ISCV (stepper motor) replacement

[RickV]

Has anyone ever had one go bad or replaced one?  This is the little thingy that controls the idle speed.  It's connected to the throddle bodys with vaccum hoses and has a connection that goes to the ignition modual.  Anyway... I continue to have idle problems (too low) on my `99 Tiger.  I've sync'd the TB's, checked for vaccum leaks (wouldn't that cause the idle to go up?).  Not sure what else to do, but change out the ISCV.  I've spoken to a couple of local Triumph dealers, & neitherrecall ever having to replace one of these.  I don't really want to change it out ($110) if I'm not sure that will solve the problem.  

Other than a K&N air filter, the bike is stock (with stock map).  It just turned 50K miles and runs great, just doesn't want to idle fast enough to keep the engine from stalling.  This is very anoying and can be dangerous if it stalls out at the wrong time (busy intersection, etc.).

Any help or suggestions is greatly appreciated.

RickV

[fano]

When did you check the valves last time? That was my problem.

[RickV]

The previous owner checked them about 10K ago.  Don't recall if any adjustments we required.  This issue developed about 5-6K ago, after I serviced the K&N air filter.  There's a thread in the Girly forum I started a few months back.  I took it to the Triumph dealer & they remapped it back to stock.  That got the idle rpm up to about 800, but it continues to drop down very low after the engine is up to operating temps.  It seems to vary a little from day to day, so based on that, I don't think it's related to valves.  

I think there's a vaccum sensor in the air box.  I might just change that out.  

Were your valves too loose (to cause a drop in idle?  Any other symptoms from your valves?

[fano]

They were too tight. Later on I couldn't even start it.

[JetdocX]

The dealer has a machine that can likley find your problem faster than blindly throwing parts at it.  Unless your dealer sucks, then it sucks to be you right now. :?

[Dr. Mordo]

Yeah, I have a feeling that the problem is some sensor that is clogged or coated so that it no longer works.  I would take it to the dealer.

[RickV]

Yup... you guys are right.  Need to bite the bullet & take it into a dealer.  It's just that I like fixin' things myself  (& I'm pretty cheap).  

Funny thing you two mention a clogged sensor.  There is the one sensor (barametric pressure thingy) on the back right side of the air filter housing.  This problem seemed to surface right after I "serviced" that K&N filter a couple months back.  I bet I put the filter element back in before dried out sufficiently after spraying it with filter oil.  It's down stream of the filter, next to #3 throddle body.  I'll try to clean that sensor.  If that doesn't do it... in to the Triumph shop it goes.

Thanks,
RV

[JetdocX]

Yup... you guys are right.  Need to bite the bullet & take it into a dealer.  It's just that I like fixin' things myself  (& I'm pretty cheap).  

Funny thing you two mention a clogged sensor.  There is the one sensor (barametric pressure thingy) on the back right side of the air filter housing.  This problem seemed to surface right after I "serviced" that K&N filter a couple months back.  I bet I put the filter element back in before dried out sufficiently after spraying it with filter oil.  It's down stream of the filter, next to #3 throddle body.  I'll try to clean that sensor.  If that doesn't do it... in to the Triumph shop it goes.

Thanks,
RV

Good call.  I hope that's your problem.

[Dr. Mordo]

Good luck, and let us know if that fixes it.

Something else just occurred to me.  A vacuum leak will often cause what is happening to you.  Since you were just messing with the airbox, do a very careful inspection and make sure the system is properly sealed up and that all vacuum line are connected of capped off.

[katoomon]

Other than a K&N air filter, the bike is stock (with stock map).  It just turned 50K miles and runs great, just doesn't want to idle fast enough to keep the engine from stalling.  This is very anoying and can be dangerous if it stalls out at the wrong time (busy intersection, etc.).

Any help or suggestions is greatly appreciated.

RickV

Is there any chance you over-oiled the K&N, and there is not enough air flow at low RPM?  If you still have the stock filter, you could drop it in and (2 hours later) see if there is any difference in idle.

[RickV]

I changed the vaccum sensor and that made an immediate improvement.  Still not idling at 1K... more like 800, but I can live with that.  At least it doesn't die out at stop signs.  Maybe it'll improve after riding a couple times, as the ECM reprograms to the new sensor???  I will check the intake box for proper sealing the next time I pop the tank off.  I did change the gasket for the filter holder, but I noticed the top is a little arched.  Don't know if they are made that way or the thing got warped at one time.  That could be causing a big leak around the filter.

Thanks for everyone's help!

RV