Surging
I was riding with a buddy one time and we were in the mountains. I had a Honda Goldwing and I blew on down the road way ahead. When we met up again at the end of that road my buddy was glowing and saying "Man, did you see that beautiful valley?" I didn't see squat but pavement and stripes. That day I decided to slow down and enjoy the ride rather than being addicted to destination. That was 1992.
The Harley kinda makes the journey one mile at a time. Kick back and enjoy the ride. So now, I'm the guy out on the interstate crusing along at around the speed limit with the metric bikes blowing by me.
Cleaned throttle body and holes in chamber with carb cleaner, wiped it clean and dried it out.
Started bike , watched stepper motor, out when key on , and back in when warmed up, took bike for a ride and once completely warmed up, the surging at idle started again.
Checked stepper motor at this time and it was still in, and not moving at all.
Removed and replaced ECM fuse as well, and rechecked, same thing no different.
Anyone have any other thoughts, I do appreciate the help.
Thanks.
EDIT- I only cleaned in front of the butterflys and the 2 holes in front of them, as well as the butterflys themselves.
I did not stick the straw in behind and spray, was I supposed to?
Last edited by johnod; Jun 18, 2014 at 03:53 PM.
Still stay basic and don't overlook non EFI items, spray the intake seals to head area and check for a leak. Take the connector body off the TPS and make sure no corrosion or loose pins, pull the connector off the ECM and check for corrosion on the pins. If that is ok then you will need to check the TPS with a VOM to see what is going on with it at idle, off hand I can't remember where idle volts should be but if it doesn't match the idle volts it can do some weird stuff.
When it is on fast idle at start up does it surge? or starts when it falls back to idle, that might indicate a TPS sensor is out of range.
You may have the idle set too low causing this also, should be at 1000 rpm and might be falling below desired idle and trying to catch back up or another indicator that the TPS is messing up. bump the idle up some and see if it calms down.
When I first start it on fast idle , it does not surge, when it drops off fast idle it still does not surge.
It only starts to surge after it gets completely warmed up, say after a couple of miles for instance.
I'll check all the items I can on your list of things to check.
The bike sat for about 1.5 years with just occasional starts, and no mileage.
Prior to that the ETS had been replaced not long before the storage started.
Thought I'd add that info.
What's VOM?
Thanks.
The Best of Harley-Davidson for Lifelong Riders
Now to check to see if you have any stored fault codes do this:
1. turn ignition switch on, then off, then on, off, then on and leave on. Do this fairly quickly. Pay no attention to what the fuel pump is doing.
2. Watch the red IGN light. It's going to give you a bunch of rapid blinks, pause for a second, then more rapid blinks followed by a long pause.
3. Now the blinks come slowly. Count the blinks and remember that number. There is a pause, then more blinks. Count those as well.
So after counting you should have a two digit number. That is the fault code number that the ECM has stored. After the blinking stops there will be another pause followed by either more slow blinks, or a bunch of rapid ones. The sequence will repeat from start to finish as long as you have the ign. switch on. You could have one or more fault codes. I've only ever had one at a time.
The fault code for a bad engine temperature sensor is 14. You get a 14, you got a bad ETS. They are easy to replace and despite what the service manual says, the tank and coil do NOT have to be removed to do the job.
Let us know if you have a code. Also, if you don't have a service manual, the the HARLEY one and also the parts book. Worth their weight in gold.
Carl
Now to check to see if you have any stored fault codes do this:
1. turn ignition switch on, then off, then on, off, then on and leave on. Do this fairly quickly. Pay no attention to what the fuel pump is doing.
2. Watch the red IGN light. It's going to give you a bunch of rapid blinks, pause for a second, then more rapid blinks followed by a long pause.
3. Now the blinks come slowly. Count the blinks and remember that number. There is a pause, then more blinks. Count those as well.
So after counting you should have a two digit number. That is the fault code number that the ECM has stored. After the blinking stops there will be another pause followed by either more slow blinks, or a bunch of rapid ones. The sequence will repeat from start to finish as long as you have the ign. switch on. You could have one or more fault codes. I've only ever had one at a time.
The fault code for a bad engine temperature sensor is 14. You get a 14, you got a bad ETS. They are easy to replace and despite what the service manual says, the tank and coil do NOT have to be removed to do the job.
Let us know if you have a code. Also, if you don't have a service manual, the the HARLEY one and also the parts book. Worth their weight in gold.
Carl
One thing here stands out for me and demands a question on my part.
Are you saying with the engine warm, fully at operating temp. rpm should be about 1500?
I thought it was supposed to be about 1000.
Can you clarify that for me please.
I have the Clymer manual ,and the HD manual I should have tomorrow.
I will check the codes as you suggested.
Today I turned the fast idle screw in to see what would happen, at about 1300rpm the surge disappears, but anything lower and it's right back.
This is at operating temp.
1300 seemed high to me, let me know please.
Again thanks for the help.
O the bike has a tach already.
j
Last edited by johnod; Jun 19, 2014 at 02:29 PM.









