Idle dropping while coasting?
Discussion
Hi there,
Had my MX-5 a few months now and it's recently started developing this odd little quirk whereby, upon releasing the clutch and coasting the last 3-5 feet before, say, a traffic light or a parking space, the idle is dropping from around about 900 to sometimes as low as 400 for a few seconds. The car seems as if it's about to stall, but never does - blipping the throttle seems to help clear it up although it usually sorts itself within 2-3 seconds and reverts to the normal idle speed of 850-900.
Anybody know what might be causing this, or have had any similar problems? It gets better as the car warms up on a longer drive, but its quite disconcerting coming up to roundabouts etc! Oil level is good as are all others and spark plugs were changed when I bought it for some decent ones. Still on original HT leads.
FWIW I've fiddled around with leads and plugs to see if it was a loose connection but doesn't seem to have made a difference. Engine performs completely normally and doesn't feel down on power!
A case of, "they all do that, sir"?
Thanks in advance!
Had my MX-5 a few months now and it's recently started developing this odd little quirk whereby, upon releasing the clutch and coasting the last 3-5 feet before, say, a traffic light or a parking space, the idle is dropping from around about 900 to sometimes as low as 400 for a few seconds. The car seems as if it's about to stall, but never does - blipping the throttle seems to help clear it up although it usually sorts itself within 2-3 seconds and reverts to the normal idle speed of 850-900.
Anybody know what might be causing this, or have had any similar problems? It gets better as the car warms up on a longer drive, but its quite disconcerting coming up to roundabouts etc! Oil level is good as are all others and spark plugs were changed when I bought it for some decent ones. Still on original HT leads.
FWIW I've fiddled around with leads and plugs to see if it was a loose connection but doesn't seem to have made a difference. Engine performs completely normally and doesn't feel down on power!
A case of, "they all do that, sir"?
Thanks in advance!
Have you checked the coil pack as well?
I had a similar problem and tried the icv, as sean suggests, but it still did it.
Realised that on of the coil packs where the ht lead was attatched had been blown apart, so it wasnt connecting properly. New coil pack and i havent had the issue since.
I had a similar problem and tried the icv, as sean suggests, but it still did it.
Realised that on of the coil packs where the ht lead was attatched had been blown apart, so it wasnt connecting properly. New coil pack and i havent had the issue since.
It's not normal and they don't all do it. It is something that can be sorted.
Cleaning out the idle valve is the first step followed by checking/resetting base idle.
If that doesn't sort it then there are a number of other things to check - temp sensor in the back of the block, coil pack, AFR, O2 sensor etc...
Cleaning out the idle valve is the first step followed by checking/resetting base idle.
If that doesn't sort it then there are a number of other things to check - temp sensor in the back of the block, coil pack, AFR, O2 sensor etc...
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