|10-25-2012, 12:08 PM||#1|
Joined: Apr 2011
990 stumbling after major maintenance - troubleshooting w/ TuneECU
2007 990 Adventure here...So I'm just reassembling the bike after a major maintenance (valves, plugs, fuel filters, wp shaft/bearings, heat insulation on tanks and airbox, dual fan kit, ceramic coated head pipes,etc). This is the first time I've done the maintenance myself (13k miles now - had it done by a reputable shop at 9K miles but didn't think they did a good enough job).
I just put the left tank on last weekend and fired it up briefly to bleed the coolant and do some checks. The TPS was reading about 0.61V warm, so I dialed that down to 0.58V warm and sync'd the TBs using TuneECU so that the hPa readings match at idle
I reset the ECU but didn't let it idle for a full 15 min yet. On the center stand with engine running and small throttle openings the bike RPM is surging a bit. Checking with tuneecu running and with small throttle openings I see the map pressure reading dip on the back cylinder as the bike starts to stumble. The rear cylinder seems to have a lower pressure reading in general except at idle where I set it to match the front via the screw on the throttle linkage.
Now a couple of other random notes, when I did the valve shims I noticed some heavy varnish/dirt/gunk buildup in the intake manifold. It took a lot of elbow grease but I cleaned it out of the intake. However, unavoidably some of that varnish washed down into the engine with the tb cleaner, etc.
I also had the header pipes ceramic coated.
I have been getting a faint smoke/vapor from the exhaust if I rev it a bit. Also the exhaust smells a little weird. So I don't know if this is due to the ceramic coating, the varnish burning off, or something else entirely, but is something I'm keeping an eye on.
So I haven't done much other than to fire the bike up and see how it's going. I'm wondering if there are other checks folks would recommend that I could do with TuneECU/other to check things before taking the bike out and running it? I'm a little nervous with all the work I did to it, but it starts right up. It's never run smoothly per se but shouldn't be surging and stumbling so I'm wondering if there are any ways to diagnose that. Or is it possible it'll
(I've got open leo vince w/ akra map on there right now ie O2s are off, but may switch back to stock map and spark arrestors shortly)
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