2004 heritage classic efi. Spits sputters stalls and is burning through gas like crazy. Pretty well stock, just beauty mods, runs fine cold once its warm, hard to stay running and surges during cruising speeds, checked hoses, fuel lines, plugs and wires, drained/flushed tank, new fuel then added sea foam, cleared it up briefly, now back to it. Dont know what to try next. Ran great prior to putting new battery and starter relay.

 

Guess: faulty engine temp sensor. Incorrect temp input to ECU causes improper mixture. Can check resistance to verify...

 

If it's not a sensor, it may be the fuel pressure regulator housing. They are notorious for pushing off and causing a fuel pressure drop. The only way to check it is to do a fuel pressure test or pull the fuel pump and look. You can lift the pump assembly high enough to see without actually removing the assembly from the tank..

 

Interesting...... Usually, if you have a problem develop right after you work on a bike, the issue can be traced to the work you did..... But I can't think of a reason how, the work you did, would/could cause the symptoms you are having... unless there is a bad ground, or you bumped, loosened a connection during the battery/relay install...

Is the bike throwing any codes?

In addition to some of the other suggestions, if the sea foam fixed it briefly, you may have a sticking fuel injector...

Let us know the resolution.....

 

That was first thing i looked into, something i bumped or loosened, checked and rechecked grounds all wires,leads etc. Only threw one code when i changed the battery, battery high charge, no others codes since. Cleaned butterfly and idle control, breifly helped, the sea foam helped but it goes right back to it.

 

New battery
New starter relay
New ignition coil, ran great for a day or two after this.
New plugs /wires.
New fuel pump, fuel filter, fuel pressure regulator, both hoses, drained clean gas tank, fresh non ethanol fuel,
Sprayed entire engine to check for leaks,
Cleaned throttle body, cleaned every connection i could reach, checked every hose/ wire on the bike.now seems to be surging at cruising speeds, no codes other that 1sr one, battery STILL RUNS LIKE ****

 

Is it idling funny or dying at stop signs in neutral?
This thread had somewhat similar issues and the OP fixed it with a new throttle position sensor.
https://www.hdforums.com/forum/dyna-...at-idle-4.html

 

Idk but worth a shot, already threw a couple hundred at it might as well try more, heard it might be crank sensor as well, that should arrive tomorrow, stealership is lost .....✌

 

Well i guess i can add a crank position sensor to the list that its not. Thinking of trading for metric, sick and tired of this harley

 

Well i can add throttle position sensor to this bull