This is topic tps sensor in forum Tech Talk at Northern California Ford Owners .
To visit this topic, use this URL:
https://californiafords.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=020761
Posted by Duncan Motors (Member # 7045) on
:
what would the make the tps sensor peg out at a constant 5 volts changed 3 sensors still the same . computer?on a fox. helped some folks do a conversion found some grounds not hooked and fixed but still the same.
Posted by CALIFORNIAGT (Member # 7845) on
:
is it a conversion?
Posted by Duncan Motors (Member # 7045) on
:
yes sir
Posted by CALIFORNIAGT (Member # 7845) on
:
the wire hanrneST <----- CANT SPELL lol can be wrong for that year comp? like 88 to 89 to 90 to 93 87 conversion to 88 2 89 can be wrong???
Posted by Duncan Motors (Member # 7045) on
:
all 93
Posted by CALIFORNIAGT (Member # 7845) on
:
can u be usein a comp for an auto tranny? when the car is a stick?
Posted by Duncan Motors (Member # 7045) on
:
a9l, car is a stick!????????
Posted by CALIFORNIAGT (Member # 7845) on
:
check this out bro
http://fordfuelinjection.com/Inject_your_horse2.pdf
Posted by Duncan Motors (Member # 7045) on
:
o poopy,,,! i read that whole thing but not one thing bout that tps sensor but plenty of other helpful information . i do apperciatte the help but the harness i got and the com are all compatable and now im 100 percent sure from reading all the info. but no trouble problem specs, just fuel inject swap info but thanks for the help! any othe cool links?
Posted by turbo50 (Member # 6700) on
:
Gonna have to pin the harness out.
Posted by Duncan Motors (Member # 7045) on
:
all 3 wires go straite to the com right?
Posted by turbo50 (Member # 6700) on
:
quote:
Originally posted by Duncan Motors:
all 3 wires go straite to the com right?
Yup, through the harness.
Is the MAF plugged in when checking the tps voltage?
Posted by turbo50 (Member # 6700) on
:
Id bet you need a new ecu or check the ground on it.
You are probably having ground loop issues with the eec.
Posted by Duncan Motors (Member # 7045) on
:
yeah mass hooked up, there was a unhooked ground at first but found and fixed that at the ecu,but still the same,what about the mass flow tho hooked or not one of those wires loop through ?
Posted by Duncan Motors (Member # 7045) on
:
harness looked good even wraped before feeding it through the wall but will check pin test at com and then new com thanks that was what i was thinking but just had to hear a sec opinoin,
Posted by turbo50 (Member # 6700) on
:
If the grounds are good then bad EEC. The EEC has a type of internal voltage regulator in it and has reference voltage feeds and such. The EEC has a signal return ground loop voltage deal and when it fucks up you get crazy shit.
The gurus on here know this in depth but I can tell you it is probably a bad computer or the wrong computer.
Posted by turbo50 (Member # 6700) on
:
Also what readings do you get from the harness, key on with the TPS unplugged entirely?
Posted by turbo50 (Member # 6700) on
:
Now that I read this more and I know you are a shop because I have been there I am going to ask a silly question.....what COLOR wires are you checking for voltage across?
You are going to get 5 volts across the orange and black at all times key on.
Posted by Duncan Motors (Member # 7045) on
:
im checking the green wier . cars runs i was tryin to set the idle then set the tps and when i probed it i got 5 volts ! wow
Posted by Musttanguy (Member # 2251) on
:
Read my response in GENERAL TALK
5 volts is correct for reference voltage(orange wire) Voltage has to reduce coming out of TPS as it is a potentiometer and shoulod be about .97-.99. If you have already swapped TPS sensors and are seeing your 5 volt reference still, pull the green wire from the connector and test return voltage. if still 5 volts bad TPS, if normal test green wire going to computer as this should have NO voltage (green wire unhooked). If you see voltage here you are feeding voltage back through this wire and will have to search this out 1 step at a time.
Let me know if I can be of help
Posted by Duncan Motors (Member # 7045) on
:
i think the people not havin the ground hooked up tweeked the computer before i fixed it , did a pintest no shorts or drop in ohms , tried another computer and that was it! thanks everybody that was good response time and a lot of helpful information! thanks again.
Posted by JohnB (Member # 969) on
:
quote:
Originally posted by turbo50:
Now that I read this more and I know you are a shop...
Make sure you kick the website some $... ![[Wink]](wink.gif)
Posted by Duncan Motors (Member # 7045) on
:
the computer blew out again right on start , but not while key on engine not running, it showed the right voltage then , but as soon as the car was running voltage now at 5 again in green wire. turned engine off and and checked green wire voltage with key on engine off and now stays at 5 volts no matter what ,im goin to get a electric diagram and do some homework and trace everywhere the three wires route.im going to check what mustang guy said but i did that with the new computer and checked out ok but as soon as start up occured went strait to 5 volts.so now ill check that again
Posted by JohnB (Member # 969) on
:
Make sure the ground for the FI harness is good...
Posted by Musttanguy (Member # 2251) on
:
Yep, insure you have a good ground, this will be right below the computer opening and should be 1 black and 1 exposed wire on an eyelet which is secured to the metal with a green self tapping bolt. The signal return will go directly back to the computer. Leave the power wires to the TPS hooked up EXCEPT pull just the green wire from connector (computer side) and check for any feedback voltage.
It doesn't seem as though there is a problem with supply voltage, check to insure it is 5 volts (same supply wire that feeds TPS also feeds EGR position and MAP sensor)
I am definately going to say this is a ground issue.
Posted by Duncan Motors (Member # 7045) on
:
well cleaned all grounds and ensured all grounds are good ,solid,and well connected . orange is 5 volts, green 5volts, black is 5 volts,unplugecd every sensor no change , its like somthin is shortin out the computers and it is not a ground.one more computer to the dust tonight.same thing from the start. new com check voltage and good, 5 volts orange wire, green 1 volt. black 0 volts. start up car all wires 5 volts not a simple ground or computer
Posted by Duncan Motors (Member # 7045) on
:
the car is a 93 4 cly auto. converted to a 5.0 5 speed.still used the 4 banger dash and harness if that matters,everthing was a derect plug in deal. used a 92 ecu harness. 90 engine harness.found that one of the plugs for the clutch safty switch under ingagement was feeding the computer 12 volts back through voltage reference wires <the black wire on the tps>which i beleive is a variable ground the computer uses to manipulate the engine sensors,which i beleive was blowing the computer out on start up when the clutch was engaged.pulled out the plug from under the pedal assembly and tested , no more 12 volts through these related engine sensors at any time .i tryed another computer just a hand me down not sure if it even worked but it still does 5 volts all 3 wires . i disconnected the green wire while everything else still plugged in. computer side no voltage on green wire, sensor side 5 volts.umm just to say im eratated!if i ground the black wire voltage goes to normal but this is not right . i think i found the reason why the com blew but not sure if new com even works i def need help!please please please!
Fueled by Ford Mustang Owners
on CaliforniaFords.com