detonation

[camarossguy2]

First post here!

Just bought a 89 k5 blazer

Noticed on the drive home a small "studder" figured it was some minor ignition thing.
Well i did"
Cap/rotor
plugs
wires
fuel filter
air filter
And noticed the pluges being very vry white and some showed signs of detonation

I figured maybe the fuel filter may have been blocking some flow and causeing it to run lean

Well driving it now it continues to detonate. ushally happens cuisin on the freeway at about 70 when i start going up an incline

I tried sea foaming the intake and runner to clean out as much carbon as i could and still does it. both injectors visually look to be spraying fine.


What could be causing this?
Engine temp is about 185 all the time.
Im trying a tank of premium and seeing if that helps but i dont think it will. as far as i know the its 100% stock



Im very very mechanically inclined and have a vast knowledge of cars, especailly the lt1/ls1. Gunna take a while i guess before im used to this older stuff



Lastly, what other forums are you there for these cars? preferably FREE ones. Yall should check out camaroz28.com 50,000+ members. free, paid for by advertisers of course, that site is bankng, and becuases its doesn't scare people off with a ridiculous fee, there are so many people and post you can find an answer to any questiong you could ever have.
Please dont take this as a negative comment, but more of a sugjestion to benifit you all, including the admisitrators.

THANKS

 

[txfiremank5]

I believe the knock sensor is supposed to control detonation. If it's doing it, maybe it's bad? I would think you would get a code though... It's usually the connection that goes bad and not the sensor, maybe it's come loose? /forums/images/graemlins/dunno.gif Worth a look I guess.

 

[pauly383]

I can think of three good reasons in an otherwise good truck , which is supposed to have a way of retarding automatically .

1. Bad valves . I had a lot of ping the day I bought my truck . New heads fixed that .

2. Gears way to high . It is known that lugging an engine will produce ping , just like trying to leave a stoplight in high gear in a stickshift truck . If you have highway gears and that overdrive it may ping tipping it in to accelerate . Worse on hotter days too .

3. Trans not adjusted right . That thing should kicjdown to third in that situation , maybe second on really steep grades , as soon as you give it more gas .

Hope it gives you some ideas where to look . Maybe just run better gas /forums/images/graemlins/dunno.gif

 

[camarossguy2]

Thanks guys, i will look into that