EFI project for M103 - PeachParts Mercedes-Benz Forum

ercuz · #1 09-18-2010, 05:32 PM

I'm planning to convert my terrible K-Jet to EFI (Megasquirt) + EDIS-6
But i have some questions from pro experienced friends
1-Which stock parts do i have to remove for installing the MS? e.g fuel accumulator,fpr,fuel lines,ovp or another else)
and i got 2 fuel pumps can i upgrade them for 1 more stronger pump than stocks.
Any advides??
Thanks.......

tjts1 · #2 09-19-2010, 05:37 PM

Hi
Check out the megasquirt link in my signature. The stock fuel pump will work just fine. I kept my stock fuel distributor intact and replaced it with another one that was completely gutted. This made room for the EFI fuel rail. The M103 shares its bore spacing with the M104 so you can use that fuel rail with slight modifications. I would leave the stock ignition system in place for now and just focus on fuel. Get it tuned right and then move on to ignition. You can get in way over your head by trying to tune both at the same time.
good luck
Justin

duxthe1 · #3 09-19-2010, 06:30 PM

I've been looking into this as well. The 103 isn't the easiest engine to adapt. From what I understand you can't use the stock flywheel for a trigger signal. Most adapt a ford 36-1 wheel onto the front pulleys for the trigger. That's not the easiest task either. I'm looking at fabricating a system that will be driven by the cam. The 36-1 wheel I have fits perfectly into the timing cover instead of the distributor. I'm thinking to turn it into a (2X)18-1 by removing another tooth 180 degrees which will be enough to time a 6 cyl engine from the cam. I have a line on what I believe is a 60-2 flywheel that will interchange but that is a huge undertaking on the 4-M and I will have to be fully committed before replacing the flywheel.

The fuel system is another consideration. The intake doesn't just lend itself to fitting EFI nozzles. I've fabricated some custom parts to mount, locate, and seal the injector. In stock form the 103 delivers idle air to each cylinder through the nozzle holder, an important consideration when making custom parts. I'll have to take a few pics of my parts when I can find the camera. (ie where did she put it?) I have no experience with this yet but I expect the stock fuel pumps to work fine. I plan to use a modified 104 rail and pressure regulator like mentioned above.

Yet other consideration is the tps. The 103 doesn't have a true tps. It's simply idle and full load contacts. You'll have to find and adapt a tps to the throttle body. FWIW, I have a spare intake manifold on the bench for trial fitting and experimenting, something I'd recommend you do as well if you have the means. My intention is to have a complete setup trial fitted on the spare intake. That way I can just swap over the parts quick and easy with no surprises.

EDIT: In picture two it shows the o-ring that seals the injector to the intake. It sandwiches between the nozzle holder and the injector body. The groove with holes is for idle air distribution. Not seen in the photos the holder has a 60 degree bevel between the injector and the tip of the nozzle holder.

ercuz · #4 09-19-2010, 07:23 PM

Quote:

Originally Posted by duxthe1

I've been looking into this as well. The 103 isn't the easiest engine to adapt. From what I understand you can't use the stock flywheel for a trigger signal. Most adapt a ford 36-1 wheel onto the front pulleys for the trigger. That's not the easiest task either. I'm looking at fabricating a system that will be driven by the cam. The 36-1 wheel I have fits perfectly into the timing cover instead of the distributor. I'm thinking to turn it into a (2X)18-1 by removing another tooth 180 degrees which will be enough to time a 6 cyl engine from the cam. I have a line on what I believe is a 60-2 flywheel that will interchange but that is a huge undertaking on the 4-M and I will have to be fully committed before replacing the flywheel.

The fuel system is another consideration. The intake doesn't just lend itself to fitting EFI nozzles. I've fabricated some custom parts to mount, locate, and seal the injector. In stock form the 103 delivers idle air to each cylinder through the nozzle holder, an important consideration when making custom parts. I'll have to take a few pics of my parts when I can find the camera. (ie where did she put it?) I have no experience with this yet but I expect the stock fuel pumps to work fine. I plan to use a modified 104 rail and pressure regulator like mentioned above.

Yet other consideration is the tps. The 103 doesn't have a true tps. It's simply idle and full load contacts. You'll have to find and adapt a tps to the throttle body. FWIW, I have a spare intake manifold on the bench for trial fitting and experimenting, something I'd recommend you do as well if you have the means. My intention is to have a complete setup trial fitted on the spare intake. That way I can just swap over the parts quick and easy with no surprises.

Thanks for replies

duxthe1 · #5 09-19-2010, 11:56 PM

A few more pics.

tjts1 · #6 09-20-2010, 08:13 AM

Duxthe1
Have you tried fitting EV6 injectors to your manifold? From what I can see, the injector holes and idle air setup is identical to the 8 valve M102 which was really easy to adapt to EV6 injectors. The injector nozzles are always under vacuum and are held down by the fuel rail as well so there is really no need to add another component to keep them down mechanically.
http://img.photobucket.com/albums/v242/tjts2/mercedes/DSC03114.jpg?t=1284984601
http://img.photobucket.com/albums/v242/tjts2/mercedes/DSC03116.jpg?t=1284984660
I'll get my hands on an M103 manifold in the next few days just to get an idea of any differences.
The throttle position sensor isn't really necessary for MS. I've had the M102 running without one for 15k miles now. All it does it fill in the gap between you pressing down the gas pedal and the MAP sensor reading a change in pressure. Even without any acceleration enrichment, MS has much quicker throttle response than any stock KE-jet setup i've ever seen.
If you're just doing a basic fuel setup, you don't need any toothed wheel. You can just use the negative terminal from the coil to get an RPM reading. I know people like to setup EDIS and other coil on spark type ignition systems, but the EZL system that is on the car is pretty good already. The spark timing maps on it are very good and adjustable, the only weak point is worn out distributor, wires and coil. Unless you're doing a turbo setup, I really don't see the advantage.
That said, your idea of fitting everything to the manifold (injectors, fuel rail, TPS, idle air etc) and then swapping the whole lot into the engine at once is a really great idea. It'll minimize your down time and you won't have any surprised down the road.
After doing MS1 to my M102 powered 190e, I'm looking forward to installing MS2 on the M103.

Hit Man X · #7 09-20-2010, 10:07 AM

See, I am opposite of you guys... I really want to convert my M103 to MS for timing mostly as that is where to expect real power gains. I do not really care about fuel economy gains.

Being able to go into power enrichment at WOT would be nice, but I believe the gains to be limited for the amount of hassle.

duxthe1 · #8 09-20-2010, 01:12 PM

I haven't tried EV6 injectors. The injectors I'm using are just regular 18.8 lb/hr bosch injectors. I'll be using those while naturally aspirated, and swap for bigger if/when I eventually get it under boost. With my setup I need the clamping bar to compress the o-ring to seal the nozzle. I'm not sealing off of the fatter o-ring near the tip, it mainly just locates the nozzle in the center of my custom holders. The rail will just be clipped to the nozzles with the stock clips with one safety strap to prevent the rail from getting accidently pulled up.

ercuz · #9 09-21-2010, 03:44 PM

Quote:

Originally Posted by tjts1

Duxthe1
Have you tried fitting EV6 injectors to your manifold? From what I can see, the injector holes and idle air setup is identical to the 8 valve M102 which was really easy to adapt to EV6 injectors. The injector nozzles are always under vacuum and are held down by the fuel rail as well so there is really no need to add another component to keep them down mechanically.
http://img.photobucket.com/albums/v242/tjts2/mercedes/DSC03114.jpg?t=1284984601
http://img.photobucket.com/albums/v242/tjts2/mercedes/DSC03116.jpg?t=1284984660
I'll get my hands on an M103 manifold in the next few days just to get an idea of any differences.
The throttle position sensor isn't really necessary for MS. I've had the M102 running without one for 15k miles now. All it does it fill in the gap between you pressing down the gas pedal and the MAP sensor reading a change in pressure. Even without any acceleration enrichment, MS has much quicker throttle response than any stock KE-jet setup i've ever seen.
If you're just doing a basic fuel setup, you don't need any toothed wheel. You can just use the negative terminal from the coil to get an RPM reading. I know people like to setup EDIS and other coil on spark type ignition systems, but the EZL system that is on the car is pretty good already. The spark timing maps on it are very good and adjustable, the only weak point is worn out distributor, wires and coil. Unless you're doing a turbo setup, I really don't see the advantage.
That said, your idea of fitting everything to the manifold (injectors, fuel rail, TPS, idle air etc) and then swapping the whole lot into the engine at once is a really great idea. It'll minimize your down time and you won't have any surprised down the road.
After doing MS1 to my M102 powered 190e, I'm looking forward to installing MS2 on the M103.

What is the main reason of you are thinking about MS2 or MS3 for your M103 project?
MS1 didnt handle your requirments?

RBYCC · #10 09-21-2010, 04:10 PM

Has anyone ever performed a base line dyno pull with the stock tuned CIS-E followed with a pull after the MS has been installed?

Yet to see any documented power gains from the MS...

tjts1 · #11 09-21-2010, 05:44 PM

Quote:

Originally Posted by ercuz

What is the main reason of you are thinking about MS2 or MS3 for your M103 project?
MS1 didnt handle your requirments?

MS1 extra has 12x12 fuel table vs 2 switchable 16x16 fuel tables on MS2, much higher injector PW resolution on MS2, better idle control options, more coded outputs. Basically more stuff to play with. If you have an automatic transmission with MS1, idle control tuning is a huge pain in the ass. Its doable but takes a lot of work. MS2 is much more intuitive. I don't know anything about MS3 except its out of my budget at this point.

Quote:

Originally Posted by RBYCC

Has anyone ever performed a base line dyno pull with the stock tuned CIS-E followed with a pull after the MS has been installed?

Yet to see any documented power gains from the MS...

8.1 sec 0-60, 15.8 1/4 with an 8 valve automatic + MS1. At this point the 2.3 auto with MS puts my stock 2.6 5 speed to shame. It actually got me worried that the 2.6 was down on compression but it tested fine. The most obvious benefit is getting rid of the restrictive Kjet fuel meter. Cold starts are instant, throttle response improves even without a TPS and fuel economy is always in the 28-33 range on 87 octane.

If anybody has a stock late model (first gear start) 190e 2.3 auto in the Bay Area, it would be interesting to do some side by side comparisons.

ercuz · #12 09-25-2010, 04:59 PM

i have installed Ms1 v2.2 and cables.All is done but i cant find aftermarket TPS sensor,which brand auto and model should i have to use?And same things for IAT and CLT sensors,can i use my stock CLT?

ercuz · #13 09-25-2010, 05:09 PM

i have installed Ms1 v2.2 and cables.All is done but i cant find aftermarket TPS sensor,which brand auto and model should i have to use?And same things for IAT and CLT sensors,can i use my stock CLT?

lee polowczuk · #14 09-25-2010, 05:45 PM

what's wrong with the stock efi.... i am confused

tjts1 · #15 09-25-2010, 06:07 PM

Quote:

Originally Posted by ercuz

i have installed Ms1 v2.2 and cables.All is done but i cant find aftermarket TPS sensor,which brand auto and model should i have to use?And same things for IAT and CLT sensors,can i use my stock CLT?

I didn't want to deal with easy therm so I used a GM IAT and a GM CLT epoxied inside a hollowed out stock Mercedes temp sensor.