I figure I'd ask before I looked into it myself, a quick search didn't really yield anything either. Anywho... The last few mornings it's been fairly cold out (15*-25*F) my 07 SS/SC hasn't wanted to run after first starting. It turns over and starts but immediately dies, yesterday it fired right back up no problem. Today it died and I cranked a good couple seconds and it was obvious that it was having troubles getting going. Once it does start it runs fine, no problems. After sitting all day today with a high temp of 35ish it started fine when I left work too. I was swamped today at work and didn't have a chance to pull it in and look at it, so I figured I may as well start here. Not to mention it's always easier when I know what I'm after or at least have a good idea what to look for.

Any help would be greatly appreciated! Thanks.

 

something is off.
my car started first time every time through last winter.
and that included numerous days after sitting 14 hours while i worked a nightshift in -40*f

 

my 2.4 did the same thing for awhile but lately it has been fine..I dont understand it either and dealer had no idea either

 

That's what I'm afraid of, it only does it when cold so it'll be a pain to figure out. I just dealt with the same exact issue on a 98 Yukon a couple weeks ago, it took 4 or 5 days to figure it out (fuel pump allowing pressure to bleed off only when cold). I don't wanna have to be working on it for a week checking every morning, not that I can't, it's just a pain.

 

it's been pretty cold here, (60 one day, 30 the next.) car always starts right up no problem. i would say something is off, just not sure what

 

maybe we need a better battery and the CCA is too low

 

well, check the battery voltage. for normal startup shouldn't make a difference. 12.7 volts is 12.7 volts.

 

Ha mine won't ******* start at all it a peice of **** once the weather gets under 45 I hate my cobalt wish i'd never owned one.

 

Well alrighty then....... I love mine.

Back to the topic on hand, the battery seems to be doin fine seein as how it does start even after having to crank longer then normal, so I don't suspect the battery. I was thinkin maybe I've got an IAT sensor or CTS that's throwing off a random skewed signal that is causing it to not get the right amount of fuel. Guess I should have grabbed a Tech 2 and checked over the weekend, oh well.

BTW- Thanks for all the input so far!

 

Mine has been doing this for years. It's starting again this winter. Last time I had in to the dealer they said they replaced a coil module.

 

do you have a cold air intake? the air might be too cold for the combustion chamber to detonate efficiently. doesnt sound serious tho, its an 07 so i doubt your battery is at faul.

 

Mine is doing the EXACT same thing! It will either start then bog and shut off, or it just won't start at all sometimes. Then others it fires right up, no problems at all, and NO CODES. Yesterday it bogged down and almost shut off while I was driving up main street. Then all of the sudden it kicked back in and off I went.

I thought it was from having this new salvage engine put in, then I thought it was water in the gas. Now I'm wondering if I have the same problem as the rest of you???

 

Chris Rock said Robitussin will fix anything............

 

Im curious. are all you guys having problems running an oiled filter?

cuz im starting in -40 temps with 60lb injectors a CAI, and custom tuning, and its never skipped a beat once.

 

It's completely stock, haven't done anything to it yet, only has 6700 miles on it too. Guess I'll just have to diag it and report back, but of course it started fine this morning...

Robitussin? hmmmm...... May have to look into that. I wonder if GM warranty covers Robitussin?

 

Mine started doing it when it was completely stock.

 

Back to completely stock here.

 

Found this in dealerworld, it will give you an idea of what to look for .

Document ID# 1853611
2006 Chevrolet Cobalt
Hard Start

Inspection/Test


Action

DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies.

Preliminary

• Refer to Important Preliminary Inspections Before Starting in Symptoms - Engine Controls .
• Inspect the powertrain control module (PCM) grounds for being clean, tight, and in the proper locations. Refer to Power and Grounding Component Views and Engine Controls Schematics .
• Search for bulletins.
• Verify that the driver is using the correct starting procedure as described in the owners manual.

Sensor/System

• Inspect for an engine coolant temperature (ECT) sensor that has shifted in value . Refer to Temperature Versus Resistance .
• Inspect for a skewed manifold absolute pressure (MAP) sensor . Refer to Altitude Versus Barometric Pressure .

Fuel System

• Verify there is adequate fuel.
• Inspect the fuel pump operation. The fuel pump should turn ON for 2 seconds when you turn ON the ignition. Refer to Fuel Pump Electrical Circuit Diagnosis .
• A faulty in-tank fuel pump check valve allows the fuel in the lines to drain back to the tank after the engine stops. Refer to Fuel System Diagnosis .
• Test the fuel injectors. Refer to Fuel Injector Diagnosis .
• Inspect for incorrect fuel pressure. Refer to Fuel System Diagnosis .
• Inspect for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

Ignition System

• In order to properly inspect the spark plugs or to correct a condition, refer to the following procedures:
- Ignition System Specifications
- Spark Plug Inspection
- Spark Plug Replacement
• Remove spark plugs and inspect for the following conditions:
- Correct heat range
- Wet plugs
- Cracks
- Wear
- Improper gap
- Burned electrodes
- Heavy deposits
- Verify that the spark plugs are of the correct type.
• Inspect for proper ignition system output. Refer to Electronic Ignition (EI) System Diagnosis .
• An improper spark plug gap will cause a driveability condition. Gap the spark plugs using a wire gage gap tool.
• Determine the cause of the fouling before replacing the spark plugs.
• Inspect for damaged or misaligned spark plug boots.
• Inspect the electronic ignition (EI ) module for proper ground connection.

Engine Mechanical

• Inspect for the following conditions:
- Excessive oil in combustion chamber or leaking valve seals--Refer to Oil Consumption Diagnosis .
- Low cylinder compression--Refer to Engine Compression Test .
- Improper valve timing.
- Combustion chambers for excessive carbon buildup--Clean the chambers using top engine cleaner. Follow the instructions on the can.
- Incorrect basic engine parts--Inspect the following components:
• The camshaft--Refer to Camshaft Cleaning and Inspection .
• The cylinder heads--Refer to Cylinder Head Cleaning and Inspection .
• The pistons, etc.--Refer to Piston, Connecting Rod, and Bearings Cleaning and Inspection .
• Inspect for excessive crankshaft endplay that will cause the crankshaft position (CKP) sensor reluctor wheel to move out of alignment with the CKP sensor. Refer to Crankshaft and Bearings Cleaning and Inspection . This could result in any of the following conditions:
- A no start
- A start and stall
- Erratic performance

Additional

• Inspect for a restricted exhaust. Refer to Restricted Exhaust .
• Inspect the air intake ducts for being collapsed, damaged, loose, improperly installed, or leaking.
Document ID# 1853611
2006 Chevrolet Cobalt

Here's another one

Document ID# 2021349
2006 Chevrolet Cobalt

Subject: Long Crank Engine Will Not Start - keywords 2.0L 2.2L 2.4L B3060 block DTC fuel fuse extended hard key L61 LE5 LSJ low pressure pump relay stall theft UBEC wiring #PIC4110C - (09/28/2007)

Models: 2006-2008 Chevrolet Cobalt
2006-2008 Chevrolet HHR
2007-2008 Pontiac G5
2007-2008 Pontiac Solstice
2007-2008 Saturn Sky


This PI was superseded to update model years. Please discard PIC4110B.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

A customer may occasionally encounter a NO start or extended crank condition when attempting to start the vehicle. This condition can be caused by a lack of fuel pressure.
Recommendation/Instructions:

Before deep diving into the diagnostics, please check for a possible loose terminal at the Underhood Bussed Electrical Center (UBEC) for the fuel pump power supply. TAC has received reports that the terminal for circuit 120 (Gry) has been loose at the UBEC. If the terminal is backed out of the connector, replace the connector (the terminal lock is damaged and the terminal will not lock in place).

Inspect the corresponding male terminal on the UBEC. If there is a bent pin it is easy to straighten, using a business card (as a straight edge) and using needle nose pliers, straighten the pin. Then use the business card again to check pin alignment. All the pins should now be aligned together. If you find the male terminal "twisted" then replace the UBEC.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

Thanks, but I already checked for TSBs and looked over both of those yesterday at work. I just didn't have time to actually inspect as per the bulletins.

 

Any progress? My car ran like a champ Monday evening after work, now this morning it started ran for a few seconds, then shut off and now won't start.

 

I finally remembered to bring a Tech 2 home so we'll see what happens in the morning.

 

Well my car wouldn't start at at all yesterday, tried it all day long.

SAME thing this morning. After work still wouldn't start, so I began tinkering under the hood. Just checking sensor connections, looking for anything wrong. Then I began to look at the relays and fuses. Pulled the Fuel Pump relay and it was quite loose, compared to the Aftercooler and A/C Clutch, all use the same type of relay. So I checked the fuel pump relay and fuse, seemed fine other than looseness. Tried starting it and it fired right up!!!???

So I bent the prongs out a little to hold the relay in more snug. Probably not the problem at all, but for some reason it fired right up. NOTE: Today is much warmer than yesterday, but car still wouldn't start after work today. Took me some wiggling or whatever for it to start? It just runs when it wants to, it aint funny. When it does, it runs absolutely perfect! Get that?

 

Well wouldn't you know my car started fine this morning, granted it was about 30* vs. the 15*-20* we've been havin. I brought home the Tech 2 again so hopefully it acts up tomorrow. I also got a chance to check out the heated seats today which weren't working, found a blown fuse, replaced the fuse, driver's seat still doesn't heat, just my luck. I also ordered a new center bezel/plate the other day due to peeling paint, well the new one arrived and it's already doing the same thing, go figure. Guess I'll just paint one myelf once it warms up.

 

Cars been running and starting great, I'll keep you posted on when it acts up again.

I'm sure it won't be long, I think it might be when it gets really cold, like you said.

 

my ss/sc does this... or done it before i stored it, sometimes when it would start i would see HUGE ammounts of black smoke, and when i would try to rev it, it would bog.