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2005 Express, Rough idle, CEL flash

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Old Nov 12, 2013 | 11:16 AM
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Default 2005 Express, Rough idle, CEL flash

Hello Gentleman... Had an odd experience the other day after a day out driving the 1500. I was waiting in line in the In N Out drive through- Probably a total of 8-10 minutes. After about 5-7 minutes, the idle started to get a bit rough, then even rougher.. Nowhere near stalling out or bogging down, but enough to cause concern being that this van has been a perfect champ for years. What really freaked me out was when the CEL started to flash, so I immediately killed the motor with the key.

After a minute I started it back up and it was back to running fine, no CEL. Drove home fine ( 30 miles ) and no issues since, but i haven't tried to re-create the symptoms again either.

The Chevy manual reads that a flashing CEL represents a misfire, and simply tells you to shut off the motor and turn it back on after a few minutes. I did hook up my OBD and it will not connect to the ECU... I tried a few times... Wierd. I have'nt ever run codes on the van before, is there a secret step im missing?

Any thoughts ?

Thanks!

-Grae

Last edited by endneu913; Nov 12, 2013 at 11:38 AM.
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Old Nov 12, 2013 | 7:18 PM
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Pull your distributor cap and look for oxidation on the 8 points. Clean up with emery cloth and clean up the rotor as well.
Check your spark plugs are iridium plugs, and replace if not, or if not in good shape.
See if that cleans it up.
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Old Nov 14, 2013 | 11:40 AM
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Silly question, do i HAVE a dizzy cap? Ive done basic tune ups on this rig, and was perhaps remembering incorrectly, i thought it had coils.
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Old Nov 14, 2013 | 8:00 PM
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Sorry, I mis read the year of your van. Yes, you have the newer v8's which I have not worked on.
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Old Nov 14, 2013 | 8:24 PM
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You're not missing a step. See if there is anyone else that can help you pull code. But best bet is to try and recreate problem to see if it indeed will happen again or if it was just one of those fluke things.
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Old Nov 16, 2013 | 12:08 AM
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Originally Posted by Tech
You're not missing a step. See if there is anyone else that can help you pull code. But best bet is to try and recreate problem to see if it indeed will happen again or if it was just one of those fluke things.
Yeah, weird... should just plug it in, turn to key to On, not start, and press some buttons!

Thats a good idea.. i will do that.... let her idle for a while and see.
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Old Aug 7, 2014 | 12:50 PM
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So, almost a year later and im still dodging this problem- LOL- It hasn't given me really any trouble until a bit now-

The other day I noticed that after driving, I went to put in park and the idle dropped to almost non existence, stumbled and died. Hasn't done this since, either, but it does continue to idle super low when I put in park. Almost to the point of dying. But it will start right back up with now problems either way

No CEL shows.. .Van runs strong otherwise.

Thoughts? Perhaps something funky like an Idle air control Valve or something?

About to do a 2400 mile road trip and want to get this nailed down.

OH, also, it does idle a bit rough after sitting for a few minutes, like i mentioned in my first post

Thanks!
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Old Aug 10, 2014 | 3:45 PM
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Don't focus on the fact that the engine light has not come on. Lots of codes can be read and stored in the computer without triggering the CEL. If you have not taken it to a shop and have a full size, (not handheld cheapie) code reader check your computer, then do so.
What you describe is likelu caused by one of the many sensors on that van. Throttle position, crankshaft position, campshaft position, etc.....
If it was an older van i would be guessing a vacuum leak. In you case maybe an airflow sensor.
Too many to list or guess.
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Old Aug 23, 2014 | 8:14 PM
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Well, things are looking worse.. Its starting to idle very low and completely die when shifting from P to Drive... I had to restart it about 10 times just to get back in my garage.

Its saturday, so im kinda screwed on taking it to a shop, if i could even get it there to read code and check it out. Was going on a road trip on monday, but i guess not now.
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Old Aug 24, 2014 | 12:00 AM
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And It seems the problems are resolved.

I removed the Intake plumbing and found quite a bit of black residue, cleaned this up with some B12 Chemtool... Also, pulled out the Air Idle Control Valve and cleaned it like crazy with the B12- One of these did the trick! Motor is running back to normal now.

Ill keep an eye on it thought.
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