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Discussion Starter · #1 ·
When you guys are setting your TPS, the service manual says, "Let bike heat up thoroughly, then check."

Well I check the output voltage at 3 different times, here are my results.

Bike cold - .44
After running for 2 minutes - .58
After running for 7 minutes (coolant fan running) .65

Now I read about everyone adjusted theirs, but when, at what temp? If everyone is following the service manuals instructions then I should be in spec, correct?
 

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Humm... interesting.... I don't think I have ever noticed any difference with temperature.


What about battery voltage?... What is that looking like cold?
Sounds like an input fluctuation. Check input also... should be steady around 5v.

I mean lots of items will have a change in resistance and output with temperature, but I do not think I have ever noticed it on the TPS at all.
 

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Discussion Starter · #3 ·
Input was around 4.??v Battery voltage is good. I would imagine there would be fluctuation due to the fact the service manual states "checking while motor is hot"........

When have people made the adjustment? When the bike was cold??
 

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Discussion Starter · #4 ·
I'm gonna check the input voltage the same way I did the output and report my results. If that varies then ECU trouble??
 

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ECU or input wire or ground wire trouble.

Input should be between 4.75v to 5.25v with a fully charged battery (12.8v or more).

Should be the same while running also.


This may not end up being much fun to track down. But it is not usually terribly hard. Just takes persistency and knowing what to look for.
 

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Check the resistance on the TPS terminals for the blue + and brown - wire...???

standard 4~6k OHMs...

It maybe a bad TPS...???
His input is low... so he will have to check resistance on his wires first to see if that is where the voltage drop is. Bad part is that the wiring is shared on supply and ground and if there is a problem it could be on one of several legs of the wiring.

As many wires as this heap has, you would think everything would have it's own dedicated wires... lol...
 

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Check the resistance on the TPS terminals for the blue + and brown - wire...???

standard 4~6k OHMs...

It maybe a bad TPS...???
His input is low... so he will have to check resistance on his wires first to see if that is where the voltage drop is. Bad part is that the wiring is shared on supply and ground and if there is a problem it could be on one of several legs of the wiring.

As many wires as this heap has, you would think everything would have it's own dedicated wires... lol...
Have him check the reference voltage on the Air pressure sensor LB & BR/BK wire...should be the same voltage as the TPS LB & BR/BK wire...4.??v as he stated...

If the same voltage reading then it's the 0-5v reference circuit of the ECU...

The ECU is bad...Unless his F.I light is coding...Then it be a sensor malfunctioning open or closed short...???
 

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Discussion Starter · #9 ·
Let me give some more background on my issue.

Bike would run good and every now and again it would bog out at full throttle and then the next day it would be fine. Then ontop of that, it would not hot start worth a shit. When the bike is/was cold, it would fire right up and run good. Took it out a few weeks ago and it ran horrible, worst it's ever been, so that's when I decided to investigate.

The day before I started this thread I tested input and got 3.33v, I thought "ok problem solved ECU is shit". So next day I took the ECU out of my brothers KFX and my bike ran flawless. So I thought "I'll put my ECU back in to confirm it is a bad ECU." Put my ECU back in and bike ran fine, wtf?!? Check the input and that's when I got the 4.??v. So either I'm losing my mind and 3.33v was a bad connection on my needle adaptor, or the problem is the ECU and it just decides to come and go at is leisure. I'm gonna check my brothers bike and compare results, but I'm thinking the ECU is shit, and due to their bad rap for crapping out it makes it more beleviable.

Thoughts?
 

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Put his ECU back on your bike and retest.

Unplugging the ECU is kind of a reset for it... but not a problem solver.
So you can see how things could come and go....
 

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Bringing back old thread... But after i got all my enine work done i finally got my tps set. Runs fine. It starts and reads .58. Then goes clear down to .40 ( goes down bc finally gets down to idle which floats aroud 1600-2200..

Is this way to low??
 

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Bringing back old thread... But after i got all my enine work done i finally got my tps set. Runs fine. It starts and reads .58. Then goes clear down to .40 ( goes down bc finally gets down to idle which floats aroud 1600-2200..

Is this way to low??
The idle is problematic due to the possible bad TPS... the TPS internally has 2 brushes/like back scratch-ers if one or more are weak it can throw off your voltages...see pics..

I recommend you replace your TP sensor,
 

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Yes I would try to set it more like .62v and see if it still settles

Also with the engine off listen to see if you can hear the arm hit the stop. Could be cable related.
 

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.62 at what what rpm.. If i were to have a high or low idle thats gonna effect my reading...
 

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Idle speed has zero to do with it.

The throttle position is not affected by idle speed like a Carb is.

Set at .62 throttle closed and that is it. Does not need to be running.

For better understanding see my throttle body thread under important information.
 
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