Honda VTX 1300 / VTX 1800 Motorcycles Forum banner

1 - 7 of 7 Posts

·
Registered
2002 VTX1800C
Joined
·
15 Posts
Discussion Starter #1
So after a couple years, I finally got around to putting some serious love and attention into my bike.. I bought it right after my first daughter was born, and have had another daughter since, bought a house, got a dog.. You know, the American Dream brought to you by Visa. Needless to say, time has been a little bit of a commodity, but here’s my list of accomplishments of recent:
Completed the ground fix
Soldered the TPS wire where it connects to the PCIII, getting a consistent reading there now.
Removed pair valves and whatever all that other stuff was
Checked FPR - I think it’s still working correctly - no fuel at vacuum line
Zeroed PCIII map
Unrelated but - got a full fairing, hard bags, boards and slapped on some white walls coupled with V&H straight shots with no baffles. She’s a bad mamby jamby

Why do all this you ask? My bike has been plagued by a “running rich” ailment from day one. Fuel mileage is terrible, maybe 30 mpg on a good day. There’s a slight puff of black smoke whenever you really romp on the throttle, the pipes are black and sooty, plugs are wet and gunked up, and most scary - the oil has a slight smell of gasoline to it by time its necessary to change it. I’ll even change it early if it smells bad. I’m looking for input on anything else I should check for. After I finish my oil change, I’ll see if anything changes, if not, I’ll pull the PCIII completely. Maybe it gave up the ghost, I’d hate for it to take the rest of the bike with it. I’ve checked voltages, double checked grounds, checked connections, houses,vacuums, seals.. I’m running out of options here, looking for a handout
 

·
Registered
Joined
·
8,096 Posts
FPR = fuel pressure regulator... it's poor design.. reason Honda redesigned the fuel system. 2004

just because there is NO fuel in the lines.. does not mean it's still Good..
it's a $40.00 part.. and known to have several types of issues..

replace it.. then ride it.

PCIII.. disconnect it.. its' more trouble then its worth,,, my opinion.
unless you have internal modifications.. the Honda computer can adjust for it.
 

·
Registered
2002 VTX1800C
Joined
·
15 Posts
Discussion Starter #4
Roger that... I’ve yet to figure out the simplest way of removing the PCIII. Can I just unplug the TPS wire? I added a spade connection after soldering in the gray wire to a pig tail on the TPS so that should be simple enough. I’d rather not remove the PCIII completely, just disable it if I need to. Could I use the PCIII to compensate for a bad FPR by using negative values in my fuel map as opposed to a zero map? I’ll replace the FPR, I’m just thinking of trying that in the meantime. Eventually I’m going to add an aftermarket intake and coupled with the open pipes, wouldn’t a properly tuned PCIII give me better performance? Maybe I’m asking too much, I want the best of both worlds - better mpg and more power.
 

·
Registered
Joined
·
8,096 Posts

·
Super Moderator
Joined
·
9,739 Posts
Properly adjusted fuel controllers are well known to provide a boost in HP & torque while also often providing better fuel mileage. Of course, to properly adjust them requires a dynotune or some "home-brew" option that is similar. It is very hard to adjust them by yourself using just a seat-of-the-pants dynotune.
 

·
Mean ol' Mo' Fo'
Joined
·
341 Posts
Find a TFI somehow and forget the PC3. Then adjust the TFI to add fuel to fatten up the high end. That where you'll need added fuel. The low end is bone stock lean.
Dynotuner will help dial it in best but, you can get by thru trial and error by taking note of color of the spark plugs.
 
1 - 7 of 7 Posts
Top