Spark tables

[monaro308]

Hi all,i have a couple of questions regarding the BLCF spark tables in 12P.
It has been mentioned that the tables were an average looking set of numbers.
Does anyone have a pic or log of what a smooth looking table set of numbers that have worked for you on a standard 5lt.
My red motor EFI setup might react differently to your numbers but the reason i'm asking is.... lately i have been having constant pinging on light load accel anywhere from 1000rpm-1800rpm.
Its more noticeable at around 1500,1600rpm.
Afr's,base timing etc all aok,but i am tuning at the moment in open loop and knock enabled.
I run 95 fuel and have been using 95 since day 1 and also 12P with out a hitch.
I thought maybe a winter mix but i reconnected my LPG and it also pings in the same range....which is very strange for LPG.
Does open loop effect EST parameters ? I haven't switched back to closed loop yet to find out but curious to know if anyone has had issues with light load pinging.

What steps do you all take to set up your spark tables inc your idle spark table ?

cheers..mario

[vn5000]

Just a thought ,but have you checked base timing to be sure the dizzy hasnt moved .
Also have a look at your datalogs to see if the ecu is detecting the knocking and see how much spark retard its applying.

[Holden202T]

you've mentioned the base timing is ok, but is there a possibility the balancer has spun ?

i don't know enough about 5ltrs but i know on a holden 6 its a common issue for standard balancers to spin, thus when putting the engine into diagnostic mode and setting base timing this will put everything out.

other than that i'm wondering if you are getting a carbon build up in the chamber which could cause hot spots and cause your issue ....

generally i would think a stock timing map should be reasonably hassle free on most motors, but then without knowing whats been done to the motor etc its hard to say, but if your engine never used to ping and now it is, then something has to have changed to make it do it.

have you changed the thermostat or anything that would make the motor run hotter?

[monaro308]

Yep base timing set and a log i did a while ago showed knock under WOT and load ie up a hill and from memory retarding about 9 deg,no knocks detected under other conditions.
This pinging is happening under very light loads and even on a steady cruise at approx 60-70kph.
If i get time tomorrow i will try and get a log on both fuels although i'm running motec PLM (will have to wire it in oneday for TP WB display)but as i said AFR's showing all ok.

Just caught your reply Sam, no nothing changed in the motor since day 1 and its stock as a rock and engine temps running about 90deg C.
I'll do a TDC check on the balancer when i get a chance but dissy hasn't been touched since fitted.
I'll also flash it with the original 12P bin and see if it fixes it.

Has anyone done a write up on the way you set up your spark tables,i've never really had to do any major tweaking as like you said the stock maps have been fine.

Cheers..mario

[Holden202T]

well assuming your balancer and dissy are set right then you pretty much go off the knock sensor, if its showing knock at cruise loads then remove a bit from those areas and see what happens.

without a dyno theres really no "perfect" way to tune knock other than to remove a few degrees of timing where its knocking.

anything thats removing 9 degrees is a huge amount and i'd be suprised if you can't hear it by ear!

[Jayme]

Unless its false knock... u got a v8 knock board?

[monaro308]

Yeah Jayme V8 knockboard and running Ostrich 2.0.
I mentioned a while ago when D/L that it recognises its an 8 cyl but detected as 6cyl.

The knocks are detected under very high load and timing backs off anywhere from 3 deg to 9 deg depending on how long i keep my right foot into it
The pinging (which is different to knock) is a different story and is there on very light acc/cruise.

I'll get a log 2morrow night as is and then i'll re-flash with the original BLCF 12P bin with all the closed loop/knock disabled params etc and log that just to see if that fixes it.
cheers...Mario

[monaro308]

Well after a bit of hair pulling and checking everything over the last month for the annoying pinging at very light throttle loads,it came down to tracing one cylinder pinging..#6.
I resorted to chocking the wheels,car in drive and handbrake on and standing to the side with one hand on the throttle and a vacuum hose stuck in one ear checking each cylinder for the ping.
I found with raising the revs very slowly it would constantly ping at about 1400 revs on # 6 cylinder and the noise would get louder through the hose around the exhaust port headgasket area.
I then noticed a very slight oil trail at the same spot and then it clicked
When i did my conversion 4 years ago i removed the pollution heads to put my bigvalved pre-pollution heads to suit the pre poll manifold that i modified for the injectors.
When i removed the heads,it broke a headbolt (rusted in),drilled a hole and broke an eazyout (i f'n hate them even more) then spent 2 days grinding that f-er out without damaging the thread area.
Anyways...the noise/pinging was at the same spot.....thats when i knew it was either a gasket or broken bolt/thread.
Pulled the ex/manifold off and checked the head bolts.....sure enough the same bolt had bugger all tension and wouldn't clamp anymore.
Off with the head and hoped there wasn't any damage done from the pinging etc.Thread looked so so and the bolt looked wasted/stretched.
All was good and clean and even the head gasket looked good,so i hoped it was only the bolt causing the issue and the pinging noise was most likely comp/firing noise leking past the gasket and not
pinging.
Next pain was the helicoil kit here was $75-$90 and i only needed to do the 1 thread
I found a new kit in the US that a bloke had sitting around left over that came from OZ (recoil) for $15.00 delivered to my door
Drilled out the thread,tapped the new thread,screwed the insert in and slapped it all together and all is good!!

SO WHAT HAVE I MISSED AROUND HERE??