spark advance

[mecanicus]

Hi everybody,
is there a tool like trimalyzer for the spark advance table?

I could convert my amc 304 engine to tbi.When I used the original spark advance table from BPSA.bin the car didn`t run right. I have set the table according to the spark advance curves from the jeep-manual. Now it runs good when rpm is higher than 2000.At lower rpm and when accelerating i have to do that very smooth otherwise engine is bogging and trends to stall.I raised up spark advance in lower rpms slightly but no success up to now. When I take an other bin (bhmc) from a 5ltr engine, engine will not accelarate at all.
Attached my last logfile where ve tables are not yet set by trimalizer.

[steveo]

trimalyzer does have a knock analyzer built into it but knock analysis is as good as it gets, no tool will automatically tune spark (too dangerous, needs a practiced hand)

spark advance is tricky for sure

keep working on your custom table based on the jeep manual and don't forget that timing isnt' everything, maybe fuel has something to do with it too. where it bogs, add a few more degrees and see what happens. in areas of light load and low rpm its harder to cause damage.

[mecanicus]

Hi Steveo,
thank you for the quick answer.
Yes i have already realized the Knock table in your trimalizer.I have 4 big knocks in there.When I analyse the log.csv in excel, there are 5 knock retards.
Do I have to decrease my spark advance or increase it at those cells?
When I have the history running in tunerpro-rt I can see the knock retards in those cells but they are overwritten next time when no knock was detected.
Is there some manual about spark advance?

[steveo]

if it's knocking definitely remove some spark advance. if it still knocks there remove some more. if it still doesnt' go away you might have false knock (mechanical noise or knock filter no good for engine) or it's lean knock.

i'd focus on the areas with groupings of knock events, those are probably real.

honestly i can't imagine your knock sensor and its filter are proper for your amc engine so you might not be able to trust it? you'll find out when you try to tune it back a bit

[mecanicus]

Hi Steveo,
thank you for the quick answer.
Yes i have already realized the Knock table in your trimalizer.I have 4 big knocks in there.When I analyse the log.csv in excel, there are 5 knock retards.
Do I have to decrease my spark advance or increase it at those cells?
When I have the history running in tunerpro-rt I can see the knock retards in those cells but they are overwritten next time when no knock was detected.
Is there some manual about spark advance?
As well i saw that my park brake switch is on all the time. I know I havent connected the pins because I could start the engine with and without connection.Does that matter on the behaviour of the engine?

[mecanicus]

Hi steveo,
your answer was too quick, I wanted to add this question: As well i saw that my park brake switch is on all the time. I know I havent connected the pins because I could start the engine with and without connection.Does that matter on the behaviour of the engine?

[steveo]

park brake or transmission park/neutral?

they're very different things.

i've never seen an oldschool GM ecm where the park brake switch does anything

park/neutral or shift position switch definitely could if you're running an automatic bin.

[mecanicus]

Hi steveo
it is an 16196395 and my bin is set to manual transmission! In the csv it was the park brake. So I think this signal will not work on the programming.
In the meanwhile I had a look to John Wilson`s "How to tune a GM EFI System" He wrote he has an excel sheet what calculates spark advance based on spark advance out of the manual given at 100% MAP.He would sent it on demand.
Unfortunatelly he is no longer reacheable on the internet.Does somebody have his spreadsheet or his new email adress and is willing to provide this to me?

[stew86MCSS396]

Hi everybody,
is there a tool like trimalyzer for the spark advance table?

I could convert my amc 304 engine to tbi.When I used the original spark advance table from BPSA.bin the car didn`t run right. I have set the table according to the spark advance curves from the jeep-manual. Now it runs good when rpm is higher than 2000.At lower rpm and when accelerating i have to do that very smooth otherwise engine is bogging and trends to stall.I raised up spark advance in lower rpms slightly but no success up to now. When I take an other bin (bhmc) from a 5ltr engine, engine will not accelarate at all.
Attached my last logfile where ve tables are not yet set by trimalizer.

Don't waste your time using any of the stock Chevy timing maps. To be honest, I know nothing about AMC engines and what they like for spark timing. My approach to this would be to do a Google search for a AMC 304 spark timing table. There was one hit that I saw that they were using megasquirt. Perhaps you could experiment with that. https://grassrootsmotorsports.com/fo.../118096/page1/

Arghh...just reread it's referring to a AMC 360...

[steveo]

everyone needs to stop interchanging the letter O with the number 0 in mask names.

masks are hex, there's no letter "O" in hexidecimal

this will help you when searching for information about masks like 0D and 0E (also help others that might be searching for threads and posts like this one)

[mecanicus]

Hi steveo
you are right, so I wouldn`t mind if an administrator would correct this!

[84Elky]

Two things that may help:

• A VSS is necessary in most all applications because there are many IAC positioning and other decisions made by the ECM code based on whether the car is moving or not. This applies to both manual and auto cars. Does not affect spark, but does many other important items.

• Playing hit or miss with spark is difficult. Best to just build a table based on your requirements. This may help: https://www.thirdgen.org/forums/diy-...ml#post6301288

One other general note. For those who don't have the ADX for your mask, it's always helpful to post a .csv or .xls* file that you export with your ADX rather than posting the XDL. More people might be inclined to review the log and help if this if done.

[mecanicus]

After some tries and errors, i could build a spark table what seems to work on the engine. But engine is not running round and when having a look to the graphs, I see some spikes in rpm. Could the ICM cause these spikes or should I search for an other fault?
The txt(csv) file is only a small part because its real size was too big for the upload.

[1project2many]

Hi steveo
you are right, so I wouldn`t mind if an administrator would correct this!

I have corrected the offending messages in this thread.

[mecanicus]

Now I have changed the icm with brandnew one but the same spikes and interruption in ignition.
What to change next ? ignition coil ?
What other options do I have?