High Idle Issue

[PNW Rook]

Hey everyone I'm working through a problem on a new to me 2008 Dragon 700 RMK high (3200RPM) idle issue . I'm thinking vacuum leak so this is what I've done for trouble shooting and just maintenance:
- new intake boot
- cleaned throttle body
- cleaned/rebuilt power valve
- o- rings on injectors
- cleaned and inspected reeds

Started it up........3200rpm's after a bit engine code 5 for exhaust temp comes on. It's for running above 3k rpm's for longer than 2 minutes, etc etc etc. Can't imagine that would have anything to do with cause of high idle.

So back to trouble shooting:
- sprayed throttle/ brake cleaner around engine expecting if their was a vacuum leak it would pull it in and raise the rpm's. That did not happen..... so no vacuum leak??
- I'm about to check out my TPS. Been on YouTube for videos and have a fair knowledge through YouTube university.
- I also read a review that the ECU was damaged done how. I have a 2009 800 dragon, if plugs match up do you think theirs any harm swapping the computer into the 700?

Thx any advice would be great, TIA.

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Okay I'm back with even more dead ends. I went through my TPS and came up swinging. I first tested the current setting, it was with in .002vdc so I almost didn't move forward. I decided to go ahead with my TPS testing. I first started with a baseline, I backed off my throttle cable and then my throttle stop. The TPS was sitting at .687vdc so it was off. I adjusted to .700 on the dot by rotating the TPS itself and locking it down. I then brought the idle set to .950vdc on the dot. I knew I had this licked. Put everything back together and pulled the rope. Boom.....right back up to 3200 rpm's. Crap I fixed nothing, again.....

I did notice the coolant temp sensor was not at the desired resistance. Desired 2.5k-ish ohms @ 68°f and mine was at 4+k ohms @ 54°f. I'm assuming that would show it to be extremely cold and then would it ever show it to be warm? Don't know.

I also checked my spark plugs, they are not showing a lean issue situation at all. However I'm only running for maybe 1-2 minutes each time.

I have nearly gone through a can of brake clean testing for vacuum leaks and nothing found.

Any advice greatly appreciated.

 

[mtncat1]

idle should come down when you spray it down ,i like to use ether , or water , i would spray around the crank seal ,also disconnect the throttle cable and make sure the throttle blades are closing

 

[PNW Rook]

Yeah I was thinking about trying something other than brake clean. I've used nearly a full can by now. Crank seals, manifolds etc. The spark plug color doesn't say it's pulling in air running lean though..

 

[retiredpop]

It might be worth while checking the synchronization of the throttle plates if you haven't already done so.

 

[vipermanf250]

Had that same motor did the same thing right before it blew up .Tthey have weak piston skirts that break off and take out the motor .I dont know why but the problem seems to be related

 

[PNW Rook]

Had that same motor did the same thing right before it blew up .Tthey have weak piston skirts that break off and take out the motor .I dont know why but the problem seems to be related

Now that's the kind of crap I don't want to hear!!!!
I haven't heard the skirts being a concern with the 700cc dragons. The 800 for sure though.

 

[PNW Rook]

So I went ahead and synchronized the butterflies. I'll tell ya I put my phone down there and took a pix to compare the two....I really was like this is not necessary. Did it anyways. I also obviously reset my TPS idle back to .95mvdc. When I found it, it was at .947mvdc even though I just set it last week. Started the engine and found my idle reduced to 2300rpm (YES YES YES) however I'm getting a single blink now on the info screen. I back probed the aqua wire, sensing wire, while running and I was finding 16vdc. 16VDC!!! What the heck.
So that obviously qualifies for voltage over 4.39vdc. Caused by poor connections or faulty tps. Now to do my tps testing I had back probed these connectors and front probed the unplugged ecu plug. Possibly messed up the bite of the connection for the ground? Idk whatcha think. I have never had this "1" blink code till today

I don't want to just change parts out. TPS costs $220 on Amazon, Holy cow, already bypassed not buying the exhaust temp sensor through trouble shooting.

 

[retiredpop]

Possibly messed up the bite of the connection for the ground?

You may have pushed a pin back.

 

[PNW Rook]

Possibly messed up the bite of the connection for the ground?

You may have pushed a pin back.

Yes that's what I'm thinking. Gonna release the wire and term from the connector and test fit most likely readjust.

 

[PNW Rook]

Well I hate to do it but I finally listened to others and bought some starting fluid. The clutch side crank seal appears to be bad. Hosed it down and my idle went from 3200 down to nearly killing it as I held it there. $850 just in labor, I really want to do it.i just don't have the facility to do so.

 

[retiredpop]

Good thing you finally found it, it could have been a lot more expensive if you ran it like that. As you found out brake cleaner is not a substitute for starting fluid. I think I read somewhere that some brake cleaners are not flammable while others are.

 

[PNW Rook]

So let me ask you a question.... theirs a vacuum leak "I believe", when adding more fuel to it, starting fluid, would you' expect the idle to go up or would you expect the idle to go down?

 

[retiredpop]

The idle will go down because you are introducing more "fuel" into the crankcase which causes a rich condition.