Morning all. Little help here please.

My truck fired up on the first attempt this morning as it always does in early AM hours. However, today it started out at an very low loopy idle/tone. It wasnt harsh in the sense that it didnt make my truck shake or vibrate at all.

As I was watching the console for the CEL to illuminate (3-5 seconds later) the RPMs shot up to it's normal cold start range of 1200-1500 RPM sounding nice and strong then dropped down to about 800RPM or so and idled smooth.

My truck drove smooth, idled smooth and accelerated as if nothing had happened on the rest of my trip out.

Plugged my scanner in once I got to my destination and no pending/DTC existed.

Now the kicker is this has been happening on the occasion over the last few months but it would be a split second at low idle (not this 3-5 seconds) then jump to fast idle at the very first start. I have not had any runability issues at all during this period.

Kinda takes me back to the carburation days when the electric choke was not working or something.

-40 degree out this AM
-FPDM was changed out at 44k (3k miles ago)
-Fuel filter at 46k.
-I had no in cab accessories on.

Any help appreciated while I wait until work is over to start data logging or something. I'll get a video posted too.

 

Dirty, sticking Throttle body maybe? Try the diamond bird trick and see if that helps.

Lopey? Is your idle surging and or hunting?

 

Found a TSB. Not sure if its for the HDs

 

No it is not hunting for idle but it did not hit cold idle RPMs after it was first started. It took a few seconds. It sounds like it is lopey but the truck is running smooth during this "condition". For today, only during the first 5-7 seconds after ignition it sounded this way. Ran fine immediatly afterwards. I dropped it into gear once the RPMs came down and drove off with no issues.

Thanks but I do not think this is the case as I have been running the same tune since april with no issues.

 

I've had a tune on mine since new and had to have the pcm flashed to the new software level when it started running funny for the first 20 or 30 seconds after cold start then reinstalled my tune and haven't had any problems since.

 

Please see the video I uploaded.

You will see that my truck (cold soaked over night) starts up at about 800RPM . In this case, approx 1 sec (unlike yesterday as it took about 3-5 seconds) after ignition the RPMs jump to about 1200RPM and then dropped down to about 800RPM shortly after. Once my truck is fully warmed, it will idle at about 600RPM.

Please ignore the noise you can hear at approx 20 seconds. That is FM static from the radio.

I expected fast idle at every startup to some degree. What I do not expect is this delay prior to fast idle that I am seeing.

It was 17 degrees warmer this morning too.

http://s565.beta.photobucket.com/use...11-16.mp4.html

Compare this to the quick youtube reference I pulled. Not the best example I know.

http://youtu.be/URzGV0i9ovg?t=1m10s

 

No tune stock truck. 35 degrees out. Jumped from one notch above the 1. Now warming up at one notch under. 2006 Crew 82k miles.

 

Mine on almost every start is jump to 1800rpms then slowly drops back down to around 1000rpms and as motor warms up keeps slowly dropping down to around 600-800 range. This has been since its gotten cool outside. When it was warmer it barley cranked up to 1200rpms on start and down to 500-600 range pretty darn fast! But unlike the op mine does have a slight vibration. Still unsure what this is.

 

do you have a thick oil in ? maybe MAF sensor needs cleaning ?

 

Yes but does it start off low then go high?

5w-30 Royal Purple changed in July. Not even 1K on the oil. I did clean the MAF and throttle body about 6 months ago and since have put maybe 500 miles on them.

Now...I did take a look see at my MAF, looks like a single wire is missing it's jacket at the connector therefore being exposed to the elements. Perhaps that could be my scape goat. But as everything runs fine afterwards, I do not know what to think.

My truck sees maybe 20 miles a week. But those are hard fast miles. Texas has the fastest *LEGAL* highway in the states now. 85MPH toll roads.
http://abcnews.go.com/US/wireStory/n...texas-17550262