TPS adjustment, has anyone done this before? - Snowmobile Forum: Your #1 Snowmobile Forum

ZRNUT · 01-14-2013, 12:40 PM

I've got my fuel mileage problem narrowed down to my TPS. which is out of adjustment. I have a 97 zr 580 battery less EFI. Has anyone ever done the fine tuning on one of these?
All the info i'm finding tells how to do the Ohm checks and how to adjust them with a battery in the system. I know the ohm's checks would be the same But how do you check voltage at the plug with out it running?
I have the old fuel rail that came off the sled and it was at about 6 o clock and the one on there now is at about 4 o clock.

**RJ Gleason** · 01-14-2013, 03:51 PM

Use a 9v battery to provide power to test with.

**kccats** · 01-14-2013, 05:53 PM

Didn't you have other injectors! I wouldnt mess with it, and swap it out!

ZRNUT · 01-15-2013, 07:11 AM

The other fuel rail i had was leaking that is why i replaced it. But the TPS on that one is still in the original place and it is straight up and down.

Where would i connect the 9v battery to? and do i do the volt. adjustment with the TPS plugged in and then just tap into the connections?

**RJ Gleason** · 01-15-2013, 03:23 PM

Attach the battery to one terminal and the other side to the black lead of the VOM. Use the red lead on the other terminal and verify voltage through the range of the unit.

ZRNUT · 01-16-2013, 07:31 AM

There are three wires out of the TPS so which one do i attach the power too?
I have found a thread from Blain that describes a how to. but he is using a A,B&C to describe the wiring. I did the Ohm's check on the Throttle and found that to be in the ranges that are described. But this TPS thing is a real head scratch er. Trying to do this right and not burn my motor down.

**RJ Gleason** · 01-16-2013, 07:37 AM

The center is the variable and the outer two are constant.

**kccats** · 01-16-2013, 07:47 AM

Just use the other rail and use the injectors from the good one!

ZRNUT · 01-16-2013, 08:13 AM

Thanks RJ ..
KC the other rail was leaking from by the pressure regulator that is why i replaced it. I would hate to start stripping parts off my one on the sled to try and rebuild the other one and end up with two that don't work. It would definitely be easier than trying to set this TPS. I was going to practice on the old rail to see what readings were coming off of it first and then do the one on the sled.

**RJ Gleason** · 01-16-2013, 12:06 PM

You can swap the pressure regulators too.

**kccats** · 01-16-2013, 03:12 PM

Thats just an O ring!

ZRNUT · 01-17-2013, 07:13 AM

It was leaking out of the fuel rail line itself. I thought it had maybe a pin hole or was cracked. it was where the fitting is by the regulator. I didn't look that close as i had the extra rail so i swapped it out. i will look it over tonight and see if i can swap out the fuel line and then just put that unit on.

ZRNUT · 01-19-2013, 05:01 PM

Did the test on the TPS. Here is what i found. Tested between black n red had 4750ohms the did the test between white and black at idle it was at 702 ohms and at wot it was 3940ohms.
I loosened the screws and adjusted the idle to 850ohms as the post from Blain states. i then did the wot and it was up to 4050. he is saying that it should read 4250 or higher. So now what do i need to do/ As i raise the idle ohms adjustment upward then my wot ohms reading increases also. to get to the 4250 ohms i need to have the idle ohms at 975.
Does raising the resistance lower the fuel richness? By being at 702 before that would make sense why my sled was so hard on fuel.

ZRNUT · 01-19-2013, 05:03 PM

KC i looked at the old fuel rail and i looks pretty bad. i tested the TPS on it to see how it was and it is way off the numbers that Blain posted so i think it has a bad TPS

ZRNUT · 01-20-2013, 08:55 AM

Anyone? Help with these numbers?

**RJ Gleason** · 01-20-2013, 03:51 PM

If the throttle cable is stretched, you would have a lower reading at WOT.
is there any way you can see if you can take it up a bit and see if that helps.

ZRNUT · 01-20-2013, 05:05 PM

Quote:

Originally Posted by RJ Gleason

If the throttle cable is stretched, you would have a lower reading at WOT.
is there any way you can see if you can take it up a bit and see if that helps.

i was able to reach in and check for play on hte throttle and it is bottomed out at WOT. I guess my biggest concern is by raising hte ohhm's reading on the idle brought the WOT reading up but am i making it richer or leaner by doing this?

**RJ Gleason** · 01-21-2013, 01:22 AM

As I see it, the only best way to test this is some plug chops to verify and then step back a bit if necessary.

ZRNUT · 01-24-2013, 07:38 AM

OK from what i have been researching if i raise the resistance or Ohm's then i will be reducing current flow thus leaning out the fuel mixture. Lower current would in essence slow down the injectors and in turn let less fuel travel through them.
Does this make sense to anyone?
We are suppose to be getting snow here tonight and again on Sunday and then again on Tuesday. If any of these put a few inches on the ground i will be able to get out and test this out.
I will do some plug chops to see if my plugs look good.
I will report back what i find out.

**RJ Gleason** · 01-24-2013, 07:43 AM

That would be correct.