TraviZ

iTrader: (2)

i recently b ought my first volt meter, but i dont know one thing how to use it. its the yellow analog kind. i need to check my voltage through my TPS to figure which one is the adjusting voltage wire. how do i do this? which setting do i set my volt meter at? and am i right when i stick the red prong into the wire socket of my TPS, and the black wire is grounded?

formula350_87

I assume you bought a miltimeter. It can measure voltage in volts (V), current in Amps (A), and resistance in Ohms. When you measure volts make sure that the selector is in position that relates to voltages (V). If you have it set for Amps and measure voltage it will short it.

Now set it to something above 12V, let's say 15V. It means it can measure voltage up to 15V. Now, if readings are too small, let's say 1.5V you can change the range lower (let's say to 6V). Give it a try. Again, just make sure that it's NOT set to measure Amps!!

Two wires: black - ground. Connect it anywhere to the chassis. Red - connect it to the point where you are trying to measure the voltage.

Good luck.

ME Leigh

Just a hint, read the directions......

TraviZ

iTrader: (2)

their was no directions with it,

and so i set it to the 10 DCV?

because i need to check for aprox 1v and when its WOT, it should jump to about 4.2volts?



if you know much about TBI tps, do you know which wire is the one that changes voltage? then i wont have to test these three wires lol

formula350_87

I don't know much about TBI. However Here is a schematic for your car. It's Fig.41 in here:
http://www.autozone.com/servlet/UiBr...3d80163fb5.jsp

Throttle Position sensor is in the bottom left corner. I guess you have to measure the voltage between black and dark blue wires at the sensor. It seems to me that black wire is ground in the schematic.

Connect black wire from the multimeter to the black wire at TPS. Then connect red wire from the miltimeter to the dark blue wire at the TPS.

Setting multimeter to 10VDC should be fine. If the needle goes all the way to the right change it to something greater than 10VDC. However if it happens it would mean that something is not quite right with the TPS.

TraviZ

iTrader: (2)

ok well i turned the ignition on, and i did the white wire first, and yes its a nice 5v at all times, and tbe blue wire. i get no reading.

it says it should jump up to 4.2-4.7v at WOT, but how do i get it to register a WOT reading?

ShiftyCapone

iTrader: (7)

You need someone to press the pedal down all the way for that.

TraviZ

iTrader: (2)

i just pulled it open manually, and nothing happened.

TraviZ

iTrader: (2)

hey actually, all i need to know is if that blue wire reads that voltage at WOT, if anyone knows if the TPS reads 4.2+ volts at WOT that would be great!

formula350_87

There is no white wire at TPS. It has Black, Dark Blue and Gray.
If Grey is what you refer to as white then nothing will change. You have to measure at the arrow of the potentiometer in the schematic which is Dark Blue.

Measure between dark blue and black.

TraviZ

iTrader: (2)

ok well it looked white to me lol

but ya i been trying the blue wire and i get no reading at all , i tried all DC settings and the ignition is on.

red wire is connected to blue, and black is to black.

formula350_87

Ok,

Connect the multimeter between black and dark blue. Slowly open the throttle from fully closed to wide open. Whatch the voltage changing (not jumping) from almost 0 to the maximum - almost 5VDC. If it does not change:
1. You have bad TPS;
2. Connector from wiring to TPS is not making a contact. Try to clean it and reconnect it again. If the voltage stays at 0VDC all the time look at the connector contacts at blue and grey(white) wires. If it stays at 5VDC all the time. Check connctor at blue and black wires.

formula350_87

When you say nothing at blue wire. Does the needle move at all? May be even to the left?

TraviZ

iTrader: (2)

no it does not move at all, the connections are clean.

could it have anything to do with my speedo cable being disconnected (vss would have no signal either)

and if i have a bad TPS, what are the side effects?

dimented24x7

iTrader: (2)

Havnt read the whole post but you need to back-probe the connector with it hooked up to the tps if your adjusting this way.

TraviZ

iTrader: (2)

what do you mean?

all i want is the voltage of the blue wire at closed throttle, and at WOT, i need to make sure im making at least 4.2+ volts at WOT, the problem is, im getting no signal.

formula350_87

I guess it would be real hard to start the engine. If you manage to start it it would die the moment you open the throttle.

By the way do you read any code? Chilton's book says that 22 should be set (TPS volts LO). 21 is TPS volts HI.

Here is another way to check if TPS is bad:
1. Disconnect car's battery.
2. Disconnect the harness from TPS.
3. Set the multimeter to measure resistance (R). Use 1KOhm range. Short red and black multimeter wires to check if it is working. Needle will swing to the right. Remove short.
4. Connect black wire to the TPS contact where black harness wire used to be.
5. Connect red wire to the TPS contact where dark blue harness wire used to be.
6. If TPS is good then the needle would move when you change throttle position. If it does not move at all then TPS potentiometer is bad.

TraviZ

iTrader: (2)

car runs fine and no codes except vss (lol)

i will try that later and come back with results.

formula350_87

I wonder if you were not making good contact between multimeter and blue wire all along?

Anyway let's see what the resistance is.

dimented24x7

iTrader: (2)

From your first post it sounded like your jsut sticking the probes in the connector for the tps with it disconnected. The blue wire is jsut an input wire to the ecm. There is no voltage at that wire. With the connector hooked up to the tps, insert two small sewing needles in the back of the connector where the wire enters in and stick them between the wire and the housing and push them in till they bottom out. One will go in the ground (black) the other into the input (blue). As the position of the tps changes, the voltage at the blue wire with respect to the signal ground will as well. Higher throttle will be at a higher resistance and the voltage drop will be greater (higher voltage). Lower throttle will be at lower resistance and the voltage drop will be less. The third wire is just a 5 volt reference so there will be const. 5 volts there with the key in the 'on' position. If you get around to it, get a digital meter from Radioshack or something. Even a cheap one will do. I was never too keen on the analog needle type.

TraviZ

iTrader: (2)

well actually i was just sticking it into the prong lol

i feel retarded. i will test tomorrow with sunlight

ede

you aren't going to get a lot of use out of an analog meter. invest in a DVM. fluke makes a couple of good ones.

89V6FBIRD

You don't really need to invest in a digital volt meter... unless you call $2.99 an investment. I got this one and it works great!

http://www.harborfreight.com/cpi/cta...emnumber=30756

dimented24x7

iTrader: (2)

If your jsut going to use it for small stuff the 2.99 el-cheapo would probably be fine. Lord only knows how long itll last but if you dont use it much it should stick around for awhile.

JediNemesis

I can't see any reason why it wouldn't, but I'd like to make sure. Does this method work as well as checking the voltage? That is, is there any reason that I would need to check the voltage if the resistance checked out?

Thanx,
Will