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Loss of power on deceleration

J

JustJane

New Member
Hi everyone,

I've got an 04 Heritage Softail. I installed an Arlen Ness big sucker air intake & put on Vance & Hines straight shots at the end of last summer. Noticed it would lose power after going down the highway for awhile & when I slow down for a corner or stop sign she wants to die. Riding down the highway or in town is fine. No troubles. It's only after going at higher speeds & then deceleration this happens. I've got to keep the RPMs up or she'll die.
Thought maybe it was a computer issue. Went yesterday to HD dealer & had a Screaming Eagle Race Tuner installed. Thought my problem was solved. Second slow down after leaving the city....losing power!!! I'm at a loss. Any input would be great :)
 
As you had a SERT installed, we know you have fuel injection. Delphi f.i. Idle Air Controllers (IAC) , have a tendency to get gummed up with oil from the crankcase ventilation ports in the air cleaner assembly. IAC 's don't cost much, and are easy to replace. There is a easy cleaning that can be done for $5 if you want to try it. The cleaning used to be in our Tech tips, but I think that area no longer exists. I'll wait and see if other members have a different diagnosis or ideas before I type the thing.
 
I agree with what Breeze said above. The stumbling and dying at idle after higher rpms is pretty common when the IAC is gummed up. I have tried cleaning mine many times with only limited improvement for short periods. I second the suggestion to replace it and see if that solves the problem. It is an easy and inexpensive fix.

If that doesn't fix the symptoms, then we will try other things.

Cheers,

TQ
 
As suggested try clean the IAC. Remove the air cleaner so the throttle opening is exposed. Stick a small rag in against the butterfly, look at about 12 o'clock in the throttle snout, you should see a hole. spray some good carb cleaner in the hole and that should clean out all the oily gunk that gets in there.
 
Thank you guys for the help. I'm going to try & clean this IAC & will report back in the next couple weeks if it's fixed the problem :)
 
JustJane said:
Thank you guys for the help. I'm going to try & clean this IAC & will report back in the next couple weeks if it's fixed the problem :)
Click to expand...

I did that at first on my '03 Ultra Classic. It would make a difference for a couple of months, and then I would have to do the cleaning again. I rode the bike daily as long as the weather cooperated!

I finally gave up cleaning and just replaced the IAC. Fairly simple and inexpensive fix. I did that in Nov. 2012 with 95,700 miles on the clock. That lasted over 4,000 miles until the bike was totalled by a collision with a cager going the wrong way on the 59 HOV in Houston - May 2013. Not sure how long it would have lasted otherwise!!

Good luck either way.

Cheers,

TQ
 
I had the same problem on mine. '04 Heritage with a SERT. Thought I had a TPS problem. If you have the ability to, I'd run the SERT Data Mode and look at the TPS voltage is at idle, and see what the lowest MAP number is. If the MAP (manifold air pressure) is below 13 it won't stay running. Turned out my problem was a corrupt file. Can you have it re flashed? Do you have a PC or Laptop you can connect it to? Who's the SERT experts here? I'm chasing a 2deg Knock Retard and a Rev Hang.
 
Unfortunately our go to SERT expert recently passed away and i'm not sure who else may have the answer you need.
I had a pretty good spark knock on my Ultra Classic and installed the SERT on mine. After retarding the timing a few degrees it took care of the issue.
 
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