So, the bike is all back together after the winter mods! Went for a little shakedown ride a couple weekends ago, and she starts stalling. Every time I pull in the clutch, it drops to idle and then stalls right out. OK, first thing I think of is pin holes in the fuel pump lines. Pull the pump and voila! 2 holes in the line between the pump and the filter. Got the fuel filter kit from the dealer and the 2nd line with the quick disconnect as well.

Replaced everything, figured I'd be good to go right? Does the exact same thing. Get on it, pull the clutch and the RPM's just keep dropping till it dies. I can keep it alive by blipping the throttle, and while riding everything seems fine. I'll also add that it idles and revs just fine sitting in the driveway, it only happens after I put a load on it. It also restarts without hesitation and without cycling the ignition switch. Just hit the button while I'm rolling and she fires right up.

I decide to fill the tank and see if it runs any better, maybe the new lines are leaking. Full tank and the problem is slightly better. Not perfect, still stalls a couple times on a 15 mile run, but at least not every time I pull the clutch. So I figure that points to a lingering prob in the tank. Pull the fuel pump again, remove all the lines and inspect, reinstall lines and all new hose clamps etc.. Put her back together and she seems to run great on a short run. No stalls and I figure problem solved.

Yesterday I took it out for a longer run, and she starts stalling again. DAMN IT! Now I'm puzzled. I think maybe the MAF or IAC sensors are gummed up, so I get some cleaner and go to town on the throttle body. There is quite a bit of oily residue inside the AC and the backing plate is blackened pretty good, so I think this may be a possibility. I also unplugged the TPS while cleaning, and forgot to plug it back in. It starts fine, I increase the RPM's and let off and it drops to idle and stalls out. Now I realize that I have the TPS disconnected, and it's doing in the garage what it does on the road. So I start thinking it may be the TPS. Head to the dealer and order one for $36.

Meanwhile, I decide to take it out for a few rides to see if cleaning the intake made any difference. First 10 mile spin and she seems OK, can't get her to stall at all. Decide to take it for a second run, and I'm gettin on it on a side road and there's a cop sitting around the bend this time. F**K ME! He blips the lights and points at me to pull it over. Pull in the clutch to comply and it stalls out. Double F**K ME! 52 in a 30, at least I only got a warning, and he didn't seem to care about the bike and helmet not meeting a half dozen DOT regs. Continue that ride and it stalls a couple more times.

So that's where I am now, TPS is on order, I'm thinking it may have something to do with the problem, but why only under a load? Shouldn't it act up in the driveway as well? All the in-tank guts have been replaced aside from the fuel pump and pressure regulator. I just can't wrap my head around it. She ran flawlessly right before she went on the lift for winter mods, and I didn't do any motor work. Only the dash relo, which is working great BTW!

I know, long post. Just looking to get all the variables out there, maybe someone has run into this before and can shed some light on where to focus my efforts. I can no longer pull codes unless I find a scanner, the aftermarket speedo doesn't offer that function. Thanks for your time guys! Hoping the wealth of knowledge in here can point me in a direction!

 

Since you seem to have everything covered, I'm just going to try this:

The little red cap on that stub of a tube is a replacement for the balck rubber one that was pretty much rotted off mine. I discovered it during my 98" build. I also ended up replacing the rubber breather tubes as they were rotted as well. I was told these items, particularly the the one I used the red cap on will cause erratic idle.
On another note, have you checked fuel pressure?

 

Haven't checked the fuel pressure yet. Don't have one of those gauge setups, and since it only does it on the road, not sure if it'll help a whole lot. Plus I'm not sure exactly what I'm looking at as far as pressures go. If I exhaust all the simple options, I'll take it in to the Indy and see if he can diagnose, maybe pull some codes. My work schedule and his shop hours conflict, so I won't be able to get it there for a week or more. I'll check that cap, I did notice it but didn't pay it much attention. The breather tubes seem fine.

 

Curious problem. I'll be interested in what you discover.

 

My guess is the TPS, since cleaning the IAC didn't help and you can't find a delivery problem.

 

New TPS, cleaned the IAC, and same old ****. I think I'll burn it and collect the insurance........

 

Fuel pump would be next guess, I guess. Unless an something electrical is heating up and then failing, as in the coil.

 

I removed the IAC and gave it a good cleaning, and regreased the pintle shaft with some white lithium, also pulled the MAP sensor and sprayed that out with some cleaner. Still stalls.

Seems to be stalling mainly after decel. I can accelerate, pull the clutch, and she seems to drop back to idle fine. After heavy decel, I'll sometimes pull the clutch and she'll stall. I can now pretty much predict when it will stall, I'll get a few big decel pops, then when I pull the clutch to coast it'll die. If I pull the clutch before I hear the pops, it usually will not stall. Could the IAC be losing its step and closing too much on heavy decel? Then not have enough air to maintain idle? Bad MAP sensor maybe?

I read a thread about a similar issue and the solution that fixed it was the speed sensor? Might be my next step, since I did replace the speedo and rewired the sensor, maybe something there......though speedo seems to work fine, and I'm not sure why that would cause this problem....

I guess it could be the fuel pump, but doesn't seem like that would be a likely culprit since it is an intermittent issue and it fires right back up without cycling the ignition switch to repressurize the line.

 

Just read a thread regarding speed sensor issues. Seems I have another symptom that I thought was completely unrelated - my turn sigs stopped auto canceling. From what I've read, that coupled with the stalling issue points to a bad speed sensor. Headed to the dealer now to see if they have one.......

 

dont know if this helps , but, i have always been told, when i work on my ride and she doesnt run right afterwards then i need to go over everything i did to see what i did wrong...
i have found this out to be more true more times then not

hope it helps