I have an '01 FLHRCI with 45,000 miles that I bought brand new. When I started riding in the Spring this year, the bike wouldn't idle when cold. It would just lose rpms and die. Once the bike was warm, it would run fine. In fact it was such a minor problem that I forgot to mentioned it when I took the bike in for the 45,000 mile service. The tech caught it and said it needed a new air temp sensor, which they didn't have in stock.

So I took the bike back when the part came in, and they installed it. Everything seemed fine.

Not to long afterward, I noticed that it seemed to have a flat spot at maybe around 3K rpms (no tach). I noticed that sometimes when I flip on the kill switch before hitting the starter, sometimes the fuel pump doesn't make that nice high-freq whirring sound. The tech heard it too. The FP doesn't make the odd sound on the first power-up, but will if I shut off the ignition and turn in back on again. Maybe it's just that the second time the fuel line is already pressurized, but I have spent many thousands of hours in the saddle on this bike, and tend to trust my instincts when I notice a noise - something had changed.

This time the tech said the EFI was dumping too much fuel in and fouling the plugs (it felt like too little fuel to me). They recommended a new fuel pressure regulator.

So they called today and said the bike was ready. Except that when I went to leave, it started hard, wouldn't idle, and still had the stumble problem. I took it a few miles up the road to get some clearer symptoms:

At partial throttle in 1st gear, it goes flat at about 20mph. Shift into 2nd hold at partial throttle and it happens at about 35mph. Less pronounced at higher gears, but the bike runs slightly rough in 5th at 55mph. If I crank in more throttle while running up through the gears, the problem is much less noticeable.

The wrench who worked on it is very good. He's worked on my bikes for 10+ years and knows his stuff. What could be going on that's tripping up a good tech? I saw some posts about getting water in the ECM holder. I've ridden through some horrendous rainstorms and have never had it act like this. I certainly washed the bike during all this, but never with much pressure.

I've read the threads that talk about the different EFI system on the newer bikes. The service manager at my dealer said the EFI my bike has can be a nightmare, which is why HDI switched. I hope this thing doesn't turn into a money pit...

Appreciate your ideas.

PL

 

That sounds like a throttle position sensor that has become erratic. I have that EFI system on my 2000 R/K with 43,000 miles and it may not be the best but it is not a nightmare. I do my own ajustments.


adjustin the TPS without a scanalyzer..." By meks from Biker Heaven

(Use the section for reading the TPS voltage and look for erratic voltage displays.)

I thought I'd post this cause of how much discussion has been done on this topic and how most think they can't adjust it without a scanalyzer so here goes...
with the motor cold...

make sure the throttle cam nut is tight and that the throttle cam assembly n shaft doesn't wobble around like somethings loose when u open/close the throttle...

take a look at u'r TPS's 3 wire connector, one wire's Gray/Violet, one's Black/Wht, one's Red/Wht...

disconnect it so u can easily get to the back side of the connector on the wiring harness...

cut a small diameter sewing needle in half so it isn't too long and stick it into the back side of the connector in the hole where/with the Gray/Violet wire goes into the harness...

push it far enough in so u know it's making contact with the actual terminal that's crimped on the Gray/V wire inside the connector...

now plug it back in to the TPS...

turn your digital volt meter on to read DC volts...

turn the ignition on, without starting the motor...

take the RED lead from the DVM and touch the sewing needle, that's now u'r back probe to read voltage output...

take the BLACK DVM lead and touch a bolt head or any good ground...

it probably reads somewhere around .50 volts...

ease the throttle to wide open and watch the voltage rise to about 3.0 or so, ease it back closed and make sure it still reads that .50 or whatever it did before u opened the throttle...

adjust the set screw on the throttle cam ( not the T10 hot idle screw u can reach through the air cleaner backing plate ) to where the voltage reads .61

shut the ignition off and remove the ecm fuse for a cpl minutes...

install the ecm fuse and warm the bike up to about 250 degrees...

now adjust the hot idle screw to inbetween 950-1050 rpm's...

just for the hell of it remove the ecm fuse again for a cpl minutes...

put the bike back together to ride into the sunset...

 

I wouldn't venture to guess that's what the problem is in this case, but it's certainly plausible. The TPS is pretty much the equivalent of the volume **** on a radio. Ever have an old radio or stereo that would crackle and pop through the speakers whenever you touched the volume ****? The moveable contacts inside can get oxidized and cause intermittent electrical connection. With the radio, you can often clean them up by running the **** full stroke back and forth several times quickly. It is worth a try with the throttle as a means of checking the TPS. But it is not a fix.

Also, if/when checking the voltage during a sweep as described above, it's better to use either an analog meter, or a digital one which has a bar graph, since the numbers may jump around too much if there is a problem with the TPS. Unless you travel extremely slowly, you might not catch a lightly intermittent connection with just digits on the meter. The bar graph or needle should move smoothly but won't if there is a problem.

 

Thanks for the ideas. I'll let you know what comes of it.

 

This is embarrassing....

The fuel regulator was indeed bad, and that contributed to fouling the plugs.

But the real problem was a filthy air cleaner. I took an 8,000 mile, 28-day cross country run with some guys last years, and it still had the same air filter on it. None of us looked for the obvious....

 

The fuel regulator was bad. Did you replace the TPS or the fuel pressure regulator?