Help what Company programs MEFI1
 

Hello I need help.

What company programs mefi1 ECM ?


My last program make keitheickert.
I have post him, but he don't have time for me.
I take to many time for the last support.
It was 2011 and now I like to program something diffrend.

What company can do this.
Change the spark advance table on my HEX9334 mefi1 ECM.

Thank for all help.

i use mefiburn.com also called obd diagnostics .real good guy to deal with

Precision Marine in Louisiana has a good reputation. Also mefituning.com ...don't know much about this guy, but he seemed pretty sharp when I talked to him.

Scott from Keitheickert have time for me and help me again. Thank Scott for your Help !!

Bob from MEFIBurn can help. If you are savvy you could get the software and work on the timing table yourself. MEFI 1 is one of the easier ECMs to play with simply because it lacks the complexity and fidelity of the later MEFI units.

www,mefituning.com

What do you think about this ??
Is it normal ??

Where is the problem ?

This old ECM shows the real total advance in Rinda. The 29.53* at WOT are real with light gun tool.
The 33* befor 3200RPM are real too.



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

This is a HP500 and Rinda shows the advance. 28 + 8 = 36




http://www.offshoreonly.de/phpbb/dow...e.php?id=23630

Are your engines stock????? If yes, then just run a stock mercruiser ecm tune or one that is slightly modified.

20 years stock.
4x rebuild with new engine blocks and allways stock. Only thumber power exhausts.

I have stock ecm Hex 9550 and modifed ecm hex 9334 from keitheickert. Both did the same.
Is this normal ? Ore are something else wrong on my engines ?

Those timing values appear fairly normal. Of all the stock timing tables I've seen Merc tends to reduce timing at the upper rpm and MAP of the table. For instance it might have 34 degrees at 3200 rpm and 70 kPa but at 5200 rpm and 100 kPa it might be 28-29 degrees. These numbers are only shown as an example and NOT actual values you may have on your table.

Bottom line, most cases I've seen timing reduced as you go to the upper RPM/MAP cells as compared to mid range cruise values.

I think you are confused on how timing works on a MEFI ECM. All stock Mercury Marine EFI motors are shipped with 8 deg's base timing (set only in base timing mode). This, base timing is included in the total timing shown in the scan tool or data logs. The ECM does not have a function to know what real world timing is. So if base timing is off, say 4 deg, then the scan tool would show the commanded timing, but your timing would actually be 4 deg's retarded.

So a 500hp EFI does not have 36 degs! In the software, you can change what base timing is, but Mercury has always used 8 deg's.

The one thing Mercury Racing did, and it was only on the 500hp EFI is that ALL 500HP EFI's have the ECM set at 8deg base timing, but all new motors were shipped with the timing set at 10deg base. Meaning when the ECM showed 28deg, it really had 30deg (with timing light).

With your calibration showing 29deg's timing, you already have a modified ECM and 29deg is about all you should run with Euro 95 octane. With your 98 octane, you can run 31deg. To change, just put your motor in base timing mode, and move your base timing from 8 deg to 10deg. This would give you 2 deg more advance. If you want less, just take 2 out.

Note: Any good calibrator will run more timing at part throttle to increase engine efficiency, better mileage, less soot while there is low cylinder pressure and less possibility for detonation. So I see nothing wrong with more timing at lower manifold pressure.

Yes you say it. Hp500 are 28 on software and 36 in real.

I have 29,53 on software and in real. I need 15,5 basetime for 36 real.

NOOO, 28 on scanner, 30 real if timing if base timing is 10deg. If base timing is at 8, then its 28deg just as scanner shows.

You don't add your base timing to your actual timing. The ECM assumes base timing is 8deg. DO NOT RUN 36 DEG TIMING!!!! If you want more, bump your base timing to 10 deg instead of 8, this will give you 2 deg more, but your scanner will still show 29.53.

I have test it with 8 9 10 and 11 base time.

8 base, diacom 29,53 real 29-30
11 base , diacom 40 real 43 nock retards.

Hmmm, a discrepancy...

Yes, that is my problem.

Can it be, first black EFI 1993 are shows "TOTAL Spark Advance" and newer and blue Engines shows "Spark Advence" in Diacom ?

No, it has no way of knowing where the motor is to know actual timing, you would need a crank and cam sensor for that to truly happen. If you are changing base timing 2-3 deg more and your getting that much advance, you've got another issue such as the dist itself. The parameter in GM's software is "commanded timing" meaning its commanded, not actual.

I have ordert mefiburn software from Bob.
I will read all the date from my efi ecms. Than i now more what the engine is programmed to do. My rinda records shows me what the engine do.
If i now more i will tell.

Make sure your ECM isn't password protected or make sure you have the password otherwise you won't be able to get the data you are looking for.

This is my old ECM, original from 1993 HEX 9550.

This i have read out from the ECM.
Tomorrow i read out the new modified ECM and a HP500 ECM.

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

Now i have the programm MEFIBURN for some month and i have read out some engines.
Now i have see some differences in programming Mefi1 and mefi3.

HP500EFI MEFI3 the Main Spark in RPM/MAP are going up strade, like a old Sparkmodul from thunderbold. 35.9 over 5000RPM Fuel goes up to 5000 than up to 6000
502EFI MEFI1 use a loop over 3600RPM x1RPM to UPPER RPM 5000RPM. 30,5 over 5000RPM (Limiter 5080RPM) Fuel goes up to 4800 than up to 5200



Now my idea for my ECM MEFI1, what do you think ??

Limiter 5200RPM

Loop 0,00417
upper RPM for Loop 4800RPM
= 5,00


Main Spark
3600/100 29.9
3600/90 28.1
3600/80 32.0
3600/70 35.9

BPW vs MAP/RPM
4400 2.70 4.20 6.40 7.50 8.60
4800 2.60 4.20 6.30 8.00 9.20
old
5200 2.70 4.10 6.10 7.30 8.60
new
5200 2.70 4.20 6.30 8.00 9.20



??????

Or is it better only

Loop 0,00417
upper RPM for Loop 4320RPM
= 3.00

+29.9=32.9 over 4320RPM and MAP 100

So im back from testrun.

The 34* give 0.75* Nock Retards, so im ending with 33* and no Problems.

Slope 0.0045 end 4300
Tabel 29.9* /100MAP
9.2 Fuel with 30PSI

4970RPM with 30" Bravo LAB

Why is the fuel pressure so low? Should be at least 43psi. I would bump up your fuel pressure and turn the bpw down a bit. You're working the hell out of those injectors at 9.2ms.

I believe Mike has an early 90's 502 EFI. That should be an engine that used 38 psi as opposed to my late model 502 MPI that uses the higher
fuel pressure(42 psi). As you pointed out, 30 psi is way too low.

Hello yes i have a engine from 1993. I buy some new standart fuel pressures and testet them with the gauge (mercruiser fuel press tool) and allways 32 psi.
With 34 psi the boat are slower.


The bpw is it testet ore a calculatet number ? I dont now what i put in for better higher rpm.

What are better: test with more psi ? Ore more bpw ? Ore more psi and less bpw ?

Are you tuning with a wideband O2 so you can monitor air/fuel ratio? Others may chime in but in my opinion, you're driving the injectors too hard at wot. Most injectors are built to run at 80% duty cycle which in my experience translates to a max of 8.0bpw. Pushing them into the 90% range could potentially lead to failure. And, at WOT... that could be disastrous for your motor. I don't know what your motor combination is or if you're just trying to improve the tune on the stock setup. However, if it were me, I would raise fuel pressure and try to get the duty cycle of the injectors down a bit. The only way you can do this effectively though is to monitor af ratio with a wideband O2 as you're running the boat. To raise fuel pressure you may also need to install an aftermarket regulator so you can adjust.

Hello Griswald, thank you for the replay.

I like to tune the stock setup from the old model. The 9.2BPW are from the stock ECM with 4800RPM. But the stock goes than down to 8.0 at 5000RPM. My idea was to holt the 9.2 to 5000RPM. But i can make more PSI, i have a manual adjustable fuel pressure regulator and go to 8.0 but i dont now what to do with the rest of the BPW Tabel.
I have Imco Thumber Power Exhaust and i have no Air Fuel Ratio meter.

At time i run PSI30 (32) and BPW all at stock. Only the small change on 5000RPM to 9.3BPW and the Lope total 3* ending on 4300RPM and 29.9* on MAP100 at 3600RPM. No Nock retards.

I have record files from diacom with twin record and i have ECM files with the programming i have make.

I have test a little bit more PSI (32PSI) with 9.2 and the speed goes down.
I have test with the 31PSI and more BPW 9.5 and the speed goes down.

Is the BPW are fix from 4800 to 5000RPM ??? Ore what BPW at 4950 i have ?


Hello Griswald,
do you think the injectors are damged if i drive WOT for only 5 Minutes ?? I can only drive for only 5 to 8 Minutes at WOT on my river.

No way of telling if the injectors are damaged. You could take the wire harness of a few and ohm them out with a multimeter. They should all be 11Ohm or higher.

The increased fuel pressure may be making it rich and slowing you down. Just a guess. I'd really suggest getting a wideband 02 sensor so you can monitor air/fuel ration while you're running.