Why has it lost power?

[airtight_python]

I drive a 2002 Silverado regular cab with the 4.3L. I keep it maintained... change the oil every 3k miles (even switched to Mobil 1 Syn). I put a fresh air filter in about as often as I change the oil. Also changed the fuel filter recently. Run injector cleaner often. Today I ran some Sea Foam through using the brake booster vacuum method. I did notice a little power increase after that but not what I expected. It feels like the truck has lost ~20 RWHP since I got it with 19K on it, now has 37K. The next thing I can think of is to change the plugs. I have a feeling it won't change anything though. What would you look for after that?

[jumpingjack66]

i would just regap the plugs. little to soon to change them..JJ

[airtight_python]

Thanks for the quick reply JJ. I guess the reason for that would be that buildup on the plugs could change the gap? Might just need a cleaning. Any more ideas anyone?

[jumpingjack66]

gap would change as metal disapated from electric discharge will be slight but can make a small difference. My truck seem to have lost a, little step here lately and i havent checked my plugs either but i would guess thats part of the prob at 60,000 plus miles. Everything else your doing sounds appropriate . I do run a double dose of injectore cleaner with a tank of 93 octain gas about every three or four months and that seems to perk it up.. jj

[airtight_python]

Someone else has got to have some more ideas?

[jeverett]

Buy a new engine like me lol. Just kidding, I'd check the air filter and the fuel filter again. I once had to change mine 3 times to get some crap from a bad tank out of it.

[sc_customs]

throw in a 4.8

[jeverett]

Sheeeit, I had a blown 5.3 I woulda given you lol.

[yankeeintruder]

You might try some Red Line Complete Fuel System Cleaner.......... seemed to work for me as it really perked my Silvy up!! One bottle treats 100 gallons but you use a whole bottle first time and then an ounce or so each tank full after that......... although I haven't been doing that way.
I just use an entire bottle every 10-12 tank fulls. Guess I'm gettin' lazy in my old age.

[tidalcock]

Please let us know how the STS works out. I posted an inquiry about it two months ago and got no responses.

[sc_customs]

I probably won't get it installed until next year...it's not exactly smog legal here in CA yet, so I have to wait until after December to install it, which is when I gotta smog.

So pretty much December 1st my day will go something like this:
8am - Smog check......9am - Install turbo

[jeverett]

Wanna read onthe STS, go to www.LS1TRUCK.com THe dude who's tuning my truck installed one on his 94 and has raved about it.

[sc_customs]

jeverett,

keep us posted on that nelson tune. i was readin up on it and it sounds pretty tempting. I kinda need a new PCM anyway cuz the one I got now is out of a suburban

[jeverett]

Allen called me yesterday, but I was still tweaking another system I put in a Duramax, soo..I didn't get to talk to him. I'm about to explode waiting on it.