Hi I'm running into a tough problem to solve. My 2006 night train with 11,0000 mile was running perfectly and then was parked for about 3 months. When I started it the idle was rough and it would cough through the intake. I ran the gas out and refilled yet the problem got worse. I cleaned the throttle body and then went ahead and replaced the IAC motor which had no effect on the problem. I re-flashed the map on my Thundermax with little change. I checked the plugs and they look good. Then I did some reading here and began to suspect a fuel pressure problem so I bought a MC500 fuel tool which shows exactly 60psi while running (no bouncing of needle). When I flip the run switch I hear the very light sounds like fuel swishing in the tank and see ripple in the tank. I made a video . Is it possible to have a problem inside the tank yet measure 60psi on the line? Does that video look normal?


Fuel Tool:

 

Hard to tell from the video but I suspect you have a hole in that fuel line inside the tank, or a leak at the regulator

 

I thought that too but I'm wondering if I would still have 60 psi of pressure then? It seems like my pressure is fine.

 

Ok well, I pulled the fuel pump assembly and there were no leaks in the lines or cracked housing. The swishing sound in the tank must be normal and that's why I have 60 lbs of pressure so I can eliminate that. The plugs are a typical gray color so I'm not sure what's going on at this point, there's no trouble codes. When I start it sometimes it revs up real high and I have to shut it off. When it starts somewhat normally and idles it runs terrible then stalls. I just completely drained the gas tank and will refill with new gas and I have 2 new 23 degree injectors to replace the stock 8 degree ones. I'll post the outcome with a video of it running when I'm done.

 

Ok done with repairs. Still running the same. Any ideas?

New gas
New IAC motor
New injectors
Good fuel pressure 60psi
Checked all connections
New battery
Plugs look ok (gray to dark)
Flashed a fresh map into thundermax.

 

When this occurs I always like to revert back to the OEM ECM to see if that fixes the problem, then go from there.
Bob

 

Ok changed the MAP sensor since the bike seemed to rev up when I sprayed the old one with carb cleaner. I also unplugged all the wires on the thundermax and replugged them all. Still running the same. Sprayed carb cleaner all around the intake and no real changes in how it's running. I don't have the stock ecm anymore and it has a different cam, exhaust, intake, etc so..... I'm not sure what else to try besides changing the remaining sensors. This thing is a nightmare. AFR on the Front and Rear is fluctuating between 15-19 (too much air) but the target AFR is showing around 13 and shows that it's in green range (WTF). I just don't get it. 11,000 miles and was running great when I parked it, I can't imagine what's happening.

New gas
New IAC motor
New injectors
Good fuel pressure 60psi
Checked all connections
New battery
Plugs look ok (gray to dark)
Flashed a fresh map into thundermax.
New MAP sensor.

 

Do a data log run and send it in to Zippers so one of their techs can take a look at it.

 

Contact Zippers and tell them your story, not had a Tmax myself but know a few that have and with some of them there were unit failures, new unit's where required, not saying that is what you need but a chat with one of their tech's sounds like the go, if you still had your stock ECM the bike would still start and run with it, good way to check if it's the Tmax having a hissy fit or not.

 

Did you take the fuel pump assembly out and hit the run switch? Mine would run fine with full tank but like crap when I ran low fuel level. I couldn't even reach 40mph. I took the assembly out and hit the run button. Stream of fuel shot out from hose. Replaced it and was back to normal.

I would still be poking around the fuel pump and regulator area as it seems to be the main suspect. I'm sure more experienced people will continue to chim in. Just my two cents.