Hello i have a 2002 787 rfi that is driving me crazy when I got it, it wouldn't run at all in the water, but it would run on the trailer things that I have tried are: I replaced the rotary valve and sent the rotary valve cover to SBT to have it resurfaced because it was way out of spec that's when it would finally run and start in the water, but it runs poorly I have replace the fuel pump. I have verified that there is plenty of spark at the spark plugs. I have replaced the spark plugs. I have replaced the throttle position sensor. I have verified that the fuel injectors are working. And it has 145psi in each cylinder I'm fixing this for a very good friend and I'm at my wits end. I don't know what to try next. If anyone has any ideas or a checklist of things to check, I would very much appreciate it. Thank you so much in advance.
2002 gtx 787 rfi wont rev up in water
- Thread starter Joe8550
- Start date
2strokeboy
Active Member
check fuel pressure. also does it run out of water?
2strokeboy
Active Member
Im not super familiar on the 787 but it prolly could
2strokeboy
Active Member
It should be 56-58. Im not sure how much 2 psi will effect it. Not very good with the rfi and di im sure someone else can help. The rotary could be unaligned. Also check compression.
Noahsfixingbrokedownskis
Member
Check the battery voltage while you rev the engine out of the water if the battery voltage goes up above 14 volts then you need to replace the regulator. My 1996 GSX 787 had a similar problem it wouldn't rev in the water at all but would Rev on the trailer. When I checked the voltage it was spiking to almost 16 volts when revving the computer is trying to protect the mpem and will limit the RPMs if the regulator is not functioning correctly. It's an inexpensive part and once replaced solved my problem
I made a video on timing the rotary valve on the 787 RFI a while back. Here is the link. Rotary Valve Timing 787
Sounds like you've done a lot of checks so you need to rule out Valve timing as a possible cause. Don't let it get you to frustrated. Be methodical, one thing at a time. Did you remove the fuel canister and replace the filters? You could have an MPEM issue but rule out everything else first.
Sounds like you've done a lot of checks so you need to rule out Valve timing as a possible cause. Don't let it get you to frustrated. Be methodical, one thing at a time. Did you remove the fuel canister and replace the filters? You could have an MPEM issue but rule out everything else first.
