I figured I could bang this here because my truck is the old body style and evidently a step-child because nobody actually has a page for the 97 HD, but is the same as the 96.

Anyway, I have Spark Knock at Wide Open Throttle. The truck has 178k miles but runs GREAT. There are no codes just had them checked yesterday. I had the CAT removed because someone said if its pluged, it could cause it. The EGR, EVP,EVR, all check good, the EGR is clear no clogs. The base timing is set at 10* with the SPOUT off. I have run SEAFOAM through it. All the Emmissions are in tact, I even replaced the 02 Sensor. Anyone else had this experience and what did you do to fix the problem. I even tried Super Unleaded. The timing seams to be advancing to far but with this being computer controlled,I dont know how to limit it

This truck runs great and I dont wanna burn a valve or piston with this thing pinging like that.

 

what octane fuel are you runing? how much ethenal?

have you tried running higher octane to see if that helps the problem?

 

Yes but I that was before I fixed my EGR. I need to try the 93 Super again, But this truck should run normal on 87, that is what it was designed for. Actuall I think I only tried the 91.

 

how much ethanol is used in your area?

if the truck ran fine in the summer maybe the winter blend fuel is causing your issue, try the 93 and see if it fixes the issue

 

I dont think there is different blend fuels here in Texas, it does not get very cold down here

 

so I'm guessing that you didn't try the higher octane?????

 

I tried the 91 a few months ago, but didnt do much. I added a can of seafoam to gas, I am going to run that out. I did the seafoam the other way and didnt make a difference. I just set the timing to 8* and when I run this tank 1/2 tank with a whole can of seafoam, I am going to fill it with 93 ( SUPER ) and see what that does. I ran the codes and got a 111 / system pass. So I am thinking maybe a injector flush or maybe a set of new injectors. The truck has 180,000 miles on it. Runs great just the clattering problem

 

The 93 octane took care of almost all theSpark Knock. There is a little there but probably because I hace the timing set a about 14* right now. I am probably gonna set it back to 10*

 

Well I know I have not posted in a awhile but , the Spark Knock is still here. I have been through the whole truck looking for vacuum leaks and such. Still NO codes and the timing is set at 10*

 

Hey Jeff, haven't heard from you for a while. About 500+ posts ago & a different Forum! Damn, still haven't licked the ping prob? If I remember your 02's are relatively new & your Sensors are reading just within range so as to duck code setting and was your truck an ethanolic? What plugs are you running? If your running 2x plats, I'd suggest running stock Motorctaft copper cores. They are designed to go before causing damage to the engine so they're a good idea from a safety standpoint. They also run cooler so you might actually be able to bump your timing up again with them, minus the ping. Who cares if you have to change them sooner, I like to see my plugs more than once every 50K miles anyway. Also, get yourself a can of MAF cleaner (or Elecrtonic contact cleaner) and douche your MAF sensor (don't make physical contact w/ the sensor wires/ you can get tamper proof screw drivers at any parts store) & the o2 sensors (Ethenol is not their friend) . You already replaced the EGR regulator before the EGR valve didn't you? On OBD1's after many out of range outputs by a sensor, the ECU locks out that sensor and substitutes a generic amount. Changeing the sensor sometimes doesn't alleviate the problem as the EMC stores the sensor lockout in the KAM (kept Adaptive Memory). Clearing & rebuilding the KAM takes care of this w/ OBD1's. I don't know what the drill is for OBD2's. Your's is an OBD2 w/ MAF, right? Going down a step on your themostat (195F to a 180F) is usually helpful, but I think you already did that didn't you?

 

shouldnt be, i would disagree with the theremostat. its made to run 195, not 180.

read the plugs, are they white? what is the fuel pressure?

 

Man thanks ALOT for yalls reply, they wont answer my questions on the other forum.

Anyway, I may have found my problem, mostly someone had messed with the throttle stop screw or idle screw , whatever its called nowadays. I set the idle and it fixed the sluggishness of the truck, runs alot better, I gues it was causing the TPS to read wrong.
anyway, almost all Spark Knock is gone. I think I may have found the reast of the problem, I think My EGR Valve itself is bad, I have not changed it because it seamed as thought it was working, but I noticed something the other day. It makes a noise, kinda of like a fluttering noise or rattle when I rev the engine and the happens when the idle comes back down. I can see the EGR diaphram move up when I rev the engine and when it goes back to idle, I can actually see and hear the flutter/rattle.

I also need to replace my water pump, its leaking from the nottom, I found that the other day also

 

good to hear you're getting 'er worked out

 

Do yall think the sound I am hearing from the EGR is right or wrong. I will replace it, I just dont want to throw money at it

 

An EGR Valve Diaphragm ruptured could make that noise & would also cause your ping.