cant get rid of it, no matter what i do. its worrying me because i am about to swap in a high comp. lsvtec and i dont want it to let go due to this issue.

currently running a stock b20b with i/h/e. it has a b18b intake manifold/dist/tb and intake cam.

ive tried the following.

new dist cap, rotor, wires
stock ls ecu
neptune street tuned ecu using ls base code
different fp regulators with varying pressures including oem regulator
different injectors 2 sets of oem and rc 310s.
5,6 and 7 heat range ngk plugs with various gaps
all grades of pump octane. i have to run 93 to even come close to helping
base timing set at 16 degrees through the neptune lock ignition feature and my timing gun.

ive tried both advancing and retarding ignition timing by up to 5 degrees. it liked more timing retard. i currently have the color change on the ground strap at the bend

ive tried varying the afr in all parts of the map from mid 15s down to 13 and into the mid 12s wot. it liked it richer. when i say "it liked" that just means the plugs had the least amount of white/silver specs.

i even tried both loose and tight valve lash it didnt make a difference.

i have a new plx wideband so its accurate, as well as a new greddy egt in the 3rd runner about 1.5" from the head. the egt does get up to around 720 c or like 1300 something f while cruising. transmission is a gsr with ls 5th.


very frustrated here. been fighting this ever since i dropped the motor in last fall. ive since lost about 10 psi compression per cylinder.

 

When the car is knocking dont advance your timing never ever!
i would like to know more about the knock that happens does it happen when in LOAD?(WOT) or during light cruise?

 

happens at all times besides idle.

the car is lightly detonating (not audibly) with the timing mark where it should be on the ground strap. wtf

 

how exactly are you monitoring the knocking condition?

 

starting with a new set of plugs (i must have spent 200 dollars on plugs in the last few months), i turn the engine off at various rpm and load conditions, pull off the road and look at spark plugs. there are white and silver specs on the porcelain and ground strap. no bueno


i borrowed a friends timing light today to just make sure mine isnt bad and everything checked out good. base timing set at 16 degrees as per both timing lights and my neptune settings/logs.


there is my current timing map. its honestly not far off from the timing settings that i ran on my old 11.5:1 compression b20 a few years ago. that motor was fine and dyno tuned no detonation

 

its pre-ignition for sure! have a compression test done! see if the result is too high! this could possibly be a hotspot in the cylinder that is causing the pre-ignition

 

Was about to suggest the same thing. There has to be a hot spot in the chamber causing pre-ignition

 

All plugs hve the speckles, not just one of the cylinders.

Compression is 188,188,180,188. All leakdowns are 10% except for cyl 3 which is around 35%. I can hear it through the exhaust valves. This is the low compression b20b. For what its worth when I first got the motor in sept compression was around 195.

Could it be related to spark plug gap at all? i am currently using the 7's gapped at .040"

 

clearly you still have too much ignition advance. reduce everything other than idle by 10* and start your tuning process over. use a det can or knock ears to identify exactly when detonation occurs, and use a graphing utility when making ignition changes.

 

if i have to retard my timing 10 degrees from the factory setting for the motor to run properly there is most certainly something wrong. also, if it were an issue with this specific engine itself then id venture to say that it would have blown up long ago in the crv it came from and not made the 104,000 miles it had on it.

i do understand the tuning thought process though. truth is that i did that too, and for the plugs to be clean there was so much timing removed the car would jerk and studder a bit under acceleration

could something be wrong with my dist. and not code?

 

yes....what is the history of the distributor?

 

Came off the motor in my friends wifes integra. Car ran fine had bout 215k when the crank pulley bolt backed out and it was swapped out

 

Make sure you jumper the ECU before setting your distributor. And check where base timing in your map actually is vs. where it's supposed to be.

 

base timing set using neptune lock ignition feature. verified by actual ignition in my data tables as well as with 2 different timing lights

 

I've seen carbon debris in the distributor cap cause some pretty consistent preignition, as well as a faulty rotor. additionally, if one of the crank sensors is worn or a spindle is loose or partially broken, you can definitely expect a consistent ignition problem.
you should post a clear picture of your spark plugs for reference.

 

a more clear picture is not likely. my phone camera wont focus on anything up close anymore. you can rest assured though that there are silver and white fuzzy speckles on the ground strap, electrode and porcelain.

i have another distributor but it is a different obd so i have to find some time to rewire the plugs. might not happen for a week or 2, im knockin on the door of a 10 second pass in my other civic and that has my free time tied up currently

 

Any reason that you might have very high IAT's? Do you have the air filter right at the throttle body or anything (like a super short RAM)? That will require you to either add a teeny bit more fuel (to cool off the charge) or back off a little ignition timing (or both) to prevent some detonation.

Clearly, a mostly stock motor should operate PRETTY normal with a stock set of maps. But you never know. Maybe just backing off 5* everywhere could help.

But the strange problems you were reporting when you back off 10 deg timing don't seem normal. Normally, the car will just have less power, and studder a *little* bit (maybe) at low RPM. Not be a huge thing. Just a bunch of power and fuel efficiency gone. Should drive mostly normal. I'd worry about that distributor, at that point.

You already seem to know enough about tuning and what's going on (as well as your other cars) that I'm guessing you already know all of this anyway. Just trying to help.

Good luck
-Paul

 

combustion chamber is definitely hot, try a colder thermostat and check your fuel pressure at the rail during acceleration, verify you don't have a vacuum leak.
lastly, make sure your wideband is properly calibrated and the ground is isolated. I've had a few guys with knock problems that were tuning on skewed voltage, turned out they were just too lean.

 

finally got around to swapping distributors today. all the wires had the sheathing frayed and ripped where they go through that rubber grommet on their way into the distributor itself. cant say for sure that was my main problem but i know it wasnt good.

anyway, with the new dist i was able to put back 2-4 degrees timing into the map. egt's are back down to something more normal, throttle response is good and plugs looked clean after about 30 miles. thats even with a set of zfr5e's. fingers crossed, ill check again in a few days and be back with a good or bad update.

 

blah, white fuzzy specks on my plugs again. weird it took 2 days of driving for them to show up. anyway, the 7's went back in, and im fixing to redline it till it blows

 

Why not get it on a dyno?

 

Add some methyl hydrate to your fuel. 2l meth to 25l gas. See if that cures the knock

 

Honestly I dont really care that much about this motor. Lsvtec is on the stand ready to go in. That I do care about though and want to make sure the issue is not something related to the chassis that will continue after I swap it.

Talking to a frriend yesterday I kinda have a new theory. Bad valveseals contaminating the combustion chamber with some oil. Would kinda explain why nothing I do is making a difference

 

The plugs def don't look right but then again anytime I have seen detonation it never shows up on the plug like conventional theory supports. The fuel pressure and tuning afr's responding correctly should essentially rule out anything fuel system related. Have you tried just running the stock ecu? This is how I usually run my b20 swaps, stock ls ecu with a bump in fuel pressure, thats actually my dd right now. Egt seems normal too, strange.

 

OMG what the hell did u do to your map. You only have two columns for boost, which means from 0.5 psi to 11 psi your ecu has to Interpolate the ignition and fuel parameters. No wonder why you are detonating