New guy says hi and I got some questions

[Burb fan]

Hi everyone. I got a 98 suburban, 4x4, 350, 1500. I have noticed that when the engine is cold (and or cold outside) it has a good bit more power than when it is warm. I guesstimate 20-30 hp. Anyone know how I could fix that? I am guessing it is a sensor issue. I had a 93 Jimmy with a 4.3 which would do the same thing. Also the sububan doesn't like to start like it used to. The cold problem was always there, the start issue is new. I also have the thump problem which I guess maybe I will try and fight a dealer with. Any thoughts on any of these would surely be appreciated Thx.

[mrjohnwayne]

rule of thumb. The cooler a motor runs the more power it will produce. There is nothing wrong with it.

[Moostang]

JohnWayne has it.. that is why I used to ice my intake down at the races. As far as your other issues, we need a little more info.

[bradrhale]

what do you mean not start like used to??

[chevyguy]

Sou8nds like time for a general tune up to me.

[Burb fan]

thanks for quick response sorry it took me so long to get back. On the cold problem I agree with you guys about cold engines produce more power, but it just seems like too much more power when cold, All of my previous trucks that had a carb on them wouldn't do that and somewhere that i read that when a certain sensor (maybe O2) gets hot, it produces the wrong reading. Any thoughts on that would be great. As to the starting issue i guess i will throw some plugs at it and see what that does. i looked at them about 7000 miles ago and they looked nice. I did do a cap and rotor at that time. You guys have any good suggestions for plugs? Some swear to keep to keep the ACs but I am open. Those Bosch look good.

[gmctrucks]

My truck had the same trump what the dealer did is repack the tail part of trans with some new heavy duty grease it felt like when I came to a stop light like if someone hit me behind. Let us know what's going on and if this has helped you it has fooled many of people before?

[bradrhale]

i would look at the plugs before i went blowing money on new plugs that i really didnt need. any sensor going out will make your truck run different. if its overfueling all the time, i would think that it could be an o2 sensor. you have to remember too, this is EFI not a carb. big difference in fuel delieverance. try not to compare it with a naturally aspirated engine in the way it runs.