03-11-2015, 11:34 AM #1
HELP! 787 RFI starting / fuel issues
I have a 787 RFI that will not start. It turns over fine but will not fire. It has good compression and spark. I verified timing with a timing light and compression is about 155psi. The plugs look very wet and the engine looks flooded. If it sits for a while it will fire and run for a few seconds then slowly shut off - as if it is getting flooded by stuck injectors or something. This is happening in both cylinders.
Does anyone have any suggestions to look at? Could the TPS be off, thinking it is at a higher throttle angle, therefore causing it to inject more fuel? Is this a MPEM issue maybe?
Thanks in advance!
03-12-2015, 04:09 PM #2
Check your connections at the ignition coil and make sure they are tight, pins in connectors not pushed back or broke off. Sounds like you have a spark issue.
03-14-2015, 12:09 PM #3
Spark is good, verified with timing light. I was running it on the hose and it slowly shut off. Pulled plugs and there were very wet with fuel. I can clean plugs, re-install and the engine will fire for a brief second, the shut off - plugs dripping wet again. This is why i think it is a fueling issue. I am going to pull the injectors out today and see what they look like.
03-14-2015, 08:29 PM #4
Change the plugs. You would be amazed how many skis I've bought that " didn't run" due to old crap plugs.
03-15-2015, 03:00 AM #5
03-15-2015, 10:44 AM #6
- Join Date
- May 2008
- Elephant Butte New Mexico
I would not go to the injectors just yet...
if the rv is screwed the same mixture is compressed over and over again..seems like the engine has good compression, but it's the same charge over and over again with added fuel to help drown the engine out.
remove flame arrestor, put hand over throttle body ( remove and ground plug caps)..crank the engine, you should feel engine vacuum.
if the engine has high hours ( over 250) the valve may have failed. check the throttle plate. I've seen one of the screws come out and trash the RV.
RFis tend to be pretty reliable until the crank seals start ailing.
03-15-2015, 12:00 PM #7
I'm not saying you don't have spark, but you could still have a spark issue. Check coil connections as I said, ohm out coil if you can, try new plugs. Many times a weak spark can seem just like too much fuel.
03-19-2015, 11:31 AM #8
03-19-2015, 05:36 PM #9
Ouch! Your crank is likely bad also.
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