Buck268

I set my timing to the factory setting of zero degrees (it said on hood sticker...). Yes, i bypassed the eloctric spark timing. Now, I am getting slight, but noticable (to me), knock, is this possible??????

I also am getting what feels like a miss somewhere.
my WHOLE ignition system is new (as of this fall, anyways...).
I also have a new ECM, but old prom (i doubt that has a whole lot to do with it though...). I am really dumbfounded, whats going on?
Edit : Forgot to mention that i get the ERG code (for got which code ## right now), but i get it often if I driver fer more that 5 miles, but mostly only when its cold out (today I drove about 15 miles with no light...). Dunno if that means anything...

Sonar_un

knock sensor bad?

Buck268

How would I check that? And also, I heard that in order to replace it - you need to drian coolant - is this true?

Sonar_un

I have no idea

JPrevost

If you're car is working like it should and you're ONLY getting the EGR error code then something isn't right with this picture. If you're at 0 base timing you shouldn't be getting knock. BTW, the ONLY way to tell if you're getting knock is to unplug the knock sensor from the harness. If it's plugged in and working then you won't be able to hear detonation because the ecm will "hear it" WAY before you do and it'll retard the timing a LOT just to get rid of it. The only way to tell if you're getting knock is to hookup your scanner software and look at knock/spark counts. Make sure your knock sensor is plugged in. If you want to replace the knock sensor then yes, drain coolant or have a pretty big catch can and be ready to get messy. It's in the block right next to the oil pan on the passenger side. Use teflon tape to make the seal with the new sensor. Always use teflon tape on coolant fittings, it's the seal proof cheap way and not as messy as that liquid teflon stuff.
I really doubt you have knock, sound to me like it's either a couple bad spark plug wires or some plugs have bad gap.

Buck268

Well, all I know is I have heard ping in my car before (or something is REALLY FUBAR). And its is very minor now (quiet is what I mean), but if I bump my timing up to say 6, or 8 degrees, it goes tick tick tick tick sorta, like marbles, I guess. How could it be a wire or plug gap??? That may make sense, cuz it feels like I may have a miss...

JPrevost

A bad spark plug wire will cause terrible drivability problems and worsen with more advance because the ecm will pull out more timing and the car will run like crap.
Check all your plug wires, if they're bad the distrib cap will have nasty arcing and the car will literally run like it's all fubar.
You really shouldn't be able to hear any detonation, you might be hearing exhaust, intake, some other crazy sounds or maybe it is detonation from a cut in the wire going to the knock sensor.

Buck268

well, what else would it be? When I bump up the timing, it gets REALLY bad, i mean, it sounds like the engine wants to turn inside out (ok, not very descriptive, but its definately a BAD BAD noise...) Sounds like pinging... maybe I dont know what I am talking about...

Silverado5.7L

I would like to add something. I have a 91 5.7L Truck.
I have the exact same problem. Brand new wires, cap, rotor, and plugs(acdelco Rapidfire pregapped) anyways could my O2 sensor or the knock sensor cause this? Those are the two I havn't changed since I bought it 2 years ago.
Thanks

Buck268

I just replaced my O2 sensor in a desprit attempt to get the gas milage ppl talk about with the 305...its been a 1/4 tank so far, and I am not seeing it...so, no, 02 sensors have nothing to do with knock

iroc22

My car is knocking really badly and it was at 0* also but I bumped it to 6* advance. My Dad's friend said that happened with his Astro and he replaced the knock sensor and it went away. So I'm gonna replace my knock sensor too when I rebuild the engine and change everything which will be soon. By the way; my car was just hooked up to a scope a week before the knocking started and apparently all the sensors were in good order. I have Taylor Spiro Pro wires and Bosch Platinum plugs. I have never been much of a fan of the Bosch plugs since day one; so those could be a suspect I guess. Hopefully all these problems will go away once the engine is overhauled.

Jza

.

Edit

Audiman

Iroc 22 is your car OBD I or OBD II. Basically if it is before 95 1/2 it will be OBD I. My stupid 1993 Suburban did the same thing. An EGR code is probably directly related to the problem, "Knock" is the production of extreme combustion temperatures usually created under load. Under Cruise though your EGR supplies exhaust gas to the combustion chambers to inhibit the flame front caused by igniting the fuel charge. The result of this is gas efficiency and lower operating temps. Make sure you EGR valve diaphragm holds vacuum, the lines are not cracked, the solenoid to activate is closing and opening properly. If the EGR is hanging open it can put nice hot air in the intake while your trying to haul some butt. Nox which is the gas that is produced during this can heat the chamber in excess of 2500 degrees causing "KNOCK". Chances are your having a problem along this line. Unless of course your distributor is worn out, your knock sensor is not properly torqued or it is bad. You can check the voltage coming out of the sensor by hooking up an oscilloscope and tapping on the housing lightly! Let me know how it goes, there is nothing that cant be fixed, just things that take a little time to figure out.

Buck268

Audiman, thanks fer the ideas! Now to find time....

iroc22

I havent got any codes at all thrown at me but it could very well be an EGR problem. I'll have to spend some time diagnosing my car's problems.

Buck268

if it was knocking @ 0*, why would you bump it UP to 6*? did the knock get worse?