Rough start when recently running

[RamFan]

Hey guys this is in regards to the Charger.

I noticed three days ago when I stopped by my mailbox I shut off the car (mailbox key on the key ring), checked the mail and when I went to start it again it took a couple more turnovers than usual before it would start.

Yesterday after making a trip to the grocery store I stopped off at work for a couple seconds and when I came out I experienced the same thing.

Today, I went to the store then since I'm being lazy today I took it through the local touchless wash. While I was in line at the wash I turned the car off while one car was in the bay. Went to turn it on to pull up a slot and the same thing happened, pulled up my one slot to the ticket machine and turned off the car again since I had to wait for the car in front of me now. Once that car was finished up I started her up to pull into the bay but experienced the same thing. Now in the bay, this is the weird part, I turned the car off let the wash do its thing and went to start it up afterwards and it started right up, no staggering at all.

When I start it up for the first time of the day it starts right up. I had this happen on an '88 F250 once and it ended up being a combo of ignition coil and the computer. I have a hard time believing this could be the case on such a new vehicle. Anyone have ideas?

 

[Chris142]

any coolant loss?

 

[mechtech2]

Could be a coolant or air temp sensor.
Actually, most sensors could cause this, even MAF.
Any vacuum or intake leaks? PCV system?

 

[TallPaul]

I had a similar problem on my '95 F150. Any time it was in the hot sun it would not start well, but if I parked in a garage it would start fine. Also, I discovered on a hot sunny day, I could open the hood for 5 minutes or so and it would start fine. The paint was dark blue.

 

[Bgallagher]

That's what you get for not washing the car yourself! jk

It could be so many things, it is hard to narrow it down to just one thing. Check with the dealer. There might be a TSB out for it. Assuming this isn't an isolated incident...

 

[RamFan]

No coolant loss. No idiot lights pop up. I'll have to look into the TSB listing, last I looked I don't recall seeing something about this issue but I'll double check. It drives just fine other then this issue that just started happening. I'll have to hook it up and see if any codes show up.

 

[Kruse]

I've had a vehicle in the past that had a couple of injectors bleed down. It would start okay after sitting for a few hours because the vapors had evaporated, but sitting for only 10-15 minutes would have a rough idle for a few seconds.

 

[artificialist]

Your IAC passages might be dirty. It caused random hard starts with my dad's 1997 Lexus ES300, and it has happened to many other people driving many different cars.

Also, some cars act weird if started, driven briefly, and then restarted. The computer sometimes resets things like the fuel trim, spark trim, IAC position, and DBW throttle stuff, depending on the car design.

 

[RamFan]

Looked through the TSB listing and there does appear to be a TSB for the MAP sensor that can cause four codes to pop: P0652, P0340, C121C, P2127. Guess I'll be making a trip to the dealer and have them scan it and see if anything pops up. Not looking forward to that trip.

 

[mechtech2]

Go get a free scan at an auto parts store, first.
They may pull some hidden codes, and you can go from there.

 

[440Magnum]

Is the weather getting hotter? Have you filled up recently, or is this maybe still a tank of winter-blend refinery waste high vapor pressure swill? Or maybe your station still had winter crud in their tanks? My 01 Cherokee does pretty much what you describe when the weather gets hot and its still got winter fuel in it (00-01 Cherokees are so bad about this that there are TSBs to add insulating sleeves to the injectors and fuel rail). Its basically the same as vapor-locking in an old carbureted car- the fuel forms bubbles in the fuel rail and injectors and the fuel delivery is unpredictable until the bubbles purge out, causing rough running.

Cooling everything down in the car was would make the fuel condense and everything would be normal.

 

[rationull]

I don't have an answer for you, but we have a Suburban with a similar problem. I thought it might be the fuel pressure regulator, but replaced that "while I was in there" doing another job a little while ago, no effect. The next guess is leaky injectors until fuel pressure bleeds down, but not worth fixing for us given we don't drive that vehicle much.

Good luck!

 

[RamFan]

I will definitely be going to an autoparts store first. Yes the weather is getting warmer, I'd say we finally reached stable spring/summer temps about 2 weeks ago. The engine doesn't run rough, it just starts rough in the sense that it doesn't start right up once its been running. On a cold start I'm looking at 2 or 3 cranks and she fires right up when already warm i'm looking at 6-8 cranks.

 

[anonobomber]

Do a "key dance" and watch the odometer or EVIC for codes. Turn the key to ‘ON’ (not start) and then ‘OFF’ repeatedly, in this order: ON-OFF-ON-OFF-ON. All the codes will dump to your odometer. No need for a code reader.