Tach, and Shifting

[justinray]

Hey guys, I'm a new member, joined mostly to ask this question about my truck, but first of all, i have a 1993 F-250 4X4 7.3 IDI NA E4OD Bone Stock, my problem is that my tach does not work until i get to around 1600 rpm, and when between gears, for example, cruising 55 between 3rd and 4th, it shifts repeatedly up and down between 3rd and 4th, the only way i can stop this is if i turn overdrive off, or speed up to 60. Are the two problems caused by one culprit? the tach sensor? Someone please help.

 

[hesutton]

I'm not an E4OD owner, but I know that without a properly functioning tachometer, the transmission will not function properly either. It needs that signal to work as it should. You may need to get a new tach sender. Ford part number is E5TZ-17B384-A. There may be other issuses at play here, but that needs to be fixed without doubt.

And, WELCOME TO OB!

Heath

 

[mattplumber]

Welcome. Sounds like tach sender to me. Classic case. Do you know where the sender is located? Its on the upper injection pump gear cover. Check to see if the 2 wires coming out of it are frayed at all or have oil on them, if so, it the likely culprit. Ive always had zf-5 trucks so the tach working or not has never affected me. I have driven an e4od truck though with a bad tach sender and suddenly realized how important it was to the auto tranny.

 

[DragRag]

What Matt said, replace the tach sensor, problem solved.

 

[justinray]

Just walked outside, i assume its the 1" Nut next to my Oil fill cap?, one wire is fine, the other is stripped for the first inch out of the Nut, it looks like i cant remove this without removing my vaccuum pump, is this true? maybe just remove it and clean the wires and tape them up?

 

[Blind Driver2]

That's it. It comes out easily. I'd replace it without removing the pump.

Someone might chime in letting him know how far to screw it in. I forgot

 

[justinray]

Thanks, I'm gonna go do that, i'll come back in when i finish and let yall know how it goes.

 

[justinray]

No change, however i also noticed something, the wire clusters together with the AC Compressor Clutch Wire, Which also does not function, maye there's a chance that the wire cluster is messed up as a whole, however the Volt meter does work, which is also on that same wire bunch.. Hmmm..

 

[mattplumber]

Awesome bud, good luck. 10 min job, and you dont have to remove the vaccuum pump FYI.

 

[justinray]

Dummy tested ac clutch, the clutch itself is out, so i'm pretty sure the Tach sensor is a standalone problem, i'll buy one come next paycheck, til then i presume that its okay to run as-is?

 

[OLDBULL8]

The tach sensor wires have a connector, make sure the contacts on the connector are clean. Sounds like you have Hi resistance on the connector, if you are getting a signal at hi RPM's.

 

[Compu Doc]

I cut and pasted this from a thread that I responded to yesterday and the following was my response in that thread:

I found the following by searching the P/N with Google.

Quote:
I bought a new RPM sensor today at the Ford dealership...$80.
Ford only part: Engine RPM sensor E5TZ-17B384-A

Here's how to check yours:
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC/ 0 to 40-volt scale..
4. Start engine in park. Raise rpm while watching DVOM.
5. Voltage must increase or RPM sensor is bad.
That took care of the error 14 I was experiencing.
Quoted from http://www.powerstroke.org/forum/7-3...-7-3l-idi.html

The funny thing is this is in a powerstroke forum but the truck this guy owns is an IDI, I wonder if her knows about this site.

 

['94IDITurbo7.3]

I am not sure but i think i have heard that a bad TPS will cause the tranny to shift like you descibe, hunting for a gear at a certain speed and then once you increase speed it will stop hunting.

Good luck and welcome!

 

[icanfixall]

Welocme to the forum..These E4OD trans needs the tach to tell the trans how to operate. Please don't continue to drive the truck like this. You will surely ruin the trans. Now about the injector pump TPS found on the drivers side. It has to function by sending voltage to the computer located behind the drivers side footwell cover. The center wire is the pickup you need to test from. turn the ignition key to the on position engine not running. Now test the voltage at the idle setting. It must be at least .96 volts... sounds like not much but its important. Now advance the throttl wide open. The voltage will go up. Probably up to around 4 volts. If the computer sees 5 volts it will dump the system and you end up in the famous "limp home mode"... Thats just second and reverse. It enough to get you out of danger or off the roda to safety. This voltage usually is set between .96 and 1.2 volts. The 1.2 volts is usually a firmer shift and the .96 is a softer mushy shift..... A good quality digital voltmeter is used for this test voltage.

 

[seawalkersee]

I cut and pasted this from a thread that I responded to yesterday and the following was my response in that thread:

I found the following by searching the P/N with Google.

Quote:
I bought a new RPM sensor today at the Ford dealership...$80.
Ford only part: Engine RPM sensor E5TZ-17B384-A

Here's how to check yours:
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC/ 0 to 40-volt scale..
4. Start engine in park. Raise rpm while watching DVOM.
5. Voltage must increase or RPM sensor is bad.
That took care of the error 14 I was experiencing.
Quoted from http://www.powerstroke.org/forum/7-3...-7-3l-idi.html

The funny thing is this is in a powerstroke forum but the truck this guy owns is an IDI, I wonder if her knows about this site.

Where was this info a month ago when I was looking for it.

Does anyone here have a way to add this to the IDI list of FAQs or problems.

Good post.

SWS