Sputtering 787 RFI

[oldbugger]

I have a 2001 GTX RFI and it is sputtering between 4000 - 4200 rpm. I just rebuilt the rave valves in an attempt to fix this problem. I can move the sputtering range by adjusting the valves, screw them in the range moves up

Any one have any ideas?

 

[El Toro 33809]

I don't think the RAVES would cause a sputtering like that, it would be more of an RPM/top speed issue. Sounds like a fuel delivery issue. Someone who knows the RFI's will probably comment.

 

[skewba98z28]

I dealt with the same issue on my old RFI. My old RFI had 3 motors in it while I had it, 3 rectifiers, tps verified good, injectors cleaned and flow tested on a flow bench good enough for nmra drag racers, fuel pressure checked on the water under load, rave solenoid checked good, rave solenoid supply voltage checked, and the check valve along with the lines replaced that supplies pressure from the crank case to the rave solenoid. Shew..... Guess what my buddy owns it now and it still does it. Oh I forgot to mention it has a new impeller, wear ring, and seal also. Needless to say we have just dealt with it. I know what your talking about. It's not the normal 787 rave opening stumble. My 96 xp and my buddies 97 gtx don't do the sputter like the RFI.

Oh and guess what that ski has a vinyl decal on the back that says "Erratic Behavior" LOL!!!

 

[oldbugger]

I dealt with the same issue on my old RFI. My old RFI had 3 motors in it while I had it, 3 rectifiers, tps verified good, injectors cleaned and flow tested on a flow bench good enough for nmra drag racers, fuel pressure checked on the water under load, rave solenoid checked good, rave solenoid supply voltage checked, and the check valve along with the lines replaced that supplies pressure from the crank case to the rave solenoid. Shew..... Guess what my buddy owns it now and it still does it. Oh I forgot to mention it has a new impeller, wear ring, and seal also. Needless to say we have just dealt with it. I know what your talking about. It's not the normal 787 rave opening stumble. My 96 xp and my buddies 97 gtx don't do the sputter like the RFI.

Oh and guess what that ski has a vinyl decal on the back that says "Erratic Behavior" LOL!!!

Thanks...I think you mentioned everything on my list... what sort of checks did you perform on the check valve and the solenoid?

 

[skewba98z28]

On the check valve I just replaced it and I made sure you could only blow through it one way. The solenoid I just hooked it to a battery and made sure when I blew through the valve with the battery hooked up it diverted air to the raves. Now with that said my buddy rode it yesterday and I brought up the sputter issue he said "oh dude it's fixed" I was like really? The stock check valve is a 1.5psi. He changed it out to a .5psi and competly replumbed the rave pressure lines again and cleaned the solenoid again. He said it still does it on occasion, but it's all good. That's why we named it Erattic Behavior haha

 

[lamajama]

I dealt with the same issue on my old RFI. My old RFI had 3 motors in it while I had it, 3 rectifiers, tps verified good, injectors cleaned and flow tested on a flow bench good enough for nmra drag racers, fuel pressure checked on the water under load, rave solenoid checked good, rave solenoid supply voltage checked, and the check valve along with the lines replaced that supplies pressure from the crank case to the rave solenoid. Shew..... Guess what my buddy owns it now and it still does it. Oh I forgot to mention it has a new impeller, wear ring, and seal also. Needless to say we have just dealt with it. I know what your talking about. It's not the normal 787 rave opening stumble. My 96 xp and my buddies 97 gtx don't do the sputter like the RFI.

Oh and guess what that ski has a vinyl decal on the back that says "Erratic Behavior" LOL!!!

Interesting..I had posted a thread on my 02 951 DI about the (what I called) "stuttering" at the 35 MPH mark but I was looking
at it from the MPH side not the RPM per se. In my case the RPM only dropped about 50 or so RPM but it definitely was missing
at that speed. Other than the 35 MPH mark the thing purrs like a kitten. I was getting resigned to the fact that it may be just
the "erratic behavior" issue...