HELP....Any auto mechanics here ?

[RTR]

I have a 2002 Silverado 1/2 ton ,1500, 4x4, Z71 pick-up, w/140,000 miles that I've owned for 10 years.Its a 325 V8 all stock factory eng.The problem started During the last cold snap .....Once the outside air temp drops below freezing it starts up(like normal) w/o problems.But then,for the 1st 15 seconds it climbs to 2000 rpm.Then it will bog down(wanting to stall)...After about 90 seconds of driving its purring like a kitten.....BUT WHEN the outside air temp is above 40 degrees there is no problem at all w/start-up & or running..Truck has been well maintained.And I run dry gas in it. ...Thanks for your time.

 

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[RW]

Mass Air Flow Sensor maybe?

 

[RTR]

Mass Air Flow Sensor maybe?

Could be .I think it was changed about 7-8 years ago......thanks

 

[Limitool]

No lights on dash right...? Obviously?. Do you or have you ran a fuel injector cleaner through your gas tank. Rising to 2000 rpm's may as RW said just an air flow sensor...? That would do it. Kind of like the old style choke sticking.

 

[choppadude]

I believe it is the "Hot wire" Style MAF sensor, try some MAF cleaner on it and see if it gets better. If not the wire itself may have a break in it. A good shop can hook up a scan tool with live data and figure it out pretty quickly.

 

[relic nut]

Don't know if you have a Auto zone nearby, but here were I live they will hook a code reader to it for free. Might tell you if it's a sensor.

 

[RTR]

No lights on dash right...? Obviously?. Do you or have you ran a fuel injector cleaner through your gas tank. Rising to 2000 rpm's may as RW said just an air flow sensor...? That would do it. Kind of like the old style choke sticking.

Thanks........Yeah,during last summer I ran 'fuel injector cleaner' through it.

 

[RTR]

Thanks guys for the help.Tomorrow is going to be warmer.I'll try all the above & see what happens.

 

[Limitool]

Don't know if you have a Auto zone nearby, but here were I live they will hook a code reader to it for free. Might tell you if it's a sensor.

That's why I asked about any "lights". But even without an indicator maybe a code will pop up... hell I don't really know.

 

[mick56]

Most of the auto stores around here will check for any codes for free. Thats the first place to start. You don't want to start just changing any parts.

 

[toddbbq]

Parts changing and a "no" electronic part return policy can and will get expensive pretty quick

 

[AlienLifeForm]

OBD II Scanners are so cheap anymore, every vehicle owner should have one. It does sound like a MAF or IAC issue though.

 

[huntsman53]

Mass Air Flow Sensor maybe?

That is a very good tip and possibility. A good cleaning of the MAF is likely in order. Also, it would be best to clean the Throttle Body while you are doing maintenance on the truck.

 

[huntsman53]

Thanks........Yeah,during last summer I ran 'fuel injector cleaner' through it.

Probably time to do a repeat and add some Fuel System Water Remover as you may have gotten some water in the gas tank and/or fuel lines due to condensation when transitioning from hot/warm to cool/cold temps.

 

[trdking]

The MAF should throw the check engine light though? Is their any kind of preheater on the truck? It may not be warming the fuel at low temps. I do know that many sensors can cause this problem especially the MAP and TPS also MAF as said above but until it throws a code it will be very difficult to diagnose. I have this very same truck BTW it is Awesome!

 

[The Recovery Agents]

Sounds like your truck is inhaling air on the wrong side of the mas air flow senser untill that part swells up with engine heat. Such as intake manifold gaskets or loose air tube clamps . As others have said check for history diagnostic codes with scanner. I would have my trusted mechanic give it a smoke test to check for air leaks. I just had one that the intake gaskets were doing what you describe, especialy with the tempature . The way i found it was smoke test. Had another with same simptoms as you describe and it was egr tube pin holes rusted in it, again i found it with smoke machine. Just my thoughts good luck.

 

[FreeBirdTim]

Intake manifold gaskets. Exact same vehicle, which is not a coincidence.

https://www.2carpros.com/questions/chevrolet-silverado-2002-chevy-silverado-rough-and-uneven-idle-on-cold-morning

 

[civil_war22]

I’m a ase certified diesel mechanic and for what this holds I’ve seen on gas engines in the cold the maf can act up and also a cracked manifold or even broken vacuum line

 

[RTR]

I’m a ase certified diesel mechanic and for what this holds I’ve seen on gas engines in the cold the maf can act up and also a cracked manifold or even broken vacuum line

Thanks .Cracked manifold ? Lets hope not

 

[civil_war22]

Have you used anything to check for vacuum leaks around the engine bay? I would suggest doing that to see if that may be the culprit