2000 GTX 951 DI rough idle, dies

[daschrimpf]

I picked up a 2000 GTX DI for cheap knowing it doesn't run properly. To be specific, the ski starts right up when its cold and will idle, however it idles very roughly (fluctuating rpm, sputtering). When applying throttle, the rpms climb as they should and it sounds fairly healthy. However, when the throttle is released the engine will drop in rpm and die.

The fuel pressure is a healthy 110 psi and the air/fuel rail reads 28 psi. Leak test for solenoid showed no issues however one rave valve was leaking at the seal. I ordered a replacement rave rebuild kit which will hopefully fix the leaking issue but I'm unsure if that will bring the ski back to normal altogether. I also ordered a pressure relief valve to test the pressure at the compressor outlet to see if that's normal. Additionally, plugs are a little on the wet side.

Has anyone had these issues? Can a leaky rave valve completely dog the system to the point of sputtering and dying? Next step would be to bring it to a dealership and check for any error codes.

 

[WaarrEagle]

What exactly are you measuring when you see 28 psi? You should see 27psi of fuel pressure when the pump runs at key insert but with the motor off.

 

[daschrimpf]

What exactly are you measuring when you see 28 psi? You should see 27psi of fuel pressure when the pump runs at key insert but with the motor off.

27 28 psi, same thing. Measured it just like you stated, by attaching the safety lanyard. Fuel pump is not the problem.

 

[WaarrEagle]

If your fuel pressure is steady at 107 while the engine is running/revving, then your air compressor is fine. Have you checked compression?

 

[jhjesse]

I would check compression first.
Does the ski have a maintenance light?

 

[daschrimpf]

I would check compression first.
Does the ski have a maintenance light?

No maintenance light, compression is good.

 

[jhjesse]

That’s good news. I would fix the rave valves and replace the fuel filters.
There is two filters in the fuel pump assembly and the big inline filter on the supply hose.
The internal filters can be purchased at most any auto parts store.
Airtex FS242
Airtex FS220
The inline filter can be purchased from OEM or you can do like many of us have done and cut the old one out and replace with WIX 33095 filter with two stainless steel hose clamps for a fraction of the cost.

 

[daschrimpf]

For anyone still curious. I replaced the seals in both RAVE valves and now the ski will idle and rev just fine, no dying, however the idle seemed a little frail, almost like it wanted to die and was barely holding on. Feeling confident enough to test it out, dropped it in the water yesterday and there's still something wrong with it.

Right off the bat it didn't want to idle anymore. I'm thinking the extra stress of pulling in water from the lake rather than a hose was too much for it to handle. However, when I would hit the start button and immediately give it some throttle, it opened up nice and got up to a respectable operating speed but would always die when letting off the throttle.

I could faintly smell gas and the longer I was on it, the less willing it was to climb in rpm. I was sure it was getting too much gas and after trailering it and pulling the plugs, I was right. Plugs were sooty black and fouled.

I'm thinking the problem could lie in the throttle position sensor. I think its telling the computer to give it too much gas which is killing it on idle but it does okay up in the higher rpms.

Does anyone have any thoughts? Should I go ahead and replace the TPS?