Need a Spark Advance Table Chart from 502 EFI
 

Hello
have someone a spark advance Tabel from a 502 EFI ?

In the Mercruiser Service Manual 16 i can only see the advance from the voyager distributor module. But i can nowhere find something about a advance tabel from the ECM Modul ??

I drive today a 500EFI it makes total at over
2000 RPM total are in diacom 28*. Real 36* 28* + 8* = 36*

My 502 EFI
makes 2800 RPM 30* in diacom and real
than 3100 RPM 33* in diacom and real ( No Nock retards 33 + 8 = 41 this is not real and can not work)
than over 3200 RPM 28* in diacom and real
With real i mean showen with light gun timing tool.

Have someone a Tabel from this Engine ??
Ore now what advance this engines make ??

IIrc it is in the Merc manual 16, and also 23.

EDTI: Yep it is in # 16. Page: IGNITION SYSTEM - 4B-4

I have read this 4B-4 but i dont read anything about EFI only 502 MAgnum.
Its the same Distriburor but the EFI have a advances tabel in the ECM. The Distributor curve are only use for driving home in save mode i have read.

This is what my ECM do.

Is it normal ??

http://www.offshoreonly.de/phpbb/dow...e.php?id=23626http://www.offshoreonly.de/phpbb/dow...e.php?id=23626


http://www.offshoreonly.de/phpbb/dow...e.php?id=23629http://www.offshoreonly.de/phpbb/dow...e.php?id=23629

Your timing is fine. The Merc tables are strange as I alluded to in another post. If you have the TB-V it will also incorporate Mean Best Timing (MBT) and advance timing under static cruise throttle until it either detects knock or nor RPM increase.

The ignition advance at 40kPa (basically throttles closed) during heaving deceleration is 40 degrees on several Merc packages!

Thanks Trash for both replays.

You say it is normal, but what can i do to correct it. The hp500 dont do it.
Is it not better to stay at 36" at over 3200-4950 rpm i can drive ?

You need to change the Spark Advance/RPM/MAP table or timing table in the MEFI 1. Merc most likely reduced timing at the upper rpm and MAP points to minimize detonation potential. The Merc black motors (502 EFI) are more conservatively set up compared to the HP (blue) motors.

If your motor is running fine I wouldn't worry too much. If you are looking to experiment, then you need to alter the timing table. You would need MEFI burn software or get in contact with your previous tuner or one of the many other capable people on this forum.

I have no nock retards with 33* under 3200 RPM. Du you think i became nock retards with 36* over 3200 RPM ?

Can i run 16 Base Time to bacame 36* Total on WOT. What than are with under 3200 RPM with 16+ base time ?

Do you think someone have a fitting programm for the black old 502 EFI from 1993 that make what im looking for ?

If you have no knock under 3200 rpm and the ECM commands 33degrees timing then that's ok. I can't say if you will experience knock with 36 degrees of timing above 3200 rpm. It just depends on too many variables.

In order to test it you would have to adjust the timing table in small increments. MEFI Burn software will allow you to do this. If you are uncomfortable doing this then I would suggest talking with a tuner. Some of these guys can tune remotely which may be of some benefit due to your location. If the stock ECM is reducing timing at the upper rpms I would not worry about it as long as it's not due to knock. The factory timing tables in most cases reduce overall timing in the upper MAP and RPM spectrum.

You could, but I would NOT do this. You are trying to fix something that is NOT broken.

If your boat was tuned before I would talk with them.

If they didn't modify the MEFI 1 timing table I would leave it alone.

The timing curve you are seeing is most likely normal unless you are experiencing some significant performance degradation.

IF you are still unhappy with the timing the only answer I can give you is to get it remotely tuned by MEFI Burn, another tuner, or buy the software and change the timing table.

Thanks for als anwsers and help.

I think i buy the mefiburn solution.
I recorde and save the standart ecm hex9550 and the modifyed ecm hex9334.
Than i record and save the hp500 file.

Than i inspect all files and look what i can change.

If i see something are very difficult i can allways go back ore take a remote tune.

what year 502 and what is the stock cal id on the sticker on the edge of the computer.
mefi1 or mefi3-009 or 999

i will post for you the stock values

stock 502 mpi cool fuel mefi3-009

Main spark table based on RPM (3600-6000) and MAP (3600 MUST BE SAME AS PREVIOUS TABLE)

RPM* MAP
30 40 50 60 70 80 90 100
6000 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
5800 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
5600 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
5400 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
5200 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
5000 40.1 40.1 38.0 36.9 35.9 35.2 32.0 29.9
4800 40.1 40.1 38.0 36.9 35.9 34.8 28.1 26.0
4600 40.1 40.1 37.6 36.6 35.2 32.0 26.0 22.9
4400 40.1 40.1 37.3 36.2 34.1 28.1 23.9 21.1
4200 40.1 40.1 36.9 35.9 34.1 28.1 23.9 20.0
4000 40.1 40.1 36.6 35.5 34.1 27.8 23.9 20.0
3800 40.1 40.1 36.2 35.2 34.1 27.4 23.6 20.0
3600 40.1 40.1 36.2 35.2 34.1 27.1 22.9 20.0


Main spark table based on RPM (1200-3600) and MAP (1200 MUST BE SAME AS PREVIOUS TABLE)

RPM* MAP
30 40 50 60 70 80 90 100
3600 40.1 40.1 36.2 35.2 34.1 27.1 22.9 20.0
3400 40.1 40.1 36.2 35.2 34.1 27.1 22.9 20.0
3200 40.1 40.1 36.2 35.2 34.1 27.1 23.9 20.0
3000 40.1 40.1 36.2 35.2 34.1 27.1 23.9 20.0
2800 40.1 40.1 36.2 35.2 34.1 30.9 25.0 20.0
2600 40.1 40.1 36.2 35.2 34.1 32.0 26.0 21.1
2400 40.1 40.1 36.2 35.2 34.1 32.0 26.0 22.1
2200 33.0 33.0 35.2 34.1 33.0 32.0 26.0 22.1
2000 25.0 25.0 33.0 32.0 32.0 30.9 26.0 21.1
1800 20.0 20.0 30.9 30.9 30.9 29.9 26.0 20.0
1600 16.9 16.9 23.9 29.9 29.9 28.8 26.0 20.0
1400 14.1 14.1 14.1 28.8 28.8 28.1 26.0 20.0
1200 12.0 12.0 12.0 22.1 28.1 27.1 26.0 23.9


Main spark table based on RPM (200-1200) and MAP

RPM* MAP
30 40 50 60 70 80 90 100
1200 12.0 12.0 12.0 22.1 28.1 27.1 26.0 23.9
1100 12.0 12.0 12.0 16.2 25.0 25.0 25.0 23.9
1000 10.9 10.9 10.9 14.1 22.1 22.9 23.9 20.0
900 9.8 9.8 9.8 12.0 19.0 21.1 22.9 15.1
800 9.1 9.1 9.1 9.8 16.2 19.0 22.1 9.8
700 8.1 8.1 8.1 9.8 9.8 16.9 21.1 4.9
600 6.0 6.0 6.0 8.1 8.1 4.9 4.9 0.0
500 3.9 2.1 2.1 0.0 0.0 0.0 0.0 0.0
400 3.9 2.1 2.1 0.0 0.0 0.0 0.0 0.0
300 3.9 2.1 2.1 0.0 0.0 0.0 0.0 0.0
200 2.1 2.1 2.1 0.0 0.0 0.0 0.0 0.0

I was drawing a blank when trying to advise him on tuners other than Bob, but you were the other person I was thinking of.....

As I stated earlier this is typical timing for a stock MERC motor. They reduce overall timing as the rpm and MAP increases. The Scorpion motors and other small blocks are nearly identical, including the 40 degrees of advance on hard vacuum/snap idle conditions.

I think he's puzzled by seeing the advance reduce as the rpm increases above the mid 3000 range, yet that is normal. I've seen it on my motor too.

Im happy to find some people who understand me !!

Tunertech, this is what im looking for. This Tabel from a 502 Mefi3 is what i need in my 502 Mefi1.

I dont no, is somebody a company that reprogramms ?? Ore all only user with high technical understanding ?


My EMC Model are 16159919 Service 16165414 on the ECM.

when I get a chance I will post the MEFI1 table. You can not load the table I displayed into a MEF1, only change the slope factor

I will only change all over 2000 rpm.

80% Map Are the Most advanced in the Tabel.
At what point it use 100% ? Over 91% 95% 99% 100%
I've the engines is allways on map 100% what does it mean ?
Bigger Prop testing ?

Tunertech have you the same Tabels from a HP500Efi to compare ?

What total spark advance did a carb 502 run on WOt I've i check it with a light gun tool on WOT ?

I think I know why you are having a problem. Again, you DO NOT ADD your base timing to your spark advance reading from Diacom.

When you have the motor in base timing mode, 1500RPM, your timing light, if adjustable needs to be at 0. Then, you will line up your pointer to the 8deg mark on the balancer. If, you have an adjustable timing light set to 8deg, and mark your balancer/pointer at 8 deg, then you have 16deg base! This is a common mistake. If you have your adjustable timing light at 8deg, then you MUST line up your pointer and balancer at the 0deg mark.

The best timing lights are the very cheap, non-adjustable that run off a 9v battery. Then you just line up your pointer and balancer at 8deg. Then this is exactly what the ECM is looking for base and there is no way the timing light can be off.

Looking at a stock table will not help you since your table is already modified. A stock 502 had 26deg total advance at 4800, you have 29.

I have one genV and one genVI. So i need a timing light that can adjustet.

I adjust the light to 8 and move the light an baloncer plate with the distributor to 0. all in base time mode.
Than i doppel check it with adjust the light to 0 and show on 8 on the baloncer plate. Thats fit. The other genV have only one point plate stick, i hope this is 0. i adjist the light to 8 and it points on the stick 0.

So if this is correct both on 8. both have the same Hex9334 software modifed ore hex9550 original. Both softwares make 29.53 total at WOT.

You mean this are 29,53+8=37,53

I have test 6 base time with better speed but most i have test more base time 9,10 and 11 but this are bad at midrange.


Have someone a unmodified tabel from a 1993 mefi1 ? For see the diffrence to my to versions ?

MefiBurn are arrived.

This is my unmodified EMC from 1993 (HEX9550)

http://www.offshoreonly.de/phpbb/dow...e.php?id=23689

You keep adding 8deg to your total timing which is wrong.

Don't add 8 to 29.53, its already included in there.

Base timing is a reference point. The computer already assumes it has 8deg base timing. If its not 8 deg, it does not know it. Now that you have the software, leave base timing at 8deg and adjust accordingly. There is a slope on the MEFI1 ECMs.

This is easy to calculate. You take the "UPPER RPM THRESHOLD" which is where the spark slope will stop increasing. Example, 5000rpm.

Subtract 3600 (last rpm on main spark table) from 5000 (upper rpm threshold) and this is 1400rpm.

Now multiply 1400rpm to your "SLOPE", example .0028500.

This is now 1400 x .0028500 = 3.99 (round to 4deg). What this means is that it will take your spark advance from your 3600rpm row, and add 4deg in a slope until 5000rpm and then it will maintain.

Example:
3600rpm = 28deg
4300rpm = 30deg
5000rpm = 32deg
5200+rpm = 32deg.

Therefore you can play with the RPM and Slope to get the desired curve you want. If you don't want any slope, and want to run full timing rom 3600rpm and up, then you can put 0 in the slope and 3600rpm in the offset.

If it were me, and I was tuning for 98 RON, I would run 28deg at 100kpa/3600rpm, 29deg @ 90kpa/3600rpm. Then I would run 5000rpm for offset, and a slope of .001500.

Hello Whipple Charged,
thank for all the infos. That is what im looking for.


This Software and alle the programming are a newworld for me.
I allways stay in the years, Carb and Distributor.

Why are the EFIs not go so high with the total Spark like a carb. Carb 34-36 vs EFI 26-29 ??? Is it the camshaft ??
MAP 100 are at full RPM ore 90 MAP are at full RPM the curve the ECM chose ??
Some EFI Basics i need for better understand, are there a webside i find some good informations that help me ?????

The HP500 are password looked, so i can not read it out. Have someone a *.bin File from a HP500 ore something like this engine ?? [email protected] are my email. Thanks.



modifed from a tuner company
http://www.offshoreonly.de/phpbb/dow...e.php?id=23692



original
http://www.offshoreonly.de/phpbb/dow...e.php?id=23691

Carb vs EFI should run same spark curve. But with a 8.75:1 compression motor, with cast iron heads, small cam and Euro 98 octane, 32deg is max power.

What is your stock cal checksum? Its the white sticker on the side of ECM?

Running 29deg at 3600rpm is very aggressive if you don't change the factory slope.

500hp runs 28.8deg of timing until the rev limiter (5400) which calls for 34deg.

Stock are the Original Second picture 9550.

Before I change anything I will check it again next year.
I drive WOT 4960 rpm and look the total advance with the light gun tool.
If it is only 29 on the gun and 0 at the balancer mark I will change the ECM to 32. If it is 37 on the gun and 0 on the balancer I change the ECM to 26 back.

What about the midrange 2300 rpm with twin engines it a good cruse rpm but it makes 40 there (48?) is it not to much for long drive ?




Where I find the Slope on the software ? Tunerpro ?

The slope are displayed on diacom ore not ?

Slope....... this word is working in my brain for some hours. (5 hours) :-)

This is the reason for all my addions dont work on WOT befor. The slope are not displayed from rinda diacom on the record files, true ?

Does a H500 make the same "slope" over 3600RPM ore have it a tabel with more than 3600RPM build in ?

I found the slop and the other things.
This are original 9550 and the reprogrammed 9443.

Slope for tabel F1 are the same.
upper RPM threshold for F1 tabel. moved from 5000 to 3600 ?

Original max RPM 5080
http://www.offshoreonly.de/phpbb/dow...e.php?id=23725

reprogrammed max RPM 5400
http://www.offshoreonly.de/phpbb/dow...e.php?id=23726

Can this be my problem the 3600 upper Threshold for F1 table ??
The slope have no funktion Upper tabel RPM 3600 to upper threshold 3600 RPM are 0. 0 x 0.00396 = 0 yes ??
This 29,53 total from 3600 and up ....5000 and more ???? yes ?

What ere the max retard relative to TDC ?? This are diffrence ?? Are something with Nock Retard ?

Whipple-charged what do you think ?

Have i say something wrong ?? Than i say sorry.

This is what are changed from original right one to left new one.

http://www.offshoreonly.de/phpbb/dow...3794&mode=view

Looking at your left table it does look like one I have but with the stock rev limit, not 5400. The origin of that file is a little unclear but I have notes telling it could be an Arizona Speed Marine modification.
However I do also have a file which I have marked Stock 502 MPI and that one is still little different from your table on the right. There is a possibility that there are a few different files for 502 MPI out there released from Mercury.

All have see what im looking for, now i have delet the pictures.

Hello Alex
you are from sweden ?
I have a EFI, its the same i now, but it was one of the first programmed 502 in the year 1993. So im looking for some programmes from later models.

Have you some files for me ?? Stock ore modified ? My email are [email protected]

my idea are, i set to:

High RPM Fuel Cutoff 5240
upper RPM for F1 4800
Slope for F1 0.00363
max advance to TDC 38.1
all 40.1 in the tabel set to 38

map 100 = 3600 = 29.9
map 90 = 3600 = 28.1

Max than at WOT 34.256

Mike,

I have mostly been modifying for super charging, don't think I have anything ready for you. If you have MefiBurn you can download your current mapping and modify to your wishes.
Send me a pm or email me at [email protected] if you want to discuss more details.

I have changed some small numbers and it works very nice with my engines. Boat runs 9kmh more now.

I have now another question.


Fuel.

What Fuel are better for my engines ??

95 E5
95 E10

Did it make a diffrend Fuel Tabel ore spark advance ? Ore did i feel no diffrence ?? I have a little diffrence in $. :-)

I have used my programming this full summer time with no problems.

I'm right with my black engine theory.

Hp500efi have 500hp this are 470hp propshaft.
502efi have 415hp propshaft.
55hp different
With better exhaust and open the upper Rpm programming the engine became some more power.
I don't not now how many more, but it is a lot more.

I changed from 72 to 80 in cold and 78.8 in hot weather, twin 502 engines.

The Mefiburn makes a perfect job. Thank you to Bob and all the help and time he did for me. Thank you.