Knock Retard

[dgoodhue]

Another year same problems :rant: , nothing I do seems to help my long term knock retard.

I am getting a bunch of it (usually 14-16 degree by the top of first) with my T1-16 programming. Today from 0-70mph I had 16.4 KR and its 67 degrees out. Under part thottle I have no knock retard. On some of my track runs, I got a tons KR in 1st but it takes so long to ramp out, I don't get any additional KR until the top of 3rd.

I am running 93 octane and I have done a bunch of stuff to try to remedy it. It is NOT false, I tried reloacting the knock sensor with the same result (the knock comes in the beginning of 2nd gear instead of top of first) and race gas does help. I don't any have ignition flutter at all. My truck finally idles very good. I use diacom and have some files.

This is what my truck has (I am sure I will forget some things)

-Conrad Cap and Rotor, UR6 gapped at 0.030, MSD 8.5 mm Wires All replace 1200 miles ago. (could the small gap affect this negatively?)
-TEC Cleaner (twice, last time 400 miles ago)
-New A/C Delco Coil
-MSD 6AL (tested with and without)
-4K miles O2 sensor.
-Redid all the intake, TB gaskets and cleanout out the intake.
-1.6RR's I know the adjustment is right, I re-did it with the engine running.
-Tried swapping ECM's, same result
-Have higher output alternator same result.
-IC pump works, Soft lines, IC temps usually start off at around 110 degrees.
-Radiator temps around 160-165
-Doesn't overboost, does have Random Tech Cat.
-New knock sensor.
-I have a 255L walbro, the fuel pressure is set at 45psi (My BLM's are at 128) The FP gauge say the fuel pressure is holding properly and tracking under boost. More FP doesn't help, it just make my truck run rich at idle.
-Checked balancer with piston stop.
-professionally clean the injectors and had them flowed.
-RMI cooling systems cleaner, bunch of junk is in the coolant can, but no real help.

In the past, I have tried retarding the timing 1 degree or 2 it doesn't reallyhelp. (it helps by a degree or two.)

The truck was 100% stock and untouch when I bought it. It has 49K miles on it, never been driven in snow and the previous owner claims it was never driven in the rain, (though that has changed), so its very clean and I am not dealing with rust.

I am really kind of lost on what may or may not help remedy this situation.

The only thing I want to try is cleaning the ground on the back of the cylinder heads. I have a new ignition module that I haven't replaced yet, but I am not sure either of those are going to bring my Knock retard down 10-12 degrees. I have a WBo2, and but haven't hooked it up yet. It is my next project. I am just really lost on what to try next.

 

[93ty475]

Re: Knock Retard

I tried reloacting the knock sensor with the same result

Where'd you put it? Front of lower intake?

 

[SeattleSy#1255]

Re: Knock Retard

Another year same problems :rant: , nothing I do seems to help my long term knock retard.

I am getting a bunch of it (usually 14-16 degree by the top of first) with my T1-16 programming. Today from 0-70mph I had 16.4 KR and its 67 degrees out. Under part thottle I have no knock retard. On some of my track runs, I got a tons KR in 1st but it takes so long to ramp out, I don't get any additional KR until the top of 3rd.

I am running 93 octane and I have done a bunch of stuff to try to remedy it. It is NOT false, I tried reloacting the knock sensor with the same result (the knock comes in the beginning of 2nd gear instead of top of first) and race gas does help. I don't any have ignition flutter at all. My truck finally idles very good. I use diacom and have some files.

This is what my truck has (I am sure I will forget some things)

-Conrad Cap and Rotor, UR6 gapped at 0.030, MSD 8.5 mm Wires All replace 1200 miles ago. (could the small gap affect this negatively?)
-TEC Cleaner (twice, last time 400 miles ago)
-New A/C Delco Coil
-MSD 6AL (tested with and without)
-4K miles O2 sensor.
-Redid all the intake, TB gaskets and cleanout out the intake.
-1.6RR's I know the adjustment is right, I re-did it with the engine running.
-Tried swapping ECM's, same result
-Have higher output alternator same result.
-IC pump works, Soft lines, IC temps usually start off at around 110 degrees.
-Radiator temps around 160-165
-Doesn't overboost, does have Random Tech Cat.
-New knock sensor.
-I have a 255L walbro, the fuel pressure is set at 45psi (My BLM's are at 128) The FP gauge say the fuel pressure is holding properly and tracking under boost. More FP doesn't help, it just make my truck run rich at idle.
-Checked balancer with piston stop.
-professionally clean the injectors and had them flowed.
-RMI cooling systems cleaner, bunch of junk is in the coolant can, but no real help.

In the past, I have tried retarding the timing 1 degree or 2 it doesn't reallyhelp. (it helps by a degree or two.)

The truck was 100% stock and untouch when I bought it. It has 49K miles on it, never been driven in snow and the previous owner claims it was never driven in the rain, (though that has changed), so its very clean and I am not dealing with rust.

I am really kind of lost on what may or may not help remedy this situation.

The only thing I want to try is cleaning the ground on the back of the cylinder heads. I have a new ignition module that I haven't replaced yet, but I am not sure either of those are going to bring my Knock retard down 10-12 degrees. I have a WBo2, and but haven't hooked it up yet. It is my next project. I am just really lost on what to try next.

Well Dave I feel you pain...what does it do with the stock chip in it? Any major differences? 16* you should probably hear it pinging i'd guess, do you hear it? Is your IC pump working? what about timing? When you pull your plugs do any of them look way different than the others...just trying to narrow down the cylinder(s) perhaps?

also, how difficult is it to relocate the knock sensor? I know wher epeople are putting them, but how is it wired going from the back of the block to the front of lower intake? (not trying to hijack your thread)

 

[Don W.]

Re: Knock Retard

I suggest that you pull all the plugs and take a look. Post a photo and we can chime in.

FYI I’m running 100 race gas to get rid of mine.$$

Interestingly, based on a confirmed plug read by an expert, I have a lean condition on the driver’s side only.

Since I'm doing a AFPR anyway, my next "repair" may be to pull the entire fuel rail and look for restrictions. News at 11:00.

 

[NecroWolf]

Re: Knock Retard

carbon build up?

 

[SeattleSy#1255]

Re: Knock Retard

carbon build up?

not likely since he ran 2 cans of TEC and cleaned out the TB and intake himself.

 

[myclone]

Re: Knock Retard

My initial vote is carbon build up even though you ran the cleaner through it.

Have you tried different CALPACs since the ESC stuff is in there (Im assuming you used the same chip even though you swapped ECMs..if not ignore this).

Has the truck had KR issues ever since youve owned it? It may be a situation that the truck has always detonated and it wasnt caught when it was shipped (dunno how well they tested each and every truck before shipment) and the previous owners didnt drive/beat it enough to blow it up from detonation. If the truck has always detonated then it may require more serious diagnosis such as degreeing the cam to make sure production tolerance stack didnt cause the cam to end up installed advanced, wrong head gaskets installed (=high CR), wrong pistons (=high CR), or some other mechanical "constant" that we take for granted is correct but on your truck it is not and slipped through the cracks of the production line/testing/QC.

How bout the distributor? Swapped it out? Even though its low milage there may be something loose or dicked up (like the reluctor ring) which could be adding advance on top of the ECM and base timing setting anywhere above idle.

Thinking out loud....

 

[dgoodhue]

Re: Knock Retard

Well Dave I feel you pain...what does it do with the stock chip in it? Any major differences? 16* you should probably hear it pinging i'd guess, do you hear it? Is your IC pump working? what about timing? When you pull your plugs do any of them look way different than the others...just trying to narrow down the cylinder(s) perhaps?

It pings with the stock chip not quite as much, but still quite noticable 8-10 degree if I remember right, I always tried to use Octance booster to test it. I haven't used the stock chip in a long while though. I heard it ping once on me with the stock chip. Maybe I should burn a stock chip with the 18 degree of retard the ultimate has (as opose to 12.6 degree stock)

IC pump works fine, timing is trying for 14 degree at WOT but that never happens... I have had a bunch of people look at my Diacom runs, everyone says it looks fine except for the KR.

My plugs all look the same. I will post some picture this week as I was going to increase the gap a little since my Alky isn't working.

also, how difficult is it to relocate the knock sensor? I know where people are putting them, but how is it wired going from the back of the block to the front of lower intake? (not trying to hijack your thread)

I did have to remove that PIA coil/map bracket to get to the connector. For the connector I just made an dextenders. I am sure you goto an auto parts store and find a knock sensor connector (to fit the new KS) and find a connector to fit the factory harness. I had a knock sensor test fixture that connected inline between the KS and ECM. I used the parts from that to connect to the factor wiring.

 

[dgoodhue]

Re: Knock Retard

I rearranded you wording so my response flowed better.

Has the truck had KR issues ever since youve owned it? It may be a situation that the truck has always detonated and it wasnt caught when it was shipped (dunno how well they tested each and every truck before shipment) and the previous owners didnt drive/beat it enough to blow it up from detonation. If the truck has always detonated then it may require more serious diagnosis such as degreeing the cam to make sure production tolerance stack didnt cause the cam to end up installed advanced, wrong head gaskets installed (=high CR), wrong pistons (=high CR), or some other mechanical "constant" that we take for granted is correct but on your truck it is not and slipped through the cracks of the production line/testing/QC.

It has had KR since I have owned it. The only thing that sticks out as being different about my truck is that it sat for a year and half and during that time the heater core let go while in storage.

I looked back at some of Diacom in the early day of owning my truck stock chip. I was getting peaks of 5-6 KR but that was with Xylene added. It was getting a lot of 2-4 KR which is a lot better than I have now.

I would guess it has the right pistons and headgaskets, but I also have a new set of heads gaskets in case I decide to pull the heads. The cam degree has definately crossed my mind. No mechanic or other owner has fooled with the motor in the truck though, every bolt has been untouched, except for the spark plugs, fluids and air filter.

My initial vote is carbon build up even though you ran the cleaner through it.

I sort of think so as well, and I haven't ruled it out. I am tempted to swap a different set of heads and clean up the pistons. This year, I was hoping maybe due the leaky heater and sitting that maybe corrosion has built up in my heads cooling ports which is causing carbon build up. That is my reasoning for RMI-25 cleaner.

Have you tried different CALPACs since the ESC stuff is in there (Im assuming you used the same chip even though you swapped ECMs..if not ignore this).

I can't remember. At the Pittsburg meet last year I swap a different chip in my truck but I can't remember if I reused my memcal or I used someone else's. I can try that.

How bout the distributor? Swapped it out? Even though its low milage there may be something loose or dicked up (like the reluctor ring) which could be adding advance on top of the ECM and base timing setting anywhere above idle.

Original distributor. Never thought about that.

I have always read about chip burning, that you do what the vehicle wants not what you think it needs. Maybe I should apply that to my Sy until I figure this all out. I am currently thinking about retarding my timing (via chip burning) and tuning it to see how much timing I need to take out for my truck to run knock free on pump gas. I noticed the current Ultimate (ver 10,11) are running less timing 11 degree WOT than the ver 7 I have been using 14 degrees. Maybe that is better starting place.

 

[leroy]

Re: Knock Retard

How are your intake temps? Sorry if I missed that.

It's hard to check the balancer with a piston stop. It can be done a lot easier with the heads off. If you have the balancer off, the zero mark should line up with the keyway. Being off a couple of degrees could really mess with your knock retard.

I would recommend rebuilding the distributor to see if that helps.

My original Syclone motor was not quite that bad, and I went through everything. Lowering the boost helped. What really helped was water injection. With water only, I was able to run 20 psi on pump gas without knock.

The easiest way to relocate the knock sensor is to buy a new pigtail and run a new wire to the ecm. You can leave the stock sensor and wiring in place.

Jim

 

[myclone]

Re: Knock Retard

I have always read about chip burning, that you do what the vehicle wants not what you think it needs. Maybe I should apply that to my Sy until I figure this all out. I am currently thinking about retarding my timing (via chip burning) and tuning it to see how much timing I need to take out for my truck to run knock free on pump gas. I noticed the current Ultimate (ver 10,11) are running less timing 11 degree WOT than the ver 7 I have been using 14 degrees. Maybe that is better starting place.

I dunno Dave... My truck when it was stock had KR in the 4-5deg range no matter what other than drowning it out with 110 octane but then again it had the wrong plugs in it, original plug wires, etc. After putting the correct parts as well as the typical syty durability upgrades (255 FP, conrad cap, etc) the KR dropped to 1-3deg which I could live with.

Anyways, what Im getting at is that IMO a few degrees KR is normal in these beasts when theyre stock or close to it but you have way too much for some reason which may take some digging to find the cause. My thinking in your situation is that burning a chip with less advance would solve your sypmtom but wouldnt address the root cause. Not that Im trying to talk you out of burning chips its more along the lines of that being a last ditch effort to fix the problem after youve exhausted everything else since by my experience you should be getting 5deg or less of KR with 93 octane.

BTW, what brand of gas are you using (and octane for that matter)? I did some testing on different brands of gas to find out which, if any, gave me less KR and found that Shell 93 octane was the best, then BP and AMCO were dead even, and EXXON was the worst. I didnt even try any of the convenience store gas since they usually buy whats left over which would seem to be a setting for inconsistant octane from batch to batch. Right now I can run 17psi on Shell 93 octane with 1-3deg of KR which as I mentioned is livable IMO.

More thinking out loud...

 

[dgoodhue]

Re: Knock Retard

How are your intake temps? Sorry if I missed that.

It's hard to check the balancer with a piston stop. It can be done a lot easier with the heads off. If you have the balancer off, the zero mark should line up with the keyway. Being off a couple of degrees could really mess with your knock retard.

I would recommend rebuilding the distributor to see if that helps.

My original Syclone motor was not quite that bad, and I went through everything. Lowering the boost helped. What really helped was water injection. With water only, I was able to run 20 psi on pump gas without knock.

Today, I tried running the timing 6 degree retarded, I had a peak of 10 degrees at the top of second gear, but it was 5-6 degree pretty early on. WTF I supose it was to be expected but I figuired if I cut the timing pretty early it might prevent the big spikes.

My intake temps are usually under 100 depending on the outside temperature. It sometimes gets up to 120degree on hotter day by the end of the 1/4 mile.

What do I need to rebuild the stock distributor? I have a new GM ignition module (not install) Is the reluctor ring like the pick up coil. I should do some research on it. Maybe I should put some real effort into getting my Alky to work.

 

[dgoodhue]

Re: Knock Retard

My thinking in your situation is that burning a chip with less advance would solve your sypmtom but wouldnt address the root cause. Not that Im trying to talk you out of burning chips its more along the lines of that being a last ditch effort to fix the problem after youve exhausted everything else since by my experience you should be getting 5deg or less of KR with 93 octane.

BTW, what brand of gas are you using (and octane for that matter)? I did some testing on different brands of gas to find out which, if any, gave me less KR and found that Shell 93 octane was the best, then BP and AMCO were dead even, and EXXON was the worst. I didnt even try any of the convenience store gas since they usually buy whats left over which would seem to be a setting for inconsistant octane from batch to batch. Right now I can run 17psi on Shell 93 octane with 1-3deg of KR which as I mentioned is livable

I am using Sunoco 93 right now. Never any no name brands, I don't have BP or Amco around here but I will try some Shell. I have used different gasolines in the past, Last year when I was at pittsburg I was using 93 BP.

I am getting really tempted to rip apart the top end look at the piston (carbon), look at my cam timing and convert my truck to Vortec, but I really wasn't planning to do this at this time or on the stock block.

 

[bezerk]

Re: Knock Retard

try to swap out those 1.6 ratio rockers.

 

[bezerk]

Re: Knock Retard

just have the feeling that some of it might be real.
do you get any knock reving the engine in neutral?

 

[dgoodhue]

Re: Knock Retard

just have the feeling that some of it might be real.
do you get any knock reving the engine in neutral?

No KR unless under WOT. No KR with 2/3 to 3/4 throttle with 10psi of boost. It does get bettre by 5 degreee or so with race gas.

 

[leroy]

Re: Knock Retard

What do I need to rebuild the stock distributor? I have a new GM ignition module (not install) Is the reluctor ring like the pick up coil. I should do some research on it. Maybe I should put some real effort into getting my Alky to work.

Just an ignition module and pickup coil are needed.

Do the plugs show signs of detonation?

Jim

 

[dgoodhue]

Re: Knock Retard

Do the plugs show signs of detonation?

I think they are tan, I can't remember if they have black specs on them. I will pull them and look tonight.

 

[KETCH-UP]

Re: Knock Retard

Dave, sorry to hear about all the knock troubles. I am surprised backing the timing out didn't help more. It looks like you have done all of the right things to troubleshoot. My TY responded well to de-carbon, and 1.5 degree less base timing when I began using the ult chip. Can you hear the knock? I am able to hear knock when I read 6 degree or so. If I push the wiring gromets thru the firewall I can hear it much better. My guess is your engine is really about 9.2 to 9.5 to 1 compression. I don't know how you could prove it. Perhaps you can rent a flexible fiber optic scope to view for carbon or non turbo pistons. I do not know if you can tell by looking at piston tops? Anyway good luck, and if you are in my area sometime you are welcome to swap any part from my truck!

 

[Syclone#1992]

Re: Knock Retard

I am having similar problems as Dave is. I have tried everything, timing is dead on zero, new plugs, wires, cap + rotor, check fuel pressure, checked everything.

When I stab the throttle, sometimes it spikes to 6 degrees for a quick sec, but goes back down. Nothing is audible though, and the truck feels strong. Stock chip is no different than a custom in most cases (only tried a mild stock chip from Hood) Race gas doesn't change it either.

I tried adjusting the injector tick, and got rid of some of it (maybe a degree or two), but still get that occasional spike when stabbing it in park.

I am out of ideas too.....is it false or what could be triggering this? What more can we do? I don't understand this because my Typhoon is the exact opposite.