kyleiscool

I have a 2000 silverado 4.8 ex. cab with 134,000 mi. actually my dads truck but im trying to help him with it. its completely stock. I have done every typical maint. to it required by dealer. the past few months when I would go to start it while its warm it would take almost 5 sec. to start then once it would start it would have a rough ilde for a few seconds and sometimes die or it would start to run fine. When its cold it will fire right up with no issues. It will run fine once its started and i have no power loss or any other differnces while driving. Ive tried to put the ignition on run for a min thinkiing the fuel pump wasnt pushing fuel quick enough before i would start, but no help. I have heard it was the mass air flow sensor, so i replaced that with a new one. that didnt change. Im thinking it might be the 02 sensors, but not positive. the check engine light isnt on and i have read it with the o.b. scanner and it came up clear. any help would be much appreciated. thanks

MDTAHOE

Without seeing the data and performing other test it will be hard to help you but I can assure you of one thing O2 sensors are NOT causing your problem. They have NO effect until it is running

Koffietje

plugs?


(I love this kind of recommendations. Like trying to help someone out in one single word. It says so much and really nothing at all, doesnt it?)

Have you tried using "The Force"? (Wave hand over engine, wispering "Start up" )


No, just kidding. The force doesnt work. (Took me 2 years to figure that out, but then again, I saw Star Wars, when i was 8 years old. And one day, i stood in front of a shop, waved my hands towards the door and it opened automatically. It gave me high hopes).

Yes, I'm drunk. But that still doesnt mean you cant check your plugs, does it? I think your plugs arent suitable for the amount of heat your car generates, which makes it hard for the plugs to ignite while the engine is warm. Its just a thought.

kyleiscool

The plugs have about 3,000 miles on them. I got the exact same plugs that came out of them. i believe ac delco is the brand. the gap is correct also. i checked that too. ya i wish i had the force for alot of things. especially women.. ha jk. thanks though ill keep trying.

suzuki-guy

Have you checked the fuel filter???

kyleiscool

Yes the in line fuel filter is good. its been recently replaced.

lukemoore646

check the fuel pressure when it does this, and the spark, one of the two is the problem, its the long road of diagnostics

Koffietje

I'm starting to think that a television show in the good old sense of "House M.D." for cars would have a lot of viewers.
(House M.D. : television serie with a crazy doctor who has to diagnose uncommon illnesses from a bunch of freaky patients. Or are they just american? )

Would be nice to finally have a television serie that would end with the phrase : "It turned out a small kitten had crawled all the way in the exhaust pipe and was burned up there." Man that would make great television.

I would just like to add this : Whenever anyone says "I have rough idle" , i always automatically answer : did you check your PCV valve?

I know it should have the same issue with a cold engine, if its the pcv, but still, no harm in checking it out, is there?

ukrkoz

i do not drink, so here's a very sober - and very good - suggestion:

READ THE CODES!!!!!!!! don't have to be a jedy to do this.

btw, bad hot starts are normally sign of timing being too advanced. i know, it's electronically controlled. i know... things stretch, slip, bend, etc....

suzuki-guy

PCV valve is very easy to check if you can here a rattle when you shake it its good!