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Rough Idle on Start Up

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Old 03-30-2011, 08:28 PM
  #1
norcoastal
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Default Rough Idle on Start Up

Lately my car has had a rough idle on start up.

Not always and not when its warm.

A few times when it happened the check engine light came on and went off in a day or so.

This is a very rough irratic idle. It's even hard to pump the gas to get the revs up when it's happening, I can but it's difficult.

My car has about 52,000 miles on it and it just started happening.

I've searched rough idle but haven't found anyting that seems simialr.

Any thoughts?
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Old 03-31-2011, 01:43 AM
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Remove the air box so you can look into the throttle body. My bet is that it is dirty and gummed up. Spray throttle body cleaner in there and clean it out. The car might be hard to start when you put the air box back on because of the throttle body cleaner, crank it and it will start, go for a ride around the block and it should be running better.
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Old 03-31-2011, 03:37 AM
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Try cleaning MAF as well.
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Old 03-31-2011, 07:25 AM
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I'll give it a try this weekend. Thanks
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Old 03-31-2011, 05:50 PM
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Check to see if the AOS or the AOS bellows is going. Look for oil drips etc... and check for vacuum at the oil filler cap.
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Old 03-31-2011, 06:43 PM
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ivangene
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check the oilk fill tube for cracks AND the oil fill cap (loose, bad o'ring)

just a simple idea
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Old 04-01-2011, 02:50 AM
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Any updates?
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Old 04-01-2011, 04:24 AM
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pro diagnostic will save time
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Old 04-01-2011, 08:57 AM
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I'm going to give it a look this weekend.

I hevn't had a chance to look during the week.

I'll keep you posted on what I find.
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Old 04-11-2011, 07:32 AM
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I'm going to have to take it to the shop. I sprayed throttle body cleaner and it didn't improve.

Check for vacuum leaks and didn't find anything.

Oh well.
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Old 04-11-2011, 08:28 AM
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My Porky is also experiencing irratic idle even after cleaning the throttle body. Have not tried cleaning the MAF yet and will do so immediately. Any other possibilities that causes irratic idle?
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Old 04-11-2011, 08:52 AM
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Step 1) If the car puts on the light it's stored a code. Pull the code and report back.

There's no point in people randomly guessing when you have data to help guide the diagnosis.

-Shawn
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Old 04-11-2011, 12:12 PM
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Coil packs.... Intermitten problem.
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Old 04-12-2011, 12:08 PM
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If that's the case he'll have stored codes for misfires helping him identify which cylinder he needs focus his attention on.
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Old 04-12-2011, 02:23 PM
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Originally Posted by r1de23 View Post
Try cleaning MAF as well.
+1
Had rough idle when the AC was off. Then got a CEL Yesterday. Went to Autozone and bought a cheapo OBD II reader. It showed P1123 and pending P1125. Looked it up on this board and it points to MAF.

Looked up cleaning procedures for the MAF and did that (about as tough as changing a light bulb).

Cleared the codes.

Engine now runs smoother and idles nice. No CEL.

I ordered a new MAF from GSR Autosport online. About $200. WAY cheaper than the quotes I got (over 50% cheaper). I'll put it in when I get it. Once again, its about as hard as changing a light bulb.
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