1997 Throttle position sensor setting
My bike has nearly 79,000 miles on it and it has a 1550 kit (Stage II).
Recently, it got to where is had a constant miss/surge at any constant speed or RPM.
After doing the normal tune up stuff I took it to an indy shop and he thought it was leaking intake seals so I had him install them.
Seemed like it was better for day or two (probably my imagination).
I purchased, and installed a new TPS and simply set it to where the engine would maintain about 1000 RPM's at warm idle, however it still had the same miss/surge at constant speed/RPM.
Back to the shop.
Indy checked all wiring and finally got the bike to "code" after installing a new Engine Temp Sensor which indicated that the ECM was defective.
He ordered a new ECM (which I think he says has been updated about 5 times since my bike was built) and also a new "flash" update for the Stage II.
The new ECM has a USB port that requires updates to be done via a laptop computer.
I've been riding the bike for about a week to see what I think it needs and will take in back after the weekend for some "tweaking".
The bike runs better (so the new stuff defnitely helped) but is still not perfect but the indy (who took a 40 hour class on the MM EFI system) believes that it is now a matter of syncing the TPS to the new ECM and obviously this is not just a set to a certain spec and that's it.
It's more of a of trial and error thing and getting it dialed in correctly.
I'll update IF an WHEN we get the bike running good.
Good luck.
Was in contact with a S&S VFI ECM owner a fews year ago and happy with it, not alot of info as a carb conversion overrode the costs of VFI and a tuner, it has alot of features including adjustments like todays Mastertune and Powercomander so keep everyone informed
Was in contact with a S&S VFI ECM owner a fews year ago and happy with it, not alot of info as a carb conversion overrode the costs of VFI and a tuner, it has alot of features including adjustments like todays Mastertune and Powercomander so keep everyone informed
Copied this from someone smarter than me, I have a 97 ECM if that is a direction you need to go.
First, back out the warm and cold idle screws so they're not affecting anything. Then disconnect the ISC actuator.
Backprobe (with a pin or anything small like that) the right-most wire on the TPS connector. Connect the positive lead of your multi-meter to that pin; ground the negative lead. With the ignition on and the engine cold, rotate the TPS until you get a voltage reading of .275. Tighten the screws being careful not to change the reading.
Next, turn the cold idle screw in until you get a reading of .60 to .64 volts.
Next, turn the warm idle screw in enough so the bike will idle. Warm the engine, and adjust warm idle to taste (about 1000 rpm's).
1. The TPS adjustment screws were epoxied so they couldn't be adjusted. I had to pick/dig/scrape/cuss them until I got them clean enough to get a T15 TORX socket in there. Not hard, just annoying.
2. When I made the adjustment, I loosened each TPS screw one at a time, then retightened until it was just snug. To make the adjustment, I gently tapped on the TPS bracket with a very small hammer and watched the voltmeter as I did it. I hit the magic .275 pretty quick and easy then tightened the screws and rechecked the voltage.
3. The recommended cold idle voltage of .640 above will give a cold idle rpm pretty close to the hot idle rpm. When I got my bike buttoned up and started it, I turned up the cold idle screw so the rpm was around 1,500. Just my preference but I could see where it would be annoying to others.
My bike was popping through the exhaust just a little inbetween gears. After I adjusted the TPS, that went away. The initial voltage at the TPS after I removed the ISC actuator and backed out the hot and cold idle screws was .18. I don't think this is out of range enough to throw a code but it was giving me that annoying little pop between gears. One of the TPS screws was barely snug when I first loosened it too. It probably moved a little from vibration. If I have to adjust this again, I think I'll change to allen screws and put locktite on them to boot. Yeah, should have done that this time.
Carl
PS. Good thing you're in the EVO section. Otherwise you'd probably be getting a note from the thread revival patrol.
The Best of Harley-Davidson for Lifelong Riders
PS. Good thing you're in the EVO section. Otherwise you'd probably be getting a note from the thread revival patrol.
I hope someone smarter than me chimes in.







