Engine braking
Engine braking I have a strange problem, I wonder if anyone else has had a similiar issue. I tried doing a search, and didn't come up with much. I'll try to describe it as best I can......
I have a 97 TA with an A4. Normally the car drives fine, and at highway speeds, if I let off the gas pedal, the car coasts fine....the tach stays right where it was when I had my foot on the pedal. But occasionally when I let my foot off the pedal, I feel a noticable engine braking. The odd part is, the tach is at the same RPM at the same speed (ie, 2000 rpm @ 62 mph). On top of that...when this weird engine braking is happening....when I come to a stop, the engine idles at a noticebly lower rpm (a tad over 500), and it stumbles a bit when I give it gas.
At first I thought it was a tranny issue (a tranny that was rebuilt 10,000 miles ago)....but....when the car is idling low, if I pop it in neutral, it still idles low....which makes me think it's an engine problem. I get no trouble codes, and the engine seems to be running fine.
Before I bug the tranny shop about a problem that may not be theirs, I thought I'd see if anyone here had any thoughts?
I have a 97 TA with an A4. Normally the car drives fine, and at highway speeds, if I let off the gas pedal, the car coasts fine....the tach stays right where it was when I had my foot on the pedal. But occasionally when I let my foot off the pedal, I feel a noticable engine braking. The odd part is, the tach is at the same RPM at the same speed (ie, 2000 rpm @ 62 mph). On top of that...when this weird engine braking is happening....when I come to a stop, the engine idles at a noticebly lower rpm (a tad over 500), and it stumbles a bit when I give it gas.
At first I thought it was a tranny issue (a tranny that was rebuilt 10,000 miles ago)....but....when the car is idling low, if I pop it in neutral, it still idles low....which makes me think it's an engine problem. I get no trouble codes, and the engine seems to be running fine.
Before I bug the tranny shop about a problem that may not be theirs, I thought I'd see if anyone here had any thoughts?
that sounds like Decel Fuel Cutoff is kicking in. That's how it feels on my car and I can confirm that's the cause based on scanning w/ HP Tuners. In fact I changed the settings on mine to enable earlier. Hope this helps.
Thanks for the replies. I don't see any mention of Decel Fuel Cut off (DFCO- I've learned from searching this forum) in the factory service manual, but I may not have looked in the right place yet. I'm not sure it would explain the lower idle I am seeing, did your car do that when you had the problem?
But it's a place to start looking! Thanks again!
-Rich
But it's a place to start looking! Thanks again!
-Rich
