need voltage values (or more)!! Reward $50

[Rangermilitia]

hey, does anyone have or know what the proper voltage paramaters are for a tps sensor? i keep triggering a code 23. but i replaced the tps and it still comes up. looking deeper, i checked connections at ecu and tps, i even opened the loom up to see if i could trace the wire to the ecu to check for shorts.. nothing found!! i'm stumped. i'll pay 50 bucks for the person that figures this shi% out!

some more clues..
runs rough for the first minuite or two (hot or cold)

weird feeling while accelerating (like someone is pulling me back)

sometimes while driving the motor will cut out, then in, then out, then in then its ok. only once did it die and not come back on for a few minutes.(been doing this for years!)

i have replaced the 02 sensor, tps, map, even tried a different ECU.

I know one of you can help!

 

[Psychopete]

There is a 5 volt reference, signal to computer and ground.

The TPS is a variable resistor, regulates how much of the 5 volt reference gets sent back to the computer depending on how far open the throttle body is. Should be around .98 volts at idle and around 5 at wide open throttle. With some probing of the connector, it's pretty simplistic to find which is which (don't have an accurate diagram w/ me).

FWIW, TPS sweep test should be done w/ an analog volt meter. Basically, just makes sure that the voltage throughout the range stays consistent (no dead voltage spots).

Pete

 

[Rangermilitia]

thanks for the quick response

to clarify, should i check the voltage while the truck is running, or can i do it while in ignition setting? and if voltage is less than .90 should i crank the throttle untill it is?

 

[Psychopete]

to clarify, should i check the voltage while the truck is running, or can i do it while in ignition setting? and if voltage is less than .90 should i crank the throttle untill it is?

You can check it with the ignition only on 'Run'. Although checking it while running might yeild different results than not (loose / bad connection?). The code doesn't directly hint at a problem with the sensor itself..

That screw is solely for setting the base idle voltage, computer controls the idle.

From .90 - .98 should be a small tweak. If it doesn't help or make matters worse, just simply set it back.

I swapped a different throttle body and tore it apart to clean it throughly, didn't mark where that adjustment was, and that's what I set mine to (based on information from this site).

Pete

 

[Rangermilitia]

ok i'll set the voltage at idle to .90, i messed with the screw and didnt remember where it was supposed to be, thanks for the info. i'll keep posting to keep updates.

 

[Rangermilitia]

nothing so far

now i put my tps to the .90 and now my idle is way too high. pulled codes for koeo and got 11's. then did key on engine running and got codes 12, 13, 77. please help. got $50 on it. i swear a personal check will be sent. please help.

 

[Psychopete]

now i put my tps to the .90 and now my idle is way too high. pulled codes for koeo and got 11's. then did key on engine running and got codes 12, 13, 77. please help. got $50 on it. i swear a personal check will be sent. please help.

How low was it before?

Codes 12 and 13 are generally related to the IAC valve. Was the idle screw adjusted to try and band-aid a previous high idle problem? Does the idle speed change when the IAC is disconnected?

See here:
http://www.fordfuelinjection.com/?p=39

77 means you didn't hit the throttle when it output the goose pulse.

Pete

 

[holyford86]

I just set my idle to the following procedure:

get the truck up to operating temp and shut it down.
Unplug the IAC and start the truck (you may have to give it a little bit of gas to get it to start) run it at 2500 rpm for 30 seconds, let off and see where the idle is. If it's at 700 rpm its good, if its not, adjust until it is at 700 rpm.
Shut the truck off and wait about 30 seconds, restart and run at 2500 rpm for 30 seconds, see what the idle is, if it's at 700 rpm shut the truck off and reconnect the IAC, If not repeat the adjustment procedure.

I found this procedure in Shop Key after .9 volts gave me an idle that was way too high. I did this and it runs right at 850-900 rpm at a warmed idle

 

[shadetree]

A vacuum leak will give the same symptoms. Make sure all connections, hoses are solid. Don't forget the PCV valve. If it is not working correctly, it will cause idle, stumbling problems. Shaking to see if it rattles is not a valid test. Replacement is.shady

 

[almostclueless]

Check the wiring to the TFI module. This can be problematic to check, as I've read the wires run sometimes run inside a braided shield....one option is to connect one test lead to the shield, the other to each wire to be checked and flex the TFI harness.

 

[Rangermilitia]

thank all of you for the ideas. i'll try em out as soon as possible. shcool and work takes up most of my time. i did move the idle screw to bandaid an earlier problem.

 

[Bryan22]

Sounds exactly like the problem i've been having with my ranger... let us know if you figure anything out. So what if the "idle" screw is set out of range? would this mess with the tps and the way the truck runs?

 

[Rangermilitia]

aaahh

i have tried everything listed so far and nothing is fixing the problem. now what is happening is i am getting a pip (Profile Ignition pickup) code. and the truck will intermittently shut off while under a load, accelerating. i notice that the rpm gague drops too which leads me to suspect a problem in the wiring or some component that makes the pip loose contact to the eca. any ideas??

 

[almostclueless]

The PIP malfunction and the tach dropping when it dies are right in line with tfi related problems (the tfi module, the compuer, and/or the wiring in between).


I'd have a look at the page here about tfi diagnostics

 

[Rangermilitia]

its kinda weird...

i have checked all of the wiring.. traced the green/yellow wire from components to eca! all seems fine. i hate intermittent problems.. i replaced my distributor and the tfi module recently. i did however buy a cheap-o kragen distributor.. i'm a little weary about it. but it runs the same as if i had my original one in it. this is getting very irritating.