98 zr 600 efi idle irregular - Snowmobile Forum: Your #1 Snowmobile Forum

djhammy · 02-13-2013, 10:29 AM

I just got done doing a topend rebuild, I had noticed this before the rebuild and I had the throttle body out and cleaned it pretty dang good, I also was trying to figure out how to adjust that tps sensor since it swivels a bit before you tighten it in place, issue is that the idle wont go low enough to have a steddy idle, so im thinking the coil springs that open up flaps might need to be replaced or somehow wraped around another time, that or the tps on the right side of throttle body is ever so slightly off. it starts and runs great till I hit the throttle a bit and I have to take a scew driver and push down the lever by springs in the middle of throttle body to close up flaps....you guys got any ideas?

djhammy · 02-13-2013, 01:33 PM

I think its called the servo arm ( where throttle cable attaches ) if I push down on it, I can get it to close the butterfly (flaps) and then it idles fine, but I have to keep manually doing this after throttles is opened... so im still stuck on weather in need to mess with the coil springs that open the butterlies, or maybe I need to re- adjust that tps sensor, or heres an idea even tho I cleaned out throttle body maybe I need to take some sand paper and go around them butterfly flaps lightly, its hanging up or gunked up or springs are too weak to fully close the butterflies up.... anybody got ideas

djhammy · 02-13-2013, 08:05 PM

I messed with the adjustment of the tps so it matches right up to where throtle lever sits but even then I can still take a screw driver and push that throttle lever closed more.... my experiance with cars tell me it should freely close all the way by itself, I do know though that there will be a bit of air flow allowed for it to idle, I'm anoyed. Neighbors complain about the sleds noise since there living rooms on the other side of my garages wall, so I guess I have to wait til tomaro and pull it outside and f with it then, just wanting to know if u guys gotta similar sled and if u try to push down on your throttle lever will it close more yet, then ill know if my throttle body needs more attention.

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**kccats** · 02-13-2013, 10:17 PM

If you are talking about the Throtle Position sensor, if you have loosen and moved it, IT IS JUNK!

djhammy · 02-13-2013, 10:49 PM

Are u sure were talkin about the same thing, I removed it before and ran fine, this is on the far right lower side of throttle body, 3 wires, coil spring switch that moves with throttle..... I think I have build up by coil springs on both sides of throttle cable cuz if I full throttle and release it closses throttle all the way but I rease throttle slower or at medium throttle it gets hung up a bit and doesn't fully close

**kccats** · 02-14-2013, 07:18 AM

Yep

djhammy · 02-14-2013, 07:58 AM

well how? seems odd that a part cant be removed and put back on, is it a trick of turning it/ winding it up a bit and somehow holding it there before putting it on, that would make sense....

djhammy · 02-14-2013, 07:59 AM

I wonder if this is a tps issue, is there a way to unplug or bypass it just to see if it makes a difference

93Wildcat700 · 02-14-2013, 08:05 AM

Kc cats is right you should just not mess with those.

No there is no way to bypass your TPS its like a Cam position sensor that is what your EFI box is using for timing.

Even if you would have left it on the sled its not recommended that you even move it at all.

You are onto something with the way that it goes back together but i cannot personally tell you how that goes. If you were able to figure out how to properly get it back installed you could adjust it back to stock using a Ohm meter but like you said it seems like a PITA to get it linked back up right.

Worst comes to worst you buy new throttle bodies on ebay with a tps and don't move it. but im all for not spending money so keep trying to figure it out.

djhammy · 02-14-2013, 08:13 AM

I wish I would have known this about not removing it, allways somthin over here, well if anybody knows how these get installed, let me know, ill do a couple of dif thing like full throttle then poping it on and see what happens, and yup belt will be off when playing with this kind of stuff, don't need my sled taking off through a wall...

93Wildcat700 · 02-14-2013, 08:29 AM

That the thing im sure it MAY be possible but even the Manual states you have to replace the entire throttle assembly. See what i have attached

djhammy · 02-14-2013, 09:22 AM

Ok. Well I'm still not gonna just give up on it, if cat didn't want the dang thing removed the should have designed it dif not makeing it easiest to unhook it, the dang plug wont pop off with stearing rod so close ect.... sureley sombody knows how they go in, ebays loaded with throttle bodys for sale but don't have tps or injectors in for $100+ kinda rediculius
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93Wildcat700 · 02-14-2013, 11:04 AM

Maybe this will help. See the part i BOLDED

TESTING TPS
If you think it is the throttle position sensor, you can check it with an ohm meter. The TPS has 3 wires/pins and I can't remember which is which, but you can figure it out easy enough. Call the wires/pins A, B, and C. The wires connect to the TPS at the connector. Unplug the connector and hook a meter between 2 of the pins on the TPS. (on my sled I couldn't unhook the connector, so I cut the wires and re-soldered them back together after getting it set). This is where you figure out which ones you care about. A-B should be about 850 ohms at idle and go to about 5000 ohms at full throttle. A-C should read about 5000 ohms no matter what the throttle position. B-C you don't really care about but will be have a high reading at idle and go to a low reading at full throttle. First, if A-C reads open or more than 15% from 5000 ohms then the TPS is likely shot, but you would probably get a fault on the computer. Next, when you open the throttle the reading for A-B should increase smoothly to 5000 ohms at full throttle (+ or - 15% all readings). When checking for smooth operation between A-B, I use an analog meter with a needle because it is easier to see a dead spot in the range as the needle will jump. The TPS is the main sensor the computer uses to determine how much fuel to deliver. If the readings are off, the engine will run rich or lean throughout the range. If A-C checks out and the reading for A-B is smooth, but the idle and high throttle readings are off, you can try adjusting it by loosening the 2 screws a bit and rotating the TPS to get the readings in tolerance. Do this at your own risk as Arctic Cat says not to mess with it and replace the whole throttle body if the TPS is out of spec. Again Idle should be 850 + or - 15% (723 to 977 ohms), and full throttle should be 5000 + or - 15% (4250 to 5750 ohms). One note: when checking there can be cable slack that will not allow the throttle plates to open all the way and you should reach in where the cable hooks at the throttle boby and rotate the butterfly's full open when checking it. If this occurs you can see 850 at idle and get only 4000 ohms at full throttle with the throttle flipper, but 4350 ohms pulling it the rest of the way by hand. Before adjusting a TPS that was off 690 ohms at idle it was bogging under hard acceleration.

You then read the center pin to the 0 volt pin with a good digital volt meter. the signal should sweep from about 0.6 volts to 4.00 volts as you open the throttle to wide open. There should be no jumps or drops in the wiper voltage. The TPS is just a three pin potentiometer (variable resistor) or voltage divider. It is nominally 5000 ohms total (5K). The variable wiper sweeps across the resistor element to tap a resistance value. The ECU makes a 5.00 volt reference voltage for all the sensors and the TPS is connected to this voltage. The +5 volt end is the high end of the pot and is the WOT end. The 0 volt end is the common terminal. As the wiper sweeps the pot, the feedback voltage is divided across the element. At closed throttle, the voltage at the wiper pin to common is about 0.6 to 0.7 volts. At WOT it is 3.9 to 4.0 or so. This reading would probably be different depending on the throttle body or carb setup and how much angular movement the shaft has. The test box that Cat sells has a 9 volt battery and a 5 volt voltage regulator transistor to make the reference supply. It then connects this to the TPS with the proper plug and has a test jack to connect a digital voltmeter to read the feedback. The TPS on the triples only affects the spark advance curve and gives the 3rd dimension to the curve, engine load. The other two are RPM and advance degrees. That is why the later CDI’s were called 3-D.
At WOT with 4.25 volts reading the pot is at 4.25 of 5 or 85% of full reading. So 85% of 5000 ohms is 4250 ohms reading from the wiper to the common terminal or 750 ohms reading from the wiper to the high or 5 volt terminal. With 5000 ohms and 5 volts reference, the reading is 1 volt per 1000 ohms.

**RJ Gleason** · 02-14-2013, 11:05 AM

Better to leave the belt on and put the rear up on a stand.
You don't need a runaway engine.

djhammy · 02-15-2013, 12:28 AM

well this is what I did so far... because there's only like 3 different rotates aprox in that sensor, prong on top prong on bottom and that rotates with the throttle, so first setting was like at 1/4 throttle/ 1 rotate, and I screwed down the sensor, now keep in mind this thing also swivels giving u more of an adjustment to get it just right, and I know this but just by pressing down 1/4 throttle and screwing it into place and matching the sensors swivel/angle to the rubs on bottom plug from rubbing on steering rod, and I started it, idled good, gave it a bit of gas and back down and sounded right, then gave it a bit more throttle and back and it went up and came down as I think it should, so tomaro I will prop up track first and try it high enough to engage clutch and if good I will take it on a test run, wish me luck!

djhammy · 02-15-2013, 02:41 PM

let me retrack my last statement...lol. the tps sensor only goes in one way, you ever so slightly open throttle to screw down tps. there is an adjustment only in the swivel of its mounting holes. I believe I have a dif problem, idk. I can get it running good, and revs up good but it return to a proper idle only works when I slam the throttle and let it slap back, so something is still hanging up the throttle butterflies (flaps) probably internal shaft or something in there, it gave me a migraine literally, or maybe that was the exhaust fumes, idk. im trying to find a local to look at it, or ill just end up buying a used throttle body with tps still on off ebay....

**RJ Gleason** · 02-15-2013, 04:54 PM

Does it do that with the throttle cable unhooked too?
Just trying to eliminate possibilities.

musicfreako · 02-15-2013, 07:18 PM

That's what I'm thinking. Take throttle cable completely off tthrottle body and see if butterflies fully close then.

djhammy · 02-15-2013, 07:39 PM

The cable is somthing I looked into, but there's a bit of slack and for spits and giglesi sprayed some pb blaster down the throttles cable tube. But the thing is I can feel it get hung up by maually moving that throttle arm, it feels as if its inside the throttle body, sound weird but same feeling as if your turning a bolt that's bent when threading in. But I did just unhook cable, and the cables fine, its in the throttle body somwhere, I hate when u fix one thing and then another.... well I ain't missin out on open trails in south east wi...lol.

**RJ Gleason** · 02-17-2013, 07:26 AM

It is very possible that the throttle rod in one of them is bent, you would have to separate them to verify though.