Any mutimeter should work. Set it to the lowest DC volts position and check/look for less than 1.0 volt--0.98-0.99 is best.

Dan

 

Does this only pertain to lightnings. I have an F150 and I just figured I'd check this out, and my voltage is reading 4.89....WTF. Plus I can't move the TPS at all, does this only pertain to Aftermarket throttle bodies? Thanks.,

 

No, this applys to F150s too. The 4.89v reading had to have been with the throttle at WOT---yes? It should read less than 1v at closed throttle and advance steadily up to 4.5-5.0v at WOT. The TPS may have to be removed and the bolt holes(2) 'hogged' out to give you room to rotate the TPS--just a little.

Dan

 

Ahh!!! Good old analog meters. You know of course how to read that properly I hope. You want to use the lowest DCV scale (looks like 10 by the picture) because it will be more accurate. Also that shiny strip (mirror) must be lined up with your eye so that you don't see any reflection of the needle in it, just the needle itself. I hope you can make sense out of that.

 

I went and picked up a digital multimeter...when it was at idle, it read 4.98.

How is this possible???

You're supposed to turn the key to the 'on' position right, but not start it?...I didn't matter any way, I started it and while in park, it read 4.98

 

please, someone help me out here. I know I don't have a lightning , but I do have a rough idle , and I think this may correct it.....maybe.

Is it possible that my sensor is bad?

 

When you have the meter hooked up does your volt reading change at all when you move the throttle lever from the idle positin to wide open? If it does not change you could have a bad TPS. Are you sure you are tapping into the right wires to get the volt reading? I can't even get a 4.8 or 4.9 reading on my L even when it is at wide open throttle postion. I checked mine last night and it was .950. I had to hog out the 2 screw holes so I could get the .992 reading.. If you had the TPS off make sure that it is on correct. There is a flat lever at the end of the throttle shaft that goes into a slot in the TPS. Bottom line is you shuold be under 1.0 volt at idle and you should be should some volt numbers variation when you move the throttle lever. Good luck..

 

I used safety pins and stuck them in to the back of the harness. Make sure that you are getting good contact, or else you will get a goofy reading.

 

so bascially yall drilled out the metal part on the tps.

 

i actually broke my tps and had to go buy a new one. no big deal it was only 20 bucks i think. it constantly read .7 and would not change. i broke it being the jackass i am trying to adjust it. i got it to .995 but it seems to idle a little higher now. odd

 

will it not being .99 hurt performance. i can only get mine to go to .85

 

Yes, mine were all plastic around the holes...

 

:o

TPS stands for Thottle Position Sensor. It is basically what tells the computer at what postion the throttle is located. If it is set wrong you will have idle/drivability problems. If it to high the EEC thinks you are at part throttle when you are not. It can close the IAC (idle air control- it thinks it's NOT at idle now) and add fuel basically bogging/surging the engine. If it is set to low, at WOT the computer thinks you are at say 7/8 throttle. Think about the fuel maps (a/f ratios) and it will make perfect sense why it needs to be set correctly. BTW, some TPS's are not very adjustable due to the way they are made. They don't have grooves that the screw is in therfore you have VERY little wiggle room.

Haven't really found out the specifics for the L's, but I know on the turbo Fords (SVO's, T-bird's, XR4Ti's, etc. ) it can really be a pain. As much as a .05 volt difference can cause the engine to idle roughly or cause weird throttle response.

Found the above on the first pg. of this thread...........................

Dan

 

I just checked my tps voltage and it was at .964v. Is this alright, or does it need to adjusted. I'm asking this because I had some serious problems this moring with my truck. It almost stalled out today leaving my house. I just changed the front two o2 sensors because they went bad. Another thing it does is when I hit the gas it takes about two to three seconds to go. Could it be a bad tank of gas or what?


P.S. Thanks to SVTBrad for letting me know about this thread!!

 

That voltage reading should be fine--the closer to 0.99v, the better but that's close enough.

You may have a dirty, sticking IAC valve. You can remove the two bolts from it(on the left side of the intake adaptor--with a shiny 'can' attached to it and an electrical connector) and soak the inside with a solvent--flush it out a few times. Put it back on and see if idles better.

How many miles on your fuel filter? If it has more than 10,000 miles on it, it may be clogged. You may have a vacuum leak(manifold bolts or hoses?) The air filter may be clogged?

You need to give us more info, btw. Miles, mods, more symptoms, etc.

Dan