TPS adjustment

Need help folks, ok i am using rob Lentinis method of adjustment. my voltage readings stay at .5 volt with no fluctuation when turning tps switch, does this mean i have a bad switch. i am looking for a reading of .370 to .400, i must be missing something, do i need another more sensitive meter, any ideas will be greatly app.

Key on
Throttle closed
Reading at red/white wire.

Sorry, yes key on . red & white wire, side stand up. tank off. lentinis instructions to the t which includes kill switch on as well.

With the probe(s) attached - roll the throttle. You should see the MV reading go up as the throttle is rolled.

If perchance it won't drop below the 500MV you are seeing, make sure the fast idle (choke) lever is in the off position and that there is free play in the cable.

It sounds like something is holding the throttle open a little bit - maybe.

IBMWR.ORG oil head tec pages. "zero=zero" method, yes i tryed rolling throttle as to see if ther would be any voltage changes. none, throttle stop screw backed off so as to see about1/6 inch. maybe my meter because it only go down to 200m, dono. really stumped. ill try installing tank with fuel pump hooked up with kill switch on. also, the fast idle cable is loose.

You are measuring voltage?

ratze said:

IBMWR.ORG oil head tec pages. "zero=zero" method, yes i tryed rolling throttle as to see if ther would be any voltage changes. none, throttle stop screw backed off so as to see about1/6 inch. maybe my meter because it only go down to 200m, dono. really stumped. ill try installing tank with fuel pump hooked up with kill switch on. also, the fast idle cable is loose.

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When you said "200m" I immediately thought you were checking resistance. When you said no voltage change rolling the throttle, I was thinking resistance doesn't change much but voltage should. Me bad if I'm second guessing you but I am at a loss for words to help you.

I have seen enough bad TPS but you really aren't describing what I would expect.

There is always the simplest route, if the bike ran OK before, the problem is new, maybe you? Multimeters can be a bitch. For me, I have about 7 of them and when I pick one up I haven't used for awhile, I screw it up until I remember the symbols, the ranges and the lead connection for each.

Yes i am shure your right, something iam over looking. but my meters DC volt scale go'es from 500volts down to 200m, which i am assuming is 200mili volts. how would one check a tps switch to verify weather good or bad.

Can you post a picture of your meter?

I'm getting you dude and I'm getting confused. If I saw a picture of the meter you are using, I might come up with something absolutely brilliant.

Then again, my hockey team is losing again and I am getting depressed so my suggestion might not be much help.

Oh, I think I just got it.

Like I said, some of these meters can be a real challenge if your like me and forget to take your medication. Does yours look like this?

Cant post a pic but the meters a INNOVA 3306, Equus.com,,,,maybe thats it, iam off my meds. havent riden in a week. (digital meter) REDWINGS,,,,,

"Go Redwings" just rubs me the wrong way.

Historically, they have always been second best. Only Montreal has been better but damn, they are a fine hockey team.

OK, so I found a picture: Top left quadrant you should be at "20" with needle pointy thing. Black lead on "Com" and the red lead on the far right. I don't know the color of the wires as I'm really bad color blind but pin #2 and pin #1 should be right and you should see the voltage about where you want to be.

If you have your leads reversed, no big deal, you will get a negative voltage sign. Voltage will still be what it is, just in reverse.

Carry on and have fun.

ratze said:

Need help folks, ok i am using rob Lentinis method of adjustment. my voltage readings stay at .5 volt with no fluctuation when turning tps switch, does this mean i have a bad switch. i am looking for a reading of .370 to .400, i must be missing something, do i need another more sensitive meter, any ideas will be greatly app.

Click to expand...

It seems to me like you're measuring the wrong spot or your meter is somehow defective. If you roll the throttle and there is no voltage change (truly) your bike wouldn't run. You want to measure the voltage between the two end pins on the TPS. Before the procedure, could you ride your motorcycle?

First the obvious: You need to use a digital volt meter, not an analog (moving needle) one.

Then, you really ought to have a good-enough unit that will display three decimal places (numbers to the right of the decimal point). Two decimal places will get you in the ball park; but that's also a sign that it's accuracy may not be so great either. Without a good meter, you'll just be spinning your wheels.

One more point that may be overlooked (I've seen somebody do this...) - the connector must be connected ON TO the TPS!

The measuring point is the red & white wire at the "rear"-most of the connector; this can be very difficult to get a good contact on without damaging the wire somewhat - use a clip holding a very skinny needle, or rig up a similar probe.
The other side of the DVM must go to a good ground; typically this is the brown wire on the underside of the throttle body, but can be any good solid frame/chassis/battery connection. Note that the closer you are to the TPS, the more accurate your voltage reading will be (due to the voltage drop that a longer path may cause).

A reading that does not change when moving the TPS is typically one of two things: either you're really NOT making good electrical contact, or the TPS has a real issue. The TPS is not a switch (unless you have an older K bike); it's a pair of variable resistors (also called potentiometers or rheostats). Internally, the element can break or get corroded, but this is fairly rare for our bikes as far as I know. I'd suspect test setup error (even the DVM leads can be open inside the insulation) or user error first.

I have a short length of speed wire (used for wire wrapping prototype circuit boards in the old days) permanently installed on the right most pin of my TPS. It's very fine wire and can be just bent a bit and captured in the connector itself without damaging any wire insulation by stabbing it with pins etc.

You can also just peel the insulation of a 22 AWG or 18 AWG wire, separate the strands and use one strand to do the same thing. Unclip the TPS connector, capture that strand on the correct contact and gently push the connector back on. Clip onto that wire, ground the other end of your meter, set it to the lowest VDC scale as long as it is greater than 400 milli Volts and you will get an accurate measurement.

And as Pauls1150 said, connector in (connected to TPS) and key ON.

Very pleased to report that i just put 75 miles on the bike, the zero-zero method works with plug change. I went down and purchased another meter, set the tps switch to .010 and then the stop screw to .385volts. the bike runs great with no surging issues, a big thanks go'es out to rob lentini for all his research. thanks again folks for all your responses.

The cruiser has been transformed into an RT, 1100S sixspeed gearbox and clutch assembly. ect, ect,,,,,

ratze said:

I am new to site,,,,,,please excuse.

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Excuse what?

Glad you got your problem figured out.
I think you should post more pictures of your unique bike!

UNIQUE indeed, she runs with the harley big twin all day long. not that that means anything,,,,,here you go.