ECMlink Problems with partial throttle knock

[93'colttsi]

Heres a few datalogs I took of the knock and some pulls/cruising

wondering if someone can take a look at these. Also including a copy of my basic and direct access settings

Thinking its partially phantom knock... but not so sure. Picks up the knock counts even when in neutral free-reving. If I rev it slow, no knock, but if I rev it quickly (quick stab of throttle) it gets a significant spike in knock counts. The other knock I get at partial throttle, sometimes at steady state cruise, and light acceleration. Especially if I downshift into 3rd gear while crusing on the highway and roll into it.


Running stock 2g timing tables, tried the 1g ones, tried the evo timing maps, still knocks at partial. Once it boosts and I go WOT it doesn't get much knock counts at all. mostly at partial throttle pulls... at WOT car runs around 10.6 -10.8 A/F ratio (on the wideband). I can have ecm link ignore knock below 3500rpm,and set it to ignore knock at below say 40% throttle... but I still worry that its real detonation or knock

1991 talon, stock bottom end, HTA71 turbo, FP race exh mani, FMIC, ball/spring MBC, BPR7ES @ .028", stock ignition, 1000cc PTE injectors, AEM FPR, BC 272 cams w/ adj gears BC springs/retainers, 2G MAF, ECM link v 3, EGR block off, full emission's delete, 94 octane pump, AEM meth kit v2 (disconnected for now)

Car had partial throttle knock problems before all the mods. (even when stock) Tried swapping ECU's, knock sensors, CAS, Coil packs, PT, to no avail.

4-5 degrees base timing ,no boost leaks (holds 25+ psi for quite a bit)

I thought originally it was the trans making the knock sensor go off, but when I do a quick rev in neutral, with the clutch pushed in, it still gets the knock counts (this should keep the trans input shaft from hardly turning at all, shouldn't it?) so that would eliminate the trans as causing the PK.

 

[rough]

Nice setup!

Have you tried taking timing away in those cells you are knocking in?
I don't use v3, "ecuflash user" so if you wanted to put your log into a excel file, I'll take a peek for ya!

Stock tune is known to have knock from the factory.
Pig rich knock!

Could be a bad engine/transmission mount, noisy pulley, exhaust banging something, Lifters "if you had a 7bolt"

I'm interested to see your log, usually real knock has runs!

 

[97 eclenger]

detonation could be it to. but I havent really heard of detonation at idle. at cruising speed and hard acceleration I've had happen but no reason why it was happening. hows your ignition timing?

 

[93'colttsi]

I have taken away 10 degrees of timing, knocks just the same at partial throttle, (using the global timing sliders) Added timing, knocks just the same, went from the aggressive 1g timing maps, to the evo timing map... same thing... went to the 2G timing map now. Also I don't hear any audible knocks or pining. Just the knock sensor picking it up.

Base timing is 4-5 degrees. Only this is the cams are just zero'ed out for now... didn't bother degree'ing them as they will be tuned by HP on a dyno eventually. But I had this same knock at partial throttle before even installing the cams. Also has new 3G lifters in it, have tried disconnecting the exhaust, motor mounts are still stock, no solid/poly ones yet

Almost tempted to put knock ignore settings on anything below 50% throttle and 3200 RPM and try and just ignore it.

Also should add that about 6 months ago #4 piston broke the ring lands partially off the piston. Took engine apart, replaced with used piston/rod. Re-ringed all 4 pistons, honed the cylinder walls, replaced rod/main bearings, checked the balance shaft bearings (looked OK) months after that, #1 piston broke its ring lands almost identical to before. Took engine apart, and again put another good used piston/rod in, another quick re-hone and all new rings again. Just finished the break in... put about 250 km's on it since then. Don't want to take this damn thing apart again!

 

[10's or bust]

Definitely detonation pistons prove it

 

[10's or bust]

Have you checked fuel pressure

 

[93'colttsi]

Fuel press 38 psi with FPR Line unplugged. Goes a bit lower with the vac ine connected of course, and raises 1:1 with pressure increase. (AEM adj FPR installed.)

When the knock at partial throttle occurs. The A/F raito is good. Stays stioch untill closed loop shuts off at around 0.9 load point. (aprox 3psi)

 

[97 eclenger]

pull the spark plugs out. see what they look like. if you're detonating that will tell you.

 

[93'colttsi]

Yeah, inspected the plugs (BPR7ES gapped at .028) both times I had the head off, Put fresh ones in each time as well. Plugs did not show any signs of detonation, (no melted electrodes, no splatters on porcelain or pepperin)g. as well as the pistons. only thing I noticed was the cracksin the ringlands visible from the outside of the piston, then grabbing them the ring lands just pulled right out. (also noticed the 30 psi compression on the effected hole, and the smoke coming out of the back of the car on deceleration). Did a leakdown before disassembly each time and almost 100% leakdown on the holes with the busted ringlands, all the pressure leaking into the crankcase. couldn't visually tell there was a piston problem though until I actually pulled the piston out of the block.

 

[93'colttsi]

here is some pics of the first piston that let go.

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[93'colttsi]

Well I have given up on finding the culprit, and ended up figuring its just harmonics in the engine/trans that is setting the knock sensor off, and theres nothing I can do about it (besides going to a full J&S knock system. Engine is running good and strong, pulls damn hard at the current boost settings and at WOT there is no significant knock counts. Tune seems good, idles good, starts good, keeps fuel trims in range, I have set the knock options to ignore below 3500 RPM and below 50% throttle input and have yet to have the CEL or knock gauge have any activity. only small blips of knock over 5500 rpm once the boost creep kicks in and boost goes to around 22-23 psi. Ill be turning the meth kit (blue washer fluid mixture (50/50)) back on tomorrow, and that should take care of the minor (less then a degree of retard) im getting at higher boost/rpm. I ran my own signal wire and ground wire to the knock sensor, but still got the exact same amount of knock as using the stock wiring, so that didn't get me anywhere also. Reconnected back as per stock.

 

[93'colttsi]

posting a update on this thread on what I finally figured out

ECU was bad and causing large fluctuations in all sorts of sensors and voltage. Changed the ecu and problem went away after that. too bad it costed 2 pistons and a engine rebuild in the end.