free website stats program Newbie in trouble already | Harley Davidson Forums

Newbie in trouble already

PonyDarkmind

PonyDarkmind

New Member
Hi All,

New to the forum and new to Harleys. Bought a 2004 Fatboy, my first Harley and it's been a dog. Two years in and it's spent more time being repaired than on the road.

I've come across a problem I just can't seem to fix. I don't have sufficient privileges to post a thread in the EFI diagnostic section so a bit stuffed.

I know I caused the issue but am running out of knowledge on how to fix it.

Bike was running a little rough, stuttering every now and then when accelerating. Very rarely but annoying when it happened.

Went on an 800 mile road trip and developed an oil leak, then the engine management light started coming on for just a few seconds.

Replaced an oil pipe and all of the seals and the oil leak has gone.

The fault code from the engine management said it was a map sensor issue so swapped it out.

Also swapped the throttle position sensor while I was under the tank incase it was worn and there were flat spots. I set the TPS up for 0.275V with the cold start harness disconnected.

Also put new spark plugs in

So I start the bike and the idle is rough. Reset the ECU using the on off 3 times procedure.

Bike starts fine but idle is still lumpy. Kinda OK but every now and then it speeds up for about 2 seconds. On accelerating it stutters like crazy. It's 50:50 if I make it out of a junction. Have only been round the block and it was horrible.

Any ideas as to what I've done wrong? It's my only transport so I need to get back on the road soon.
 

Attachments

  • 20220430_154057.jpg
    20220430_154057.jpg
    2.4 MB · Views: 4
Do a wiggle test on sensor and injector wires to see if idle quality changes.
Use a spray bottle filled with water and mist the plug wires from coil to spark plugs and inspect the wires end to end for rub marks to ground.
 
Thanks, the IAC looks to be good. Idling although a bit lumpy seems OK. It revs OK when stationary and the TPS voltage it 0.275 at the ECU at idle. The big issue is reving under load. It stutters like crazy when pulling away or accelerating or just riding round the block. Slip the clutch and it settles down again. So far, New:
MAP sensor
TPS
plugs,
Air filter
As well as the stuff to sort the oil leak.

joel said:
Do a wiggle test on sensor and injector wires to see if idle quality changes.
Use a spray bottle filled with water and mist the plug wires from coil to spark plugs and inspect the wires end to end for rub marks to ground.
Click to expand...
I guess cos it started with a MAP sensor code I've been concentrating on that side of things. I'll give this ago tomorrow, thanks
 
Last edited by a moderator:
Could be a dirty fuel filter or a bad injector as well, do a fuel pressure test to eliminate the issue as fuel related. Have you checked all your power and ground connections?
 
Like Jeff said check for pin hole in fuel line in the tank. Hose rests against the tank and vibration will rub a hole in fuel line. Also make sure tank lining isn't peeling and clogging fuel filter.
 
You must log in or register to reply here.
Back
Top