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Bad Cold Start Problems


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Hi everyone,


Ok this was encouraged by Roger 04 RT


A) Symptoms


1) Cold rough start

2) Smokey and Major fuel smell when cold starting

3) Would not idle without using throttle until warmed up.

4) Would not ramp up to high idle on cold start.

5) Sometimes on hot start would run rough and smoke and smell

like fuel.

6) Always on cold start ( Items A 1-4 )for about 30 seconds into

warm up, then smooth out and then it would advance to high

idle position at 2k rpms.


(B) What I chased as being the problem


1) O2 sensor readings on cold start

2) Looked for corrosion on wire connections

3) Syncd Throttle Bodies many times and adjusted the BBS's and

set valve lash as many

4) Removed canister to eliminate it on cold start

5) Monitored Motronics for failure codes

6) Checked for leaky injectors after overnight sit.

7) Disconnected fuel injectors and tried to start after sitting


8) Checked adjustment of Throttle Position Sensor the Roger



© Explanation of why those items were checked.


Item B-1 Thought maybe O2 was sending a bad signal/no signal to

the Motronics. Roger O4 RT assisted me with looking at my numbers- It checked out good, was not the problem


Side Note: With strong smell of Fuel I suspected the Motronics was being told to give too much fuel on start.


Item B-2 Thought there was corrosion on connectors. No luck everything was good no corrosion found.


Item B-3 Sync'd Throttle Bodies many times- no help


Item B-4 Removed Canister, thought maybe it was full of fuel and was introducing to much fuel on start up- No help


Item B-5 Was hoping for a code from the motronics as to what might be causing the bad starts.- Never found any codes.


Item B-6 Looked for Accessive fuel after sitting over night. Never found any.


Item B-7 Thought if fuel was pooling in the Throttle Bodies it would try to fire up and then die. It never showed any hint of light off.- So no pooled fuel- No help.


Item B-8 So since I had never checked the throttle position sensor setting, I was now pulling at straws. I checked it with Roger's procedure, and found it had been done the zero=zero method (wrong) Alright I found the problem, I reset it and Boo Hoo it did not fix the problem, no help. This setting however gave me a new symptom (was the new set up related? Don't know.) However it was a subtle miss at idle that showed up after the TPS adjustment and was heard all through the rpm range that was not there before. Coincidence maybe. The miss was not audible before I made the change to the TPS.


After the TPS adjustment, I made a timing adjustment using the roadside method. WOW got 5 good starts the timing fixed it. Although you can move the timing between the slots on the plate and not yield much change though. On the 6th start it failed and went back to the smokey start and audible missing and rough running.


Conclusion: Intermittent HES. Replaced HES and now bike starts flawless and runs better than ever. I now have an R1100R that runs the way it is supposed to. This problem had been going on for over a year. I am not a seasonal rider, I ride year around. Another note: my mirrors have always been buzzy on the freeway and I just thought that that is how it must be. Not true though. After fixing this problem I can now make out what brand of car is behind me. They do not buzz anymore and are quite steady.

I did not have all the usual problems that would normally come with a failing HES.


I would like to thank Roger for the help he gave me and suggestions for things to check.

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Hello, SAS - thanks for the update.


When you replaced the HES, did you inspect the wires on the old one?


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