Xophertony

yes i searched.

i installed new TPS. now car has surges at low rpm worse then before. when i installed the tps it seemed fine (car was warm when i tested it)

what do i do? how to i alighn it properly? is there a method, or is it guess and check? the sensor came with no instructions.

87blueracr

take a multimeter, and use that til you get .37V you got to play with it for a little with it being just loose enough to move but not fall when you let go of it. remember red is positive and black is negative.

Xophertony

so at idle it should be at .37v ? is that resistance? where do i set the multimeter? can i use a digital one for this?

LinuxGuy

iTrader: (1)

Um, 0.37v is way to low for the idle TPS setting. 0.54v to 0.56v is where it should be at. At wide open throttle it should be over 4.0v (or was it over 4.2v?).

You can use a digital multimeter. There are three wires connected to the TPS. You will have to cut some pieces of wire to go between the pins in the connector and the pins on the TPS itself so that you can clip onto the wires with the multimeter. I can't remember which wire is which. I usually just hook the multimeter up to the top two, and most of the time I get negative voltage readings instead of positive, so I swap the wires around.

87blueracr

maybe it is.45, but i know at wot it should read about 4.5v. you can't set a multimeter for voltages, you must read the voltage on the multimeter, and yes a Dmm is recommended as it is very easily read and used

2_point8_boy

A DMM is REQUIRED because if you use an analog meter it'll load the circuit and you'll get a false reading. Also, you COULD damage the computer because analog meters have a very low internal resistance and pull extra current through the circuit that the ECM might not have protection for.

Unless you are specifically told to use an analog meter by a factory service manual, use a Digital one just to be safe.

But you should be able to backprobe the harness (that's what I do) at the top 2 pins. you should get 0.55v at idle and >4v at WOT.


Jeff

87blueracr

it doesn't specify voltage reading on the haynes manual(atleast not that i could find today. i am a electrician as well as a machinist, i think that if the navy found me safe to work on electrical components on ea-6b's, f-14's, and f-18's to name a few, that i know a litttle about electricity. there is no difference as to how the multimeters work, the only difference is that one is digital the other is analog. to take a voltage reading, you need to have it hooked up, therefore you are only monitoring the voltage and amperage not sending a current from the multimeter. both are safe for that aplication, so someone needs to go back to college and learn about electricity as i had to do(the only reason that i don't have a college degreein electrical engineering is that i need to go take the general courses needed for all degrees)

Xophertony

to cut the pissing contest short i will be UNPLUGING the sensor from the harness as to isolate it from any posible damage. also i will have no need to strip wires that way.

thanks for the input guys.

87blueracr

that is what i thought that you were gonna do to begin with. if you can isolate something from unneeded risk, do it. if not, try to make the risk the least you can that way the numbers are always in your favor

2_point8_boy

How are you planning to get voltage to it and from it with it unplugged? You have to have it plugged in to set it. there's just no other way to do it accuratly and quickly. You'll spend all day unplugging it, moving it, plugging it back in and testing it over and over again until it's right. Plus, you have to have it plugged in and powered to get the reading from it.

87blueracr

not if you know the incoming voltage and amperage, you can find the propper resistance and set it by that. anything that changes the voltage like that so variably like that normally is a variable resistor. that voltage will have a corresponding resistance, use the ohmmeter to find that correct resistance!

molopaa

iTrader: (1)

No offense blueracr, but if you really are an electrician in the navy and work on different aircraft, then I wouldn't want to be a pilot in the US navy.

I mean it's basic stuff, the difference between an old analog meter and a digital meter. The old one's have very little internal resistance and the will draw lots of current. Focus on the word DRAW. They will not feed any current into the circuit when measuring voltage, that's true, but that's not the issue. The will put a signifigant load on the circuit being measured and when dealing with modern circuits, they can be damaged. The digital meters have internal resistances probably measured in mega ohms and put little stress on ciruicts.

Have you ever wondered why you should't use an analog meter to take readings from an oxygen sensor?

kretos

search around the boards, everyone is tild to use a analog multimeter, unplug the tps, then use the analog on the ohm resistance settings to figure it out

87blueracr

first why would you even want to take a reading on the o2 sensor, they are like 16$. second i deal with only digital multimeters because they are more accurate, and when dealing with aircraft, .01 volts tells the difference between a good circuit and a bad one. in school we were always taught that both work the same way and that eithor one is good to use, just that the digital is alot nicer and more accurate. nothing to do with internal resistance. by the way if you are worried about internal resistance, try a different scale!

molopaa

iTrader: (1)

You're missing the point, but no point in arguing.

The reason you would measure the voltage off of an oxygen sensor is: The fuel ratio is determined by the voltage generated by the sensor -> A multimeter can be used as a display, when wanting to know if you are running lean/rich. It's a crappy way of doing it, since the reading changes so rapidly, but.....

Xophertony

so does anyone know the resistance it should be set for?

TomP

Resistance? Nah man, you need to measure the voltage. A digital meter is $12 at Radio Shack- oops well they used to have a $12 one, now it's a $20 one - http://www.radioshack.com/product.as...D810&hp=search (or search for part 22-810 at radioshack.com if that link wont work) but you could probably find a $12 one somewhere.

While you're at Radio Shack, pick up a set of their alligator clip jumper cables- http://www.radioshack.com/product.as...Fid=278%2D1157 (or search for part 278-1157 on radioshack.com).

Then, engine off. Unplug the TPS. Wedge the alligator clip jumpers between the TPS sensor and the TPS connector, so the sensor acts like it's still connected to the harness- but thru your jumper cables.

Then put your meter on DC volts. Stick one lead from the meter to the middle terminal of the connector. Then stick the other lead to the "upper-most" terminal of the connector.

Turn the key to on (don't start the engine, no need to). The meter will show a number. Loosen the torx screws of the sensor and swivel the sensor back and forth until you're at 0.55 volts, plus/minus 0.05 volts.

That's from the GM Service Manual. I'd NEVER use a Haynes book for anything like this.

Find more info in thirdgen.org's techcentral area, here's the link to make things quick: https://www.thirdgen.org/newdesign/tech/tpimod2.shtml Roll down the page until you see the paragraph for TPS adjustment- and don't follow the spec listed, it's for v8 tpi and not for our v6's.

And I'll attach one of my infamous quick-pictures of how you'd do the hookup. AND I'll even give you a link to the original "quick picture" message https://www.thirdgen.org/techbb2/sho...hreadid=180325

HarborFreight.com used to have cheapie $8 digital meters; I bought one and used it for years; it did OK for a cheapie!

2_point8_boy

Glad someone else knows how they work and the dangers of using an analog meter on vehicles.

Because on some cars the sensor is like $150.

Anyway, TomP, good picture on how to do it.

Xophertony

i used an analog meter today, simply because i know bugger-all about how the digital one i have works. i got it to .55v but i am still getting a code 22. car seems to be running spot-on. i think i will pick up those aligator clips from radio shack tomorow and do it properly. thanks for the idea tom.

Xophertony

well, finaly figured out that digital one. and the sensor, when its adgusted as far as it can go in the right direction gets a range of .26v-3.xxv. so i ordered a new one from napa (free of course) and will pick it up at 4pm today and give this another go.

87blueracr

remember wot should be above 4V and idle should be about .5V

Xophertony

yes, that is why i ordered a new one. to correct that little problem. i am taking off to the napa now, i will let you all know how it goes.

87blueracr

sounds good to me man, keep us up to date!

Xophertony

update.
well i picked up the new one and put it on in the parkinglot. i just eyeballed it so i could drive three blocks to my dad's house, get the tools out and do it for real. well i get home and it was at .47V dang i was close, i teeked it for a few seconds until i had it at the optimal .55V.

current range .55V - 4.38V. perfection. car runs like a champ too. no afterfireing. seems to have a good mixture. the next cold start will be the surefire test.

thankyou everyone for the help.

Xophertony

well. did a cold strart. waited till around 11pm, car had not run in 4 hrs and shazam! fired right up with a smooth even idle. i am thrilled.

87blueracr

that's what i like to hear! good job man!