rr ecu gone south?

[skillet]

I have an 04 rxp with rr ecu, riva I/c, stage 1, 15/20r, thru hull exhaust, pro block offs, lightened top end on fresh motor. (the super charger set at 11lbs) new wear ring, new denso's, oil level is perfect, retard on the timing but ever since I got it back I couldnt get past 8300 rpm with a 14/20r at the time, threw in the 15/20 and cant break 8150 rpm, the motor dosent seem to max rpm or be as snappy as before the rebuild. could it be the new stainless valves (I dont really believe that) or an ecu going bad? had it out this weekend and was sitting in a cove (not running) and got out past the no wake, when I jumped on it it ran for 3-4 mins when it started to sputter and then died, I fired it back up right away and it didnt want to run if you were on the gas above 2300 rpm, it acted like it was out of gas but it had half a tank. no codes came up and it wasnt hot the oil was clean and I almost think its the fuel pump going out. my buddy pulled me in and since the boat would idle I let it for the 10 mile pull behind the boat, didnt want to force water in the motor. when I got it on the trailer it reved out for about 10 sec before it sputtered and died again. any thoughts?

[johnD]

Try dropping the denso's and going back to the oem plugs. That solved my problems, I instantly got 300rpms that I lost. I have been hunting down this problem for months and kept forgetting the tip that was given to me by another member here. For some reason, the Denso's we're misfiring at high rpms, it would run good for like a second then drop down 300revs. Specially if you load the pump from a sharp fast turn.

John

[GTXX]

you say it's a fresh motor, how fresh?

[two2curupt]

How fresh and were are you located??
What is giving you 11lbs of boost as well??
RR sc impeller or one of Les Cook's kits??

[BDNJ]

Are you running any aftermarket fuel controller? What about injectors? You just can't throw in a 11 lb s/c without adjusting the fuel. I would swap your RR ecu with your stock one and see if it runs better to 8100. That could help isolate the rr a little bit more.

Brendan

[BDNJ]

How fresh and were are you located??
What is giving you 11lbs of boost as well??
RR sc impeller or one of Les Cook's kits??

Two2curupt: The rr only gives 9.6 lbs @ 8500. I don't think he could be turning 11 lbs @ 8300 with that wheel, imo.

[Green Hulk]

He means he has his clutch slip moment at 11 ft. lbs

Your cam being retarded is more than likely the problem. You only retard the cam with the stock class ECU.

[BDNJ]

Oh. Good catch Jer. My bad.

[skillet]

you say it's a fresh motor, how fresh?

approx 3 hours, and I didnt mean it had 11lbs boost, thats what the slip was set at on the sc. it had this problem before the denso's so I know it wasnt that, same with retarding the cam I did both of these things hoping it would improve my situation. I am in arizona and even though its 200 degrees here I had the chance to run in 70 degree weather here one early morning and took it to longbeach last weekend to practice for a race and got the same results, I'm going to try to run it with the stock ecu to see if I still hit 8100 rpm. the boat is not missing at all and does sound healthy, it just is way down on speed, rpm and snap. has anyone seen an rr ecu go bad? what should my stock compression be? (gonna check that today)

[BDNJ]

STOCK CAM app.140/145
RR CAM app. 120/125 or so i have heard