FIPL/TPS and Transmission problems

[TurboMatt]

I recently picked up a 1994 7.3 IDI non-turbo (my first diesel) truck. I'm having some issues with very hard up-shifts. I followed the guide (via search) on here to adjust the FIPL/TPS. I immediately ran into issues as I was unable to get up to .9-1.2 v in the idle position. With the bracket loose and swung all the way I can get .66v in the idle position at 3.05v at WOT position. I have 4.99v on the power wire and the ground is good. So, I replaced the switch with one from Advance Auto and have the same exact measurements.

NOTE: The previous owner stated that the injection pump was very recently rebuilt so I'm not sure if maybe the cam that drives FIPL is not positioned correctly, assuming it's adjustable.

Ideas?

Thanks!
Matt

 

['94IDITurbo7.3]

If i am understaning you correctly you are expecting the idle voltage to be with in spec if you have the TPS swung all the way towards one direction. That is not the case.

I forget which way increases the voltage but when you have the idle voltage w/ in spec the TPS will not be "bottomed out".

You will have to have your digital volt meter pluged into the TPS and the ignition on with engine OFF, then loosen up the two torx screws that secure the TPS. Then rotate the TPS until you get an idle voltage w/ in the range of .9-1.2V. The higher the idle voltage, the firmer and later the shifts.

Also look for the voltage to increase smoothly as you opperate the throttle.

Good Luck

 

[icanfixall]

The above posting is correct. .96 to 1.2 at the idle setting tested by the center green wire and a digital voltmeter. Place the ground on the battery. I always test my voltmeter before I use it on the positive and negative leads on the battery. Both to the posts and to the clamps. I'm looking for any resistance. Then I test the TPS. Small movements of the switch will show an increase or decrease in tested voltage.

 

[TurboMatt]

I appologize but I should have been more clear. The MOST voltage I can get at the idle position is .66v. That's with the top of the TPS being swung towards the radiator, or counter-clockwise if looking at TPS from the drivers side fender. If I swing it back the other way voltage goes down. With the TPS removed from the bracket I see .45v. One thing that is interesting is the only time I see a voltage change is in the last 1/16" inch of bracket adjustment. Seems like there is something physically wrong with the cam that operates the TPS or the sensors themselves are wrong (bought from Advance Auto).

One of the bigger things I see is a problem is I'm only seeing a total of 2.3v change through the whole sweep of the TPS. Based off of all the FAQ's I'm seeing, total voltage change should be around 3.0-3.5v. That's quite a difference for a 5v signal circuit.

Thanks
Matt

 

['94IDITurbo7.3]

I appologize but I should have been more clear. The MOST voltage I can get at the idle position is .66v. That's with the top of the TPS being swung towards the radiator, or counter-clockwise if looking at TPS from the drivers side fender. If I swing it back the other way voltage goes down. With the TPS removed from the bracket I see .45v. One thing that is interesting is the only time I see a voltage change is in the last 1/16" inch of bracket adjustment. Seems like there is something physically wrong with the cam that operates the TPS or the sensors themselves are wrong (bought from Advance Auto).

One of the bigger things I see is a problem is I'm only seeing a total of 2.3v change through the whole sweep of the TPS. Based off of all the FAQ's I'm seeing, total voltage change should be around 3.0-3.5v. That's quite a difference for a 5v signal circuit.

Thanks
Matt

I would agree with something going on with the cam.

 

[TurboMatt]

I would agree with something going on with the cam.

I would suspect that since the injection pump was recently rebuilt. Does anyone know how to adjust the cam on the side of the pump?

 

['94IDITurbo7.3]

I would suspect that since the injection pump was recently rebuilt. Does anyone know how to adjust the cam on the side of the pump?

There are two set screws that holds the flapper thing on that moves the TPS. There is a correct way and a wrong way to put that on. My guese would be that it is on wrong. I would take it off and put it on in the other position. If you don't know what i am talking about while reading this you will understand once you take the TPS off and take a look at it.

 

[icanfixall]

I too agree with the above posting. When that throttle thing is properly installed on the shaft you need to wind the tps on to it to reach the screw holes that holds the tps setting. I feel if you do this your issues will be solved. Its kinda like this. You have two choices to set the actuater on the throttle shaft. You may just have it on the wrong setting and removing it will tell you whats going on. Take a look at the old tps. See where the actuater was touching the inside of it. Once you figure this out you will know what I trying to explain. If I could show you in a viedo I would but I don't have the bracket the tps connects to. I have a spare tps. A spare couple of the actuaters and a spare pump or two.... Haven't been able to find the bracket yet...

 

[TurboMatt]

This photo shows how far I had to rotate the bracket to get the .66v setting.

You must be registered for see images attach

I labeled a few parts to better help with what I'm talking about. What I assume I need to move is the part labeled as #2. With the TPS off, the cam at the end sits level, at least to the naked eye. Not sure if this is right or wrong.

You must be registered for see images attach

Now something else I found today which I hope this is easy to understand. I removed the TPS bracket and held the TPS on the shaft so it would be at .90v in the idle position. I moved the throttle cable to the WOT position I was able to achieve 3.2v, still very far from the 4.0-4.5v I've read is normal. I returned the throttle to idle position and found .90v, back to WOT again found 3.2v. So now it seems as if the shaft doesn't even move far enough.

I'm going to see if the local Ford dealer has an OEM TPS sensor to play with as well. Something is off, that's for sure!

 

[icanfixall]

Do not play with the number one in your pictures. That will do nothing but mess up your pump. Like I posed before. Look at the tps you replaced and see where the number two pictured item contacted it. They need to wind up some as your installing them on the bracket. .96 to 1.2 volts ignition on engine off. The wide open setting is not adjustable when you have the low setting you desire. That means if you set the tps at .96 the high voltage will be what it is. You just live with that. Now if you set the tps to 1.2 you will find the high voltagw or wide open voltage higher than before. Its because you started with a higher voltage being 1.2 is higher than .96... You don't need to worry about the w.o. v. Sorry for so much confusion in how I'm posting this... You will understand...
P.S... I would change out the two adjusting screws to a 1/4 28 bolt. They are much easier to get a wrench on. Use a washer to spread out the clamping too.

 

[TurboMatt]

In the position it's in now I was able to get a little wind up but not much. I tried to move the TPS bracket all the way through the sweep while mounting and un-mounting the TPS and the way it sits is the only way I can get anything about .45v.I will try to re-mount the TPS again but it appears that the cam coming out of the pump is position wrong.

Does anyone have any pictures of an injection pump with the TPS off?

 

[TurboMatt]

I've done some more research and spoke with the previous owner some more. Turns out the injection pump was actually replaced, not-rebuilt locally. The cam that drives the pump looks like it's actually in the wrong position. So, at this point it looks like the easiest option would be to drill two new holes in the TPS bracket to allow the TPS to be positioned correctly. Short of pulling the injection pump off the truck, I can't think of an easier option.

Thoughts?

 

['94IDITurbo7.3]

You had described that the flat on the #2 part in your picture is level. I am pretty sure that it should be on an angle.
With the TPS off and looking at the #2 part (from your pic) from the driver's side, the right side of the #2 part should be higher than the left side.

Sorry if this is coonfusing. This is definatley one of those times when a picture is really worth a thousand words.

I had taken some pics from when i did my IP but all my pis have the TPS on.

 

['94IDITurbo7.3]

I notice that your TPS has a black casing on it. Don't hold me to this but i think i have heard on here that you should get the one with the grey casing on it b/c it is updated.

 

[TurboMatt]

You had described that the flat on the #2 part in your picture is level. I am pretty sure that it should be on an angle.
With the TPS off and looking at the #2 part (from your pic) from the driver's side, the right side of the #2 part should be higher than the left side.

Sorry if this is coonfusing. This is definatley one of those times when a picture is really worth a thousand words.

I had taken some pics from when i did my IP but all my pis have the TPS on.

That actually makes perfect sense. Thank you for the clear explanation. The injection pump is a reman but the previous owner wasn't sure if it was a NAPA, Ford, etc....just that it was reman. I still haven't got the truck inspected and tagged so once I do that, I'll drive it down to the shop that did the injection pump and see what they say.

Regarding the TPS. I picked a new one up from Advance Auto and it looked exactly the same. So, I returned it and bought a brand new one from the local Ford dealer. Believe it or not, it was black as well. I've seen the mention of the grey TPS' however all three read exactly the same in regard to voltage vs physical sweep of the sensor. My issue seems to be a physical mounting issue with the ip.