Ford pickup but I didn't check the timing on it as he didn't have a problem.
Ask way to old the Crown Vic moderator as he does a lot of police car work.
I don't think your timing is correct.

[vzfox]

Well, I dont know what to tell ya.....I just spent another 35 minutes under the hood of that truck and never once found anything resembling what your talking about. I have no idea what a "shorting bar" is or what it looks like. The only thing at the drivers firewall fender is my EEC test connector and ABS test connector. On the fender itself is the power distribution box, and all the fuses in it are good.

The only thing I can think of next would be to see a picture or pictures of this wire(s), an exact color and an "exact" location. If your still willing to help, please let me know where I can find pics and details.

[vzfox]

Let me just start by saying.....I FOUND THE TIMING SPOUT CONNECTOR!!

http://www.fordfuelinjection.com/images/selftest02.gif

using the image above that someone posted along the line, I was able to go right to it. I found that the timing was off by about 9*....I adjusted it and plugged the spout connector back in. It still idles just as smooth as it did before.

I will probably get it out on the road sometime this weekend and get back to you to see if that was the fix or not for my sluggish issues.

[vzfox]

Originally Posted by vzfox

Let me just start by saying.....I FOUND THE TIMING SPOUT CONNECTOR!!

http://www.fordfuelinjection.com/images/selftest02.gif

using the image above that someone posted along the line, I was able to go right to it. I found that the timing was off by about 9*....I adjusted it and plugged the spout connector back in. It still idles just as smooth as it did before.

I will probably get it out on the road sometime this weekend and get back to you to see if that was the fix or not for my sluggish issues.

By re-adjusting the timing to the correct setting, my issue has now been resolved . thank you very much for your help and support.