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Ignition/Tuner/ECM/Fuel InjectionNeed advice on ignition issues? Questions about a tuner? Have questions about a EFI calibration or Fuel Injection? Tips on Engine Diagnostics, how to get codes, and what they mean. Find your answers here.
When I am riding at 3500 to 4000 RPM (no tac) or in 5th gear (75mph). the engine misses bad, that will also happen in all gears at higher rpm with the throttle steady, but when I accelerate the missing goes away until I go to a steady speed again.
I took it to Harley , check codes, map, fuel line pressure, intakes, nothing showed up.
I have changed plugs, plugs wires, I think the coil is OK, ruled out fuel, I have looked at the injector connections.
One person said that with this system it is probably the throttle position senson, how can I check this out, short of buying a new one.
Also in my manual it refers to in the trouble shooting area to a break out box, where would you get one of these.
I need help
sorry for your problems.
1-does the missing only occur at load? while moving?
2-does it miss IF bike is at rest/stopped but RPM is raised and maintained (steadied)?
3-did you get a check engine light?
4-does it happen randomly and starts spitting, coughing, missing when cold and also when hot.
5-in your hd service book. diagnostics section or fuel injection section there should be an outline of how to read codes with-out tools..any historical codes?
* a shot in the dark, consider review of engine temp. sensor..it may not give a code.
more common M and M issues reported on the forum have been:
*crank position sensor
*cam position sensor
*engine temp. sensor
*corrosion at the ECM connector..just requires clean-up of contacts..more common on bikes stored in colder climates.
*ground wire from battery to frame loose or damaged.
A faulty coil could also give the same symptom. So could a charging system problem.
The harley shop checked all of this and let you go????
Thanks for the reply, I have look at the wiring all looks good but how knows, I have checked the ground,
Engine runs fine at idle or at lower rpm, hot or cold. Engine light OK.
I am going to change out the throttle position sensor, and see, will let know.
i pressure checked them too and they were fine in the shop but under load they seemed to be starved for fuel so i was replacing the fuel filter and found the holes, also had same problems on other bikes it was crank pos sen, ecm and iac but the fuel line is an asy one to rule out
This HDForun is ausome, you all have helped me to solve my problem, as I said earlier, I change the plug wires, plugs, pressure checked fuel lines, checked for intake leaks, checked wiring and the coil but, the problem was the throttle positioning sensor, it runs like new money. Thank you all
BOBOLOBO, were you able to do this yourself or did the Harley shop do it?
I have the very same problem just started on the way to Sturgis on Wed. and all the way home If I ran at 65mph or 80mph did not notice it.
Was reading the shop manual and sounded a little confusing.
How much was the part?
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