injector problem on apex

[overkill131313]

can anyone help me with some info?

06 MCX (310) Apex with an issue......was coming down from last ride and it started to run on 3 cylinders up untill boost came on.....it is like a sticking injector or a bad connection....works great when the duty cycle is close to the 100% or the top end of the injector but runns ruff just going down the trail.....just started doing it. the MCX injectors are removed and running a pure logic fuel controler set up with the Yamaha injection system.....dont jump in and say the pure logic box is crap because the sled ran perfect up un till last ride........how can I test injectors or wiring? any in put would be great! I dont think it is plugs because if it was a bad plug it should get worst under boost....not better! HELP!

 

[06yamahaapex]

what are your settings at on your pure logic box?? do you have an air fuel gauge??

 

[overkill131313]

what are your settings at on your pure logic box?? do you have an air fuel gauge??

I have not touched the box and was told not to touch it because it is all set up! I need to get a new O2 sensor for my gauge because of the lead fuel......but it ran flawlessly so far.....then 2 km from the bottom it started missing! I dont even know how to work the fuel box but the last owner said dont touch it! lol......I went for a test ride today and about a mile up the hill it started doing it......Im back home in the garage confused what to do!

 

[06yamahaapex]

did it work ok up top just cruising with low boost??

 

[Nytroman]

buddies 2006 Apex did same thing, would run on multiple cylinders, run fine at WOT with boost. We checked wiring, fuel etc and think he ended up by passing the tors. My Nytro did similiar thing on way into Quartz, wouldn't even move off idle, had to by pass mine as well. Yours probably is by passed already

 

[06yamahaapex]

if tors is acting up sled will run but wont work fine once u get on the throttle....just stumbles on its face when tors acts up....sounds like its running rich or lean on the cruise and acceleration settings (1 and 2) on the pure logic box...then once the main jet circuit (mode 3) its in the 12-13 range for air fuel to run like it should.....

 

[overkill131313]

did it work ok up top just cruising with low boost??

it just started doing it 2 km from the bottom of the hill on the last ride.....was going to change the plugs when I started thinking it was not the plugs.......I went a mile down the beach to day and samething! dont want to take it back up the hill to see if it works up there.....I need to get a new NTK O2 sensor for my FJO wideband gauge!

 

[Nytroman]

if tors is acting up sled will run but wont work fine once u get on the throttle....just stumbles on its face when tors acts up....sounds like its running rich or lean on the cruise and acceleration settings (1 and 2) on the pure logic box...then once the main jet circuit (mode 3) its in the 12-13 range for air fuel to run like it should.....

I agree, thats why we waisted a weekend going through everthing else but that cuz the TORS "dont act like that" Eventually after the ruined weekend we swapped it and sled run great rest of season. I just would not leave one hooked up IMO

 

[overkill131313]

I agree, thats why we waisted a weekend going through everthing else but that cuz the TORS "dont act like that" Eventually after the ruined weekend we swapped it and sled run great rest of season. I just would not leave one hooked up IMO

what is TORS?

 

[06yamahaapex]

throttle over ride system

 

[overkill131313]

it does not cause the engine to die but it just sounds like it goes down to 3 cylinders then goes away after some throttle is added!

 

[NM]

I know you said it's not the PL box, but I would bet thats exactly what it is. I have had it happen many times to my Apex. It sounds like it's wet or lost it's program. Take the box off and put it on a warm htr vent overnight, then try it again. Also check all the connectors in the plug and the black ground wire. The only other thing I ca think of would be the TPS.

NM

 

[400hp]

had this problem also on alpine turbo....replace injector # 4,,,seems to collect all the junk from fuel and then this happens...try that and ket me know

 

[overkill131313]

I know you said it's not the PL box, but I would bet thats exactly what it is. I have had it happen many times to my Apex. It sounds like it's wet or lost it's program. Take the box off and put it on a warm htr vent overnight, then try it again. Also check all the connectors in the plug and the black ground wire. The only other thing I ca think of would be the TPS.

NM

box is not wet since the sled had been in the shop for 3 weeks, after yesterdays test ride. if it lost its program I think it would not run in the top end. the box looks like it never gets wet since it is under the hood 99% of the time.

 

[overkill131313]

going to have to get a new O2 sensor and see what my reading is on my gauge first.......might be off and have to change my setting on my box.....it really does sound like an injector........I like the #4 injector idea!

 

[overkill131313]

oes anyone know of a place that cleans and flow tests injectors? years ago I used to send my injectors down to the states to get them tested for my Buick Grand National but was looking for some thing closer!

 

[overkill131313]

has any one tried SEAFOAM in their 4 stroke sled? I have used it in my truck and it worked but thinking I should try it in the sled to clean the injectors........turn the boost right down put some in and go for a slow trail ride for and hour or two! does anyone sea a problem with this?

 

[Longhorn]

Ive heard of a lot of guys using it in their boats with no issue, the website claims it is safe for all engines, but I havent ever heard of anyone using it in a sled??

 

[400hp]

get into habit of just replacing injector 4 every year when you do oil change etc...also consider moving your pure logic box out from underneath your hood and onto your handle bars where you can see it...they shouldn't be under hood...to hot and moist there..

 

[overkill131313]

Ive heard of a lot of guys using it in their boats with no issue, the website claims it is safe for all engines, but I havent ever heard of anyone using it in a sled??

I have used it in everything but a sled........4 stroke is a 4 stroke so going to get some in the morning and give it a try........ it is worth a try if it is just a dirty injector lol!