09-24-2012, 11:20 AM #1
Slight surge at WOT , could it be too rich or compression causing it to pull timing?
My gprxp ski has 8650 riva ECU , xcharger, 9.5 pistons 60lb bosch injectors and powercommander to adjust fuel.
I've got 0 values in all 100% throttle settings so effectively the cmd shouldnt be doing anything.
When doing top speed runs holding wot, feel a very slight surge. Seems to max out approx 8400 rpm 91mph . The rpm gauge seems to be fairly steady, boost steady and the afrs fluctuating between 11.4 and 11.7
Could the surge be because too rich afrs or perhaps even though running premium 91 octane gas its sensing a knock and retarding ?
If normal, I wont sweat it, just want to make sure not an issues that needs to be addressed. The ski runs great all around other than that.
Idle afrs 13.2-13.5
60mph cruise 13.5
70mph cruise 13.0
09-24-2012, 11:27 AM #2
If it feels "jerky" like on, off, and back on power real quick its pulling timing. 11.4~11.7 isnt rich...11.5 is perfect IMO
09-24-2012, 11:30 AM #3
mine does that at wot too sometimes. stock ecu. not sure why it would be pulling timing unless i'm on the limiter...
09-24-2012, 11:35 AM #4
Feels more like its accelerating, then maintains, acceleration , maintains, acceleration...
It does feel like how I'd imagine it would if taking timing away or even a lean surge though the afrs dont show it.
09-24-2012, 11:37 AM #5
Is the dash tach pretty accurate on seadoos? Thats all im using for reference ? I guess I can pull a 60 sec history with candoo and see what the ecu was seeing?
09-24-2012, 11:46 AM #6
09-24-2012, 02:06 PM #7
Riva recommends 93 octane min for there ECU and with the 9.5's you may be knocking. Put your scope to use and have a peek at the piston edges.
09-24-2012, 05:57 PM #8
09-24-2012, 06:37 PM #9
Plugs and pistons look good. Doesnt seem to be any apparent issues there.
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