Randomly running like crap???

[fireman68]

My 2003 1500 FI Nomad has a problem that I have been fighting for the second year now. It occasionally runs like crap, sputtering and not wanting to run when taking off from a stop for quite awhile when first starting it up. This can last a 1/2 hour or sometimes even longer regardless of the outside temperature. It will run ok at higher RPMs, but cruising at low speeds (first or second gear) and taking off from a start it will miss, sputter and sometimes even die before I get going. This also only happens every once in a while. Most of the time it runs fine.
This all started last year only it happened more frequently then. This year it hasn't done it much until the last few days it started up again. Earlier this year I rode it from Indiana to Connecticut and back and it ran great. So I was starting to wonder if my lack of riding time had just gotten it loaded up and the road trip had gotten it blown out good and it was running good, until it all started again this week.
Whenever it starts doing this I have done all the suggestions, cleaned the throttle body, checked for vacuum leaks, checked electrical connections, etc. and none of it helps. (the battery is also new)
I am completely at a loss on what the problem is. It is getting very frustrating not to mention dangerous (if I would happen to try to pull out in traffic and it would sputter and die). I would take it to a shop to get looked at but there isn't one very close to where I live and with the problem being random, there is a chance that it may not do it for them. I really like the bike, but it's getting to the point where I am about to get rid of the dang thing. Any suggestions would be appreciated.

Bike specifics- 2003 1500 fi nomad, Chuckster's single intake with air cross-over and cold solenoids removed and coaster plates, Vance & Hines dual exhaust, Dobeck TFI fuel module

[dank]

I'd put everything back stock and see if it still did it.

[Idaho]

Sounds like a vacuum leak but I'm at a loss for how it would come and go.

[cnc]

Can you unplug your fuel processor and try it without it for awhile? Another fella on here had similar issues and it turned out his was crapping out. I don't remember what brand his was.

[MJ07Nomad]

My guess would be fuel, but not sure where to start. I would also check the V and H rear pipe and see if it cracked, clean the throttle body again and use the Seefoum Spray. Also where the air filter plate goes against the body there is a seal there it maybe missing or not sitting right.

[Jeffsmountainauto]

I would assume that a problem that is intermittent would be electrical. I would remove the fuel processor and see if the problem goes away. Any sensors going out of range can have adverse effects on the fuel mix as well. Throttle position, water and air temp.
I am not certain, but i would assume that the simplicity of these fuel injection systems would only allow them to catch a sensor related issue and turn on the fi light if the sensor was totally open circuit or disconnected. That being said, even if it didn't act up, a decent tech may be able to catch a glitch in any of these sensors and correct the problem.
I would start with aftermarket parts first though, and disconnect the fuel processor to see if the problem goes away. Good Luck.

[davidhollinger]

These posts are the reason I want to keep my bike stock.... no new pipes or TFI or intakes. Just ride it right out of the box. This doesnt include any chrome though! :)

[recumbentbob]

Originally Posted by cnc

Can you unplug your fuel processor and try it without it for awhile? Another fella on here had similar issues and it turned out his was crapping out. I don't remember what brand his was.

I remember that; I think it was a Cobra fuel processor.

[fireman68]

OK, so on the way home yesterday, it ran perfectly fine. This morning, it ran fine except for at some stops the idle would be too low to want to keep running. a couple times if I gave it a quick little rev it would settle down at the correct idle. The rest of the time I would have to hold the throttle open a little to keep it running and then a few other stops it idled fine. When it is warmed up and running ok, I have the idle set at about 1000 rpm. I haven't had a chance to try unhooking the TFI. I am assuming that to do that, I need to completely unhook it from the injectors.?.

As far as checking loose or bad wiring, any suggestions on where to start?

I did try checking for vacuum leaks with an unlit propane torch and found none.

[lar]

No need to disconnect your tfI just turn the settings on your Dobeck to one and it will be shut off.

[Silent Sam]

..Well not being there it might be some sort of actual tec-o-crap problem...
BUT I BET you got some contaninated gasoline about a year ago..or continue to get some ! ?
If you wash the bike..or live in an area of high humidity..the odds are high you have some water in the fuel tank...

Quickest and Easiest Fix I can recommend... SEA FOAM (a fuel system tune up in a can)

It wont hurt to try it, I use it a lot on the long road trips I take...It has always "worked" for me, to smooth out any rough running...so far !

[ringadingh]

Originally Posted by cnc

Can you unplug your fuel processor and try it without it for awhile? Another fella on here had similar issues and it turned out his was crapping out. I don't remember what brand his was.

That was Rhys with his Power Commander. I also had a chafed wire running from the TPS sensor to the Power Commander a few years ago that gave me similar problems.

[ringadingh]

Originally Posted by fireman68

OK, so on the way home yesterday, it ran perfectly fine. This morning, it ran fine except for at some stops the idle would be too low to want to keep running. a couple times if I gave it a quick little rev it would settle down at the correct idle. The rest of the time I would have to hold the throttle open a little to keep it running and then a few other stops it idled fine. When it is warmed up and running ok, I have the idle set at about 1000 rpm. I haven't had a chance to try unhooking the TFI. I am assuming that to do that, I need to completely unhook it from the injectors.?.

As far as checking loose or bad wiring, any suggestions on where to start?

I did try checking for vacuum leaks with an unlit propane torch and found none.

It sure sounds like a vacuum leak from the way you describe it. I'd takea closer look again.

[fireman68]

This is where I am at so far.
I changed places where I usually got gas here in town (Supertest) to Super Pantry (Phillips) or BP (Mobile) which is the only name brand choices I have. I haven't "really" had any trouble since. The bike has been running well. I have taken some day long trips and several short rides to work without any problems. The only thing that I have noticed now is if I don't let it warm up (3 or 4 minutes with high idle knob pulled) before I ride it, especially now that it is getting cooler, it still wants to stumble a little at idle. But the main thing is the different gas seems to have made a difference.


By the way I have been running 89 octane without any pinging since I switched also.

[macmac]

Run the lowest octane you can get.

Check the wiring harness at the frame side where it turns down behind cly 2 under the gas tank. IF the wire tie is still OEM it had a release tab so do not cut it.

make sure that if you do this you pull the harness down from the frame and LOOK there for chaffing and any wires that have chaffed into the frame.

If this happened you will get all sorts of crazy shit happening. To turn off a TFI just set all pot counter clock wise. I doubt it is the TFI, but with colder weather the ECU will blow more fuel cold. The past 2 days my bike stalled once because of my wrist letting it and once because my bride got the bright idea I needed help getting out of the barn backing and she pushed on the sissy bar while she was inside the barn still and she was about to get caught in my hi way pegs and jammed.

Sometimes I just don't know what gets into a woman's head. Anyway the ECU can be lied to after a cold enough night. For example it was 31 here last night but in the day time temps it was about 54 when I fired the bike up. I bet the ecu was seeing 31 still.

Another thing you can try is let the engine warm up and then set the idle as fast as you can and still have a decent idle for in colder weather. I just hold the throttle or lock it and have never used the pull knob yet once.