New TPS

[Ole BlackBetty]

Today I installed a new TPS in my truck, set the idle by tach at about 650-700 rpm ( less than half way between 500 and 1000, on truck tach gauge). settings are 1.25 volts at idle and 4.03 volts at WOT. Driving to work tonight I noticed truck seems to shift late, but solid. 1st to 2nd shifts at about 24mph or 2500 rpm, 2nd to 3rd shifts at about 38mph or 2500 rpm, OD kicks in at about 55 mph. I believe I need to set volts at idle, a little lower so it will shift sooner, as shift is a little hard from 1st to 2nd, what would be a low, safe setting at idle, or is it more trial and error, until it feels right? Truck has 4.10 gears

 

[FORDF250HDXLT]

your just off slightly on the axis.tone it back down to 1.2V idle,while getting closer to 4.5V WOT.time consuming but worth the effort.

 

[Hydro-idi]

It is kind of up to you. The proper way is to set it with all that electronic stuff but I have adjusted mine to how I like my transmission to shift.....I might get bashed for that lol. I just played with it for a while until it felt right to me.

 

[Ole BlackBetty]

Is there a way to adjust the spread of the idle and wOT settings? If I bring the idle setting closer to 1.2 volts, that is going to lower the WOT setting to about 3.98 volts.

 

['94IDITurbo7.3]

it's a royal pita to adjust. i just got lucky getting mine close.

 

[GenLightening]

The high setting is not what you're aiming for, you just don't want it to go over 4.5v. Adjust the lower end to between .93v and 1.25v depending on how you want it to shift (lower=softer, higher=firmer). There is no way to adjust the spread.

 

[Ole BlackBetty]

Thank you all for your comments.

Is there a way to connect a tach meter to these trucks, other than trusting the dash gauge, or does it take special equipment? I have a tach / dwell meter I use on my gasser, but it connects to the coil wire, which we dont have.

 

[riotwarrior]

First, my single handed knowledge of these transmissions is a little less than none! Second I enjoy reading about these issues and learning about them as I plan on an E4OD for the Bronco now...I know change of plans...so Wifey can drive it, and we can make it our car....so to speak that we both can drive!

Now just a point of interest here and it's an observation of mine from many years of older non comp controlled autos, a firmer shift is better for the transmission in the long run, it keeps the engagement of clutch packs shorter and lessens heat build up. Now this is for transmissions I'm familiar with C6 T350/400 727 etc, all will benefit from a quicker shift saving material and lessening heat buildup. This is even more important when you are loaded down.

If the above holds true for these electro trans....then IMHO you would want the firmer shifting trans over the comfort shift. JM2CW but I want longevity over comfort.

Can anyone confirm that my theory is either incorrect or correct on shifting these electowonderwizardtransmission?

Al

 

[icanfixall]

The tps setting are factory .96 to 1.2 volts at idle key on but engine off. The lower setting makes for a smoother shift and higher setting a firmer shift. We have no way to change the spread of volts from wide open back to idle. At 5 volts wide open throttle position the cumputer shuts down and you end up in limp home mode... Not a good place to be because its shifting vey harsh and is designed to get you home a short distance or just off the road to safety. What you end up with is second gear and reverse only. Back down your idle setting to 1.2 volts and try that. Its well posted here whats going on with the setting you choose. The members that tell me they just hunt around for what feels good scares me some but its what they feel works for them. Who am I to say it doesn't work. Its true, there is a special tool and meter to set these tps but many of us have found a good quality digital voltmeter works great. To make sure these setting are done correct the engine needs to be warmed up or the internal advance and the fast idle will ruin the settings. I like working on a cold engine so I remove the wire to the pump advance and the fast idle solenoid. Then I can touch the engine without getting burned...

 

[FORDF250HDXLT]

So yeah, personally I'd rather just go take a nap than fiddle w/ TPS for hours on end.

go take a nap old timer,leave the fine tuning to us young guns.

 

[icanfixall]

I like naps too... But I nap better when I know what I have done mechanically to anyhing I'm working on... It works for me that way just like another hunting for a sweet spot... Hel, even a blind squrriel finda a nut once in a while too.

 

[trackspeeder]

I use the factory spec as a base line. No fancy tool just a meter.

Once I have a base line, a test drive is required. After that I will give the TPS a twist to fine tune it.

So there is really nothing wrong with hunting around for the desired shift schedule. Just don't go to crazy with it.

 

[IHcornbinder]

Ok so a little off topic for this thread but please redirect me if you know what thread im looking for. I have fiddled with the vacum modulator "TPS" thingy for my 85' c6, and the kickdown linkage and have got it somewhat close. I still get a VERY voilent shift sometimes if i get just the right (or wrong) throttle possition. I would really like to find a step by step calibration of this ancient technology, or atleast some advise from an old timer. Any info would be greatly appriciated. Thanks

 

[Ole BlackBetty]

I use the factory spec as a base line. No fancy tool just a meter.

What is the factory spec, in voltage?

 

[Ole BlackBetty]

I got the tps adjusted to 1.14 Volts . It seems to shift real nice, not slipping into gear, solid shift, but not neck breaking. Now if the od light just dont start flashing again, i will be a happy camper!