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Bad TFI module? FI1252st

tunes

Member
Hello,
we have an 08 streetglide that was running great, made no changes to bike and overnight it started running like its running out of gas. It will idle ok for a bit right at 1000rpm but it will not run without missing between 1200-3k, over 3k it runs fine just like always. Im guessing the TFI is bad? if I adjust any of the pots it seems to run better briefly then goes back to rough. Happened to be at dealer when it started to do this and he pulled it in the shop plugs are ok and no error codes. He thinks it must be going bad(not familiar with the unit). Is there any way to reset this unit or check it without sending it back?

I guess it could be bad gas but Im half way through the tank? We were caught in heavy rains but it ran fine for 5 days after that.

Can I remove the TFI and plug the factory module back in and see if it runs smooth, I have added stage one so factory setting wouldn't be optimal.

At a loss as to where to begin troubleshooting it.
 
Disconnect the ground lead for the TFI and see how it runs. Don't assume it's the TFI either, there's many sensors it could be too including the fuel line and even the fuel pump or filter being cracked. There was a number of these.
 
Couple of options to see if it is the TFI before you pull it out and send it back to Dobeck.

Write down the TFI settings, then do one of these:

  • Like Glider said, disconnect the ground wire for the TFI
  • Set the first three pots to 1 (counter-clockwise all the way - off), and the last pot to 11 (clockwise all the way). This is effectively OFF for the TFI. See how the bike runs now.
  • If you really want to be sure, disconnect the TFI injector connections and plug the Factory connector back in. Now the TFI is completely out of the loop and CAN NOT be affecting the engine performance.

Whichever of the three options above was chosen, if it did not make any difference, then it must be something else. As Glider said, there are a number of sensors that can mess up, bad gas, clogged filter, broken fuel pump housing, pin-hole leaks in the convoluted tubing inside the tank, etc.

TQ
 
Well I emailed Chris at Dobeck and he says if I remove the ground from his unit that will take the TFI out of the bike, the bike will run a little lean but not cause any damage and if it runs ok then the TFi is bad and I can return to him and he will try and repair it.




Thanks about the tip on the ground you guys are amazing! . My bike was made late in the year so it should have newer casing but didnt know about that report. I did get a new fuel filter and will swap that out tonight when I get home.
 
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ALSO, If you would,,, Please get back to us on THE FIX, many here Need to Know the Results... Thanks!

signed....BUBBIE:D
 
Yes, I have the same TFI in my 09 FLHX & would be curious to see if it was a defective unit in case I get similar symptoms. Wouldn't rule out glider's input on fuel pump & filter issues...Thanks!
 
Ok pulled the ground turned pots down like Slider and TQ suggested, bike still ran poorly. So I guess the TFI is ok. I pulled the pump and it looks ok no stress cracks, I put in the new filter put it back together and went for a ride. It ran great, no mis-idle or stumbling took it up on freeway and good to go. On my way home for my victory cigar.....it started doing it again, this is after about a 45 min ride. It doesn't like to run between 1000-2000 rpm. I still have the same half tank of gas in there?

Any suggestions other than dumping the gas?
 
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