2005 Ultra 88 EFI backfiring popping
2005 Ultra 88 EFI backfiring popping
Rode bike to bar. After an hour or so, started bike & left & within one minute engine starting popping, sputtering, & backfiring thru throttle body. Barely made it home.
Things done so far.
1. Drained all gasoline & refilled fuel tank completely. Still running like crap.
2. Replaced spark plugs & gapped to 0.040
3. Confirmed good stator AC voltage output & well over 13VDC charging
4. Even tried a good battery from another bike just to rule out possibility
5. Replaced positive & negative battery cables. Cleaned chassis ground & replaced 10ga wire from battery to frame.
6. Replaced engine temp sensor on backside of front cylinder
7. Replaced Crank Position sensor
Plugs are getting black & sooty looking but havent fouled. If I take leak, wouldnt plugs be much more whiter?
What next? I may spray carb cleaner all around intake to check for leaks but seeming how issue happened so quick, I tend not to think intake leak.
OH, havent got a single engine DTC. Ive checked several times using trip reset button method. No codes.
HELP, please. Thanks
Things done so far.
1. Drained all gasoline & refilled fuel tank completely. Still running like crap.
2. Replaced spark plugs & gapped to 0.040
3. Confirmed good stator AC voltage output & well over 13VDC charging
4. Even tried a good battery from another bike just to rule out possibility
5. Replaced positive & negative battery cables. Cleaned chassis ground & replaced 10ga wire from battery to frame.
6. Replaced engine temp sensor on backside of front cylinder
7. Replaced Crank Position sensor
Plugs are getting black & sooty looking but havent fouled. If I take leak, wouldnt plugs be much more whiter?
What next? I may spray carb cleaner all around intake to check for leaks but seeming how issue happened so quick, I tend not to think intake leak.
OH, havent got a single engine DTC. Ive checked several times using trip reset button method. No codes.
HELP, please. Thanks
Put away the parts shotgun and diagnose it. At the very least do a fuel pressure test and a compression test. Check for breaks at the injector wires.
Last edited by Ed Ramberger; Apr 19, 2019 at 07:48 PM.
Whats the best way to check fuel pressure without having to use special test tooling?
Was thinking about connecting pressure gauge to nipple out bottom of tank. Isnt there a quick disconnect type fitting there?
Was thinking about connecting pressure gauge to nipple out bottom of tank. Isnt there a quick disconnect type fitting there?
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No one has worked on bike in a long time. This issue started suddenly. I’ve got the air cleaner & backplate removed. The wiring to injectors, intake air temp sensor, map sensor, & idle/air control valve look good. I was thinking about removing the IAC valve & cleaning/inspecting. Something about a possible needle sticking.
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UPDATE: Ran engine, mostly at idle at first, and sprayed almost an entire can of carb cleaner all around intake, throttle body, MAP sensor, injectors,.... everywhere & motor actually started running better for nearly half a minute or more, even with throttle & let it idle till eventually started popping back thru throttle body again. I’ve now got throttle body & intake removed. No obvious leaks noted but I’m replacing intake seals. I’m also suspicious of IAC valve. I’ll clean it & check it’s operation when I get engine running again. I’ll use petroleum grease on seals & o-rings & injectors.