new to these forums things, anyhow can't get a mechanic for awhile but my issue is when i bought the bike last year from a friend of mine the engine light would come on once in awhile then go out after 8 sec it ran fine with no issues but now the engine light is staying on and running rough, at low rpm, if i run it on the highway at 60 mph the light goes out and it runs fine but as soon i goes into town at low rpm it stays running rough. missing a bit and really hesitant when i give it much throttle, the plugs are black as the exhaust. it's fuel injection and i haven't heard good things about that, any ideas would certainly be helpful
thanks boys

 

A check engine light that comes ON but later goes OFF is indicative of a historical code if bike runs fine.
A check engine light that comes ON and stays ON is a constant error.
Since the bike runs rough at low RPM then i would get a digital voltage meter and review the voltage at battery post.
At rest.
While cranking.
At high idle.
Then report back with that information.
Could be something really simple like a loose battery cable at one of the FOUR ends.

 

To me it reads like an electrical issue..loose wire, bad battery or charging system problem.
I have a 98 road king with fuel inj. and i can read codes thru check engine light with no tools..
Put handle bar switch on RUN.
does this work for you?:
1-turn ignition key switch to ignition ON and then turn OFF 1 second after pump stops.
2.repeat #1 again..remember 1 second after pump stops
3.turn ignition key switch to ignition ON again and wait about 8 seconds for a bunch of flashing of the check engine light
it will then stop for 2 seconds..get ready... these are the codes you must count:
it will slowly flash 1,2,3,5....there is NO 4....this is the first digit of the 2 digit code ..so it can only be 1,2,3,5 __ __
then a 2 second pause...then you will get second digit of the 2 digit code..it can only be 1,2,3,4,5,6
remember after the complete 2 digit code is given you will go back to the rapid flash sequence..
it will then repeat the code again or go to next code if there is one.
there are a total of 15 codes available with this procedure
examples
52,53,54,55 bad news ECM replacement
56 crank/cam sensor ---very very common, any backfire gives this one.
11 throttle sensor
12 barometric 14 engine temp. sensor 15 intake temp sensor
23 and 32 are injectors front/rear
24 coil
33 fuel pump relay--in this case you would not hear the pump but instead waited 3 seconds after the on / off sequence
Let us know what happens.

 

Common problems for that era:
1-COMMON...Two fuel hoses under tank leak after 10 years. Harley $$$$$$$, Goodridge HDFL005 under $160 USA dollars or LESS total for BOTH if you check google .
The Goodridge lines are less than half the price of the Harley parts and are of good quality.
2-COMMON..speedometer LCD (odometer screen bleed). requires replacement when unable to read miles ridden if that is important to you. Requires cutting about 12 wires. NOT PLUG AND PLAY LIKE NEWER ONES. A retrofit kit is available to make it plug and play but you still need to cut about 12 wires.
It is a different manufacturer from the newer ones.
3-COMMON..Cam position sensor...very difficult starting, lots of cranking but does not catch. A lot of cranking and no start then you wait a second and a quick tap to start button and it starts with very little cranking…look for visible goo (beige) leak under timer cone (right foot) at black wire exit from bottom of cone…You will have plenty of warning…dozens and dozens of difficult starts.
4-CRANK position sensor by oil filter (RARE) but if you use a power commander the signal must be 100%..This is very rare.
5-(MEDIUM COMMON)Tank liner releases at middle section near fuel pump..blocks flow of fuel..loss of power, slow down and piece moves from fuel inlet so bike is OK but then becomes trapped again so cycle repeats.. FREE REPAIR..open gas tank access lid, drain fuel and clean piece out..I would carry the little bit required to remove screw..The book says you need to replace the one time use screws but if you are careful and replace in the same location it will be re-usable at least one time..
6- VERY COMMON...ENGINE TEMPERATURE SENSOR...very common, general rough riding as bike bucks from cold to hot rapidly..$100 part…an emergency bypass is to disconnect the Idle speed control but then you need to hold throttle at warm-up.
7- Bikes that are pressure washed or in snow conditions with salt roads or people that added a power commander and destroyed the rubber boot at ECM..GROUNDING PIN ON ECM becomes corroded and requires cleaning.
8-The little chrome cover cap thing with the allen bolt on the starter end will get loose one time and you will chase the rattle a long time until you figure out that under the cover is two 0.15 cent nuts and one is lost.
***-The shift linkage ends SUCK on all harleys and you need to change those yesterday to heim joints look on ebay if on a budget for: Heim Joint Rod End 5/16" with bolts for Harley Davidson as they should be about $10-$15 delivered for both.
****VERY IMPORTANT...THE CAM POSITION SENSOR USES AN INSERT TWIST AND LOCK CONNECTION. MAKE 100% sure it is tight, zip tied and secure and then tie it one more time.. Located at throttle side of frame behind the PAINTED plastic side cover by seat (remove cover) and hidden by the triangle portion of frame..connector is black and about 2 or 3 inches long and the thickness of a fat pencil.
That thing had me scratching my head for a long time trying to chase an intermittant cut-off over bumps. Side of the road frustration thing..Many shops are unable to identify the simple problem while others waste your money by replacing it when it was only loose.
THE PARTS ARE READILY AVAILABLE for this bike with the exception of the gas tank from either the dealer or aftermarket.
I would imagine you have the service book or will get the service book for this bike from Harley for about $50 . Finally if needed when you get the book read the ONE EFI chapter. You can review check engine codes with no tools by following a simple sequence.
I would review the fuel lines. If you do NOT have the goodridge lines HDFL005 then I would consider carrying some in your saddle bag. Rarely does a dealer stock the Harley ones.
People give opinions all the time but the fact is very few want to read the one chapter in the service book on EFI for the M & M bikes and instead just decide to throw parts at a bike.
It is a very simple system with very few components.
Consider using regular Dyno oil as the synthetics are too good at locating leaks.

 

that's a great post..

 

Head temp sensor.

Replaced it a couple times. $100

Wayne

 

Hi (especially to IM)

I have a 97 road king that has been playing me up for months. The most recent "fix" was to replace the temperature sensor which fixed the problems I had with under/over revving, black smoke, and backfiring.

Now I have a CEL indicating 56 Cam/Crank position sensor. It is not on permanently but I suspect it is being re-generated after every run, rather than just indicating an historic fault.

But how do I know which sensor is playing up?

The symptoms are:
1. The bike will run fine for a few miles then cut out completely. After a few minutes it will start again and get me home.
2. On occasion, if I rev the engine at a standstill, it will cut out immediately. But not always.
3. Yesterday, bike would not start after being ridden and left parked for 30-45 minutes. A prod and poke at every electrical connector and wire from each sensor all the way back to the ECU, which I repeated twice, and the bike started. But I am not sure that I actually did anything during that prodding and poking!

Thinks to note: I have a Power Commander 3 fitted, but the "rev and cut out" happened when I took the PC out of the loop. I have reconnected the PC now.
I have an SS Stroker kit and high lift cam. Had this setup for about 10 years so not sure it would be relevant.

What would be your view on the issue? I have double checked the cam sensor twist and lock thing and it 'appears' to be very tight and when I put it back I wedged it so that both ends were pushing against each other. Highly scientific I know!

I'm ok with replacing a sensor but I didn't want to replace both just because I'm not sure which one is failing....

 

When it acts up pull a plug wire and crank it, if it has no spark then it is the nose cone cam sensor, if it has spark then it is the crank sensor. The crank sensor controls the injectors opening cycle, cam sensor controls the coil. Problem is that both sensors can be affected by heat but the cam sensor stands out more known to fail and melt which is visable when pulling the cover. Crank sensor can shut off after running for a while and fire back up when cooling off so pull a plug wire allowing it to jump spark to the spark plug and make sure you don't hold it when cranking if your not familiar with spark, note: dam spark can still knock the crap out of you with a rag.

From experience a crank sensor has to be in full operating range with a PC3, if it is slightly weak a PC3 doesn't read it and shuts off

 

Thanks for you very quick response! However I'm not sure what you mean by "pull a plug wire allowing it to jump spark to the spark plug"... Could you explain it in simple terms to a guy who is scared to death of the spark having been bitten more than once!

Phil

 

If it has a fuel tuner then try taking the tuner out of line, and connect the ecm directly. If it works then the tuner may be on its way out.


Check under the nosecone for tan dripping goo. If that's there then it is your cam position sensor.


Check the crank position sensor connector located behind the right side cover. It is the barrel shaped connector. Take it apart, clean it up, add a bit of dielectric grease, reconnect it, and cross zip tie it so it will not come apart.