[11SEC]

Anyone experience engine hiccups while idling?

I tend to have this problem where I park and after a minute i hear a slight pop from the exhaust and the rpm raises to about 700-750


It even happens on startup where the engine stutters

[kctim]

Many have this issue. The car raises it's idle to 750 in a effort to reduce the misfire. How many miles on the car? Any recent work you've done to it? How old are the plugs? Any codes?

It could be: faulty lpfp/sensor, weak hpfp, vanos, leaking/failing injector(s), intake valve build-up, coils, spark plugs..

The common trend is to start replacing the cheapest items (plugs/coils) and move your way up to the expensive stuff. Good luck!

[11SEC]

Originally Posted by kctim

Many have this issue. The car raises it's idle to 750 in a effort to reduce the misfire. How many miles on the car? Any recent work you've done to it? How old are the plugs? Any codes?

It could be: faulty lpfp/sensor, weak hpfp, vanos, leaking/failing injector(s), intake valve build-up, coils, spark plugs..

The common trend is to start replacing the cheapest items (plugs/coils) and move your way up to the expensive stuff. Good luck!

Spark plugs are new and coils are a year old.

Car has 80K miles.

No codes and car pulls fine. The HPFP was replaced 2 years ago. I did the intake valve cleaning about 25-30K ago and I do spray meth.

[BoostedE90]

Another thing you can try that is cheap to do is clean your MAP sensors on the charge pipe and manifold. This temporarily fixed the issue on my car but the stumbling eventually came back.

[kctim]

Originally Posted by 11SEC

Spark plugs are new and coils are a year old.

Car has 80K miles.

No codes and car pulls fine. The HPFP was replaced 2 years ago. I did the intake valve cleaning about 25-30K ago and I do spray meth.

You can always start pulling your spark plugs to see if one is wet with fuel, aka leaky injector.

[shadow191]

Similar issue, but no rpm rise. Just every few seconds there will be a noticeable miss. Doesn't always happen, but it's more apparent when warm. Car has 42K on it, it's been doing it since I bought it w/ 35K a year ago. Plugs were changed 5K ago and the intake valves were cleaned 2K ago. The intake cleaning made the problem better, but it's still there. No other issues so I just don't worry about it.

[Rat_House]

I have the same thing. Intermittent rpm fluctuation and choppy idling, the car even shakes slightly. The choppiness is very noticible on cold starts now with a PE. Never any codes and i have noticed it goes away when i go to map 0 in JB4.