Hey guys. This just started happening out of the blue. After the truck has sat for a while (Through the night or during work) it cranks up but dies right away, or runs erratically. It's as though it's not getting fuel. If I apply just a bit of accelerator, it runs fine. The rpm's are down to 500 when this happens, as well. (From about 950 at idle normally.) Once I get it running, it idles low and doesn't recover. It will die when I put it into gear while this is happening. Once I have driven it a few miles, it clears up and starts up fine.

Last week it did this for 2 days and then quit. I changed the oil last week and decided to replace the fuel filter, while I was at it. (Hoping that was the culprit.) I also ran the fuel down to almost empty and got fuel at a different station in case that was the problem. Well, today it's back after 4 days of running fine.


Anybody have any idea what this is? Has anyone else had this happen to their Lightning?

 

BTW... No codes.

 

Try cleaning the IAC valve.

 

I think you're right. I hear a clicking sound when it's idling badly, too. I'll just get a new one while I'm at it. This one has 6 years of daily driving on it. It's about time for a replacement anyhow. It took a while to find it. I didn't install my Whipple myself and the IAC valve is relocated under the throttlebody on the intake tube. I had a loose vacuum line leading into the IAC, too. I wonder how much that would affect things?

 

if it was loose enough to leak, it could cause problems, but I dont see that fixing its self when its warmed up... Try the iac first

 

Just gotta get the part. I'm sure that's what it is. Thanks.

 

Mine does it all time when truck has not been started up for a while i can start it up and take my foot off of throttle it idles just fine if i try to gas it it dies.When it idles about a minute its ok but my lightning is heavy modded with JDM built motor i been told we should not be concerned. So i don't worry about mine it runs just fine