L
laf
Guest
Hi there,
I've got a strange problem on my 1996 SL500 R129. The revs pulse when I maintain a speed with very little throttle. It's done it since I bought it 15 months ago.
I might be doing 40mph, tiny amount of throttle and after a short while, the revs will drop 100rpm then recover immediately: it's like the rev counter bobs. It will then continue doing this every couple of seconds until I move the throttle (even as little as 1mm).
It does it in any gear at any speed and with or without cruise control.
I've taken it to a local independent who've checked it over. The computer is showing no problems. They thought perhaps it was the air mass meter so I disconnected it. The pulsing was still there but the rev drop was more like 200rpm instead. I reconnected it and it's back to "normal" bobbing. The air filters are clean, the engine oil's changed a few weeks ago. The car was services about 5000 miles ago tops.
They also say it's running lean as the 9 month old plugs are still really white.
Does anyone have any ideas?
I hope so,
Lee
I've got a strange problem on my 1996 SL500 R129. The revs pulse when I maintain a speed with very little throttle. It's done it since I bought it 15 months ago.
I might be doing 40mph, tiny amount of throttle and after a short while, the revs will drop 100rpm then recover immediately: it's like the rev counter bobs. It will then continue doing this every couple of seconds until I move the throttle (even as little as 1mm).
It does it in any gear at any speed and with or without cruise control.
I've taken it to a local independent who've checked it over. The computer is showing no problems. They thought perhaps it was the air mass meter so I disconnected it. The pulsing was still there but the rev drop was more like 200rpm instead. I reconnected it and it's back to "normal" bobbing. The air filters are clean, the engine oil's changed a few weeks ago. The car was services about 5000 miles ago tops.
They also say it's running lean as the 9 month old plugs are still really white.
Does anyone have any ideas?
I hope so,
Lee