I have a 2001 Road King Classic EFI with stage one upgrade and 51,000 miles, always garaged. I have owned this bike for 5 years and 32000 miles. I am having an idle / stalling issue. Previous owner had no idle/stalling issues.


Two weeks ago, started bike, rode two blocks to neighbors, no issues. 30 minutes later, started bike for 50 mile ride. Started, no issues, all normal. 10 miles later while pulling into gas station, eased off throttle, bike stalls/dies. No warning lights. Coast 75 feet to pump. Fill up (93 Octane, w/ usual 4 oz. of octane boost). Won’t start. After 6 immediate attempts, I wait 20 minutes. Starts up. Head back home. Every time I ease off throttle for turn or slow down, bike stalls/dies. No warning lights. Drop to lower gear, pop clutch, it restarts. Eventually too slow of turn and bike stalls again. Wait 20 minutes won’t restart. Towed home. 45 minutes later at home, restarts. A week passes before I could get to it again. One week later, starts fine, warms up (8-9 minutes) stalls out, won’t restart. Wait 20 minutes. Restarts fine, stalls out in shorter amount of time (3-4 minutes). Repeated this about 4 times over next two days. Symptoms consistent. Never backfires. No check engine light or any other warning lights.


Yesterday. Removed air filter. Some oil on bottom of filter frame, in/around plate cover area, and on both sides of the plates. Put a new air filter on (air filter was replaced last summer, so it was not old/dirty, but replaced anyway.) Carb cleaner in throttle plate area, around/in oil evap hose, and around the IAC (Idle Air Control). A tiny bit of black gunk, and enough oil/dirt that used one shop paper towel. Start bike, warms for 10-12 minutes. Rev and release throttle, no issues. Ride to end of street, stalls while shifting from 2nd to 3rd. No restart. Push back. Wait 20 minutes. No restart. Wait another 20 minutes. Restarts. Stalls after 3-4minutes. Wait an hour. Restart and wiggle wire harness connector into IAC, no issues idles okay, but stalls as before after 5-6 minutes. Would not start today after 4-5 tries.


Anyone got a good attack plan? Thanks!

 

First off I will say NEVER spray carb cleaner into a throttle body, your air intake sensor will not work long with cleaners like that.
Stalling while coming to a stop could be the Speed Sensor, remove it from the trany, clean any metal shavings of it and reinstall it. If it still stalls you might want to replace it or have a SWEEP TEST done at the dealer to see if the speedo and speed sensor is working correctly. If the speed sensor doesn't report to the ecm that the bike is moving the ECM will shut your fuel and spark down.
The TTSM could be going bad, I believe the bank angle sensor is in the TTSM and if it is going bad the bike will stall and not start up again till it resets it;s self.
Remove and clean the CRANK POSITION SENSOR from any metal sticking to it.
There is a few things to check to get you rollin.
Doc

 

There could be many causes. Just out of curiosity, did you listen to the tank for fuel spraying against the wall from a line. I have seen a lot of these where they run for a few minutes with a line leak until the warm up fuel goes away. Another way to tell is if you add fuel and it seems to run better.

There are many basic checks on the MM EFI but your symptom of stalling after a few minutes has been observed more than once by my eyes with an internal tank leak.

Do you have the ability to perform a fuel pressure test? Just a good test to do. It should hold pressure at about 48 psi after key off on that system.

 

Check for any trouble codes.

Start the bike, and wiggle the wires going to the front injector. Sometimes they will develop an open, and it is tough to diagnose.

Inspect the fuel line inside the tank going to the pump. They will develop holes over time.

 

If you open the tank to check the fuel lines, be sure to have a new cork gasket on hand. It will dry to a pretzel in 15 min and you'll never get it back on. FWIW I just swapped my MM EFI for a Mikuni.

 

Resolved! Thank you all for your help. Doc, you were right on. CPS or speed sensor was where I was leaning also. Dealer tech got problem to repeat and put coder on it. The Crankcase Position Sensor was bad. Have taken many less than 20 mile rides, no issues, and two 70 mile short trips, no issues. Will run a short 400 mile round trip this weekend with confidence. Was told by techs that the CPS, speed sensor and a few other the IAC sensors are usual culprits. MM efi's are harder and harder to find techs with experience dealing with them. Thanks again everyone for your help.