Tuning with CIS - Page 19 - PeachParts Mercedes-Benz Forum

JayRash · #**271** 09-12-2011, 10:33 AM

For the EZL just plug a resistor equal in value to those found in the euro knob and it will run like ur using the knob. fairly simple.

gsxr · #**272** 09-12-2011, 11:30 AM

Each EZL has a maximim of 7 maps. If the Euro EZL is the same part number as the USA EZL (for a given engine/chassis), the maps are identical, however a different one may be selected by the factory depending on the destination country. Now if the Euro models spec'd completely different EZL's, that's a different story. This is not the case with the M119's (same EZL's used worldwide) but I never looked into the M103's.

RBYCC · #**273** 09-12-2011, 03:18 PM

Quote:

Originally Posted by gsxr

Each EZL has a maximim of 7 maps. If the Euro EZL is the same part number as the USA EZL (for a given engine/chassis), the maps are identical, however a different one may be selected by the factory depending on the destination country. Now if the Euro models spec'd completely different EZL's, that's a different story. This is not the case with the M119's (same EZL's used worldwide) but I never looked into the M103's.

Dave

Going back to your document library and the thread on the fixed R16/1- 750 ohm reference resistor as installed in the USA EZL.

EZL part number 013 545 78 28 adjustable settings:

1 infinite o degrees 98 octane
2 2400 ohms 2 degrees 95 octane
3 1300 ohms 4 degrees 93 octane
4 750 ohms 6 degrees 91 octane ( the us setting typical)
5 470 ohms 8 degrees 89 octane
6 220 ohms 10 degrees 87 octane
7 0 ohms 12 degrees ?? octane

The fixed USA resistor is set for 6 degree retard and if the USA EZL has the same 7 maps built in then wouldn't removing the resistor ( as I did ) provide infinite resistance ( open circuit zero current flow ) and allow access to the same map as the 1 setting on the subject non USA EZL?
If so you would then advance the timing 6 degrees.

Ed A.

JayRash · #**274** 09-12-2011, 04:35 PM

yup, exactly Ed.

gsxr · #**275** 09-12-2011, 07:22 PM

Quote:

Originally Posted by RBYCC

The fixed USA resistor is set for 6 degree retard and if the USA EZL has the same 7 maps built in then wouldn't removing the resistor ( as I did ) provide infinite resistance ( open circuit zero current flow ) and allow access to the same map as the 1 setting on the subject non USA EZL? If so you would then advance the timing 6 degrees.

Yes - assuming the chart above is correct for your car. The chart may vary for different model years, engines, chassis, or EZL's. And not all M103's will necessarily be the same. There is not a single "one chart fits all".

Note the M119 chart below has totally different timing data for each resistance spec:

duxthe1 · #**276** 09-12-2011, 07:54 PM

When I was going through and testing trim resistors for the turbo install, I couldn't correlate my findings with the chart. I do believe the tendency less resistance = less timing but I'm pretty sure it's not one map and +- "X" degrees across the board. I think each map is unique in their part and full load timing, but all of them seem to be within 1-2 degrees at no load conditions.

While I'm working for less timing, I know you guys are working for more. Have you considered lowering your octane instead? There is more chemical energy in lower octane fuel and if you're trying to tune it to the edge of detonation, there may well be a few hp with the stock advance and more volatile fuel.

400Eric · #**277** 09-13-2011, 03:59 AM

Quote:

Originally Posted by duxthe1

Have you considered lowering your octane instead?

I'm already doing that. I'm running regular gas!

Quote:

Originally Posted by duxthe1

There is more chemical energy in lower octane fuel

I wouldn't exactly put it that way. It's about the same amount of energy but that energy is more accessible in the lower octane fuel.

Quote:

Originally Posted by duxthe1

if you're trying to tune it to the edge of detonation, there may well be a few hp with the stock advance and more volatile fuel.

Agreed. And the fact that I still haven't had any detonation even on regular grade fuel proves to me that I'm still not getting enough advance, and I'm not getting it early enough. Even with Jay's mod that prevents timing retard when the engine is warm, and even with the warm engine temps and the hot days that we've been having, there's still not even a peep of detonation!

Like I said, MB went way too conservative with the advance curve on these M103s because they didn't have a knock sensor on them to bail them out if things got too testy. So they just went with a real mild advance curve instead. Kind of a C.S. way to do things in what was a $40,000 car if you ask me. In today's dollars, that $40,000 would be more than $63,000! That's enough to buy a C63! Later M104 CIS-E EZL cars had knock sensors, I mean really! Would it have killed them to put them on the M103s too? On a $40,000 ($63,000) car?!? Are you kidding me?!?

Dave, what about that post on the other thread where you said that the factory literature said that even though the advance increased with the removal of the resistor, it was decreased under WOT. (By 3 degrees if memory serves.)

Taking Ed's point a point further, I am just trying to increase the advance amount below 3,000 RPM at WOT so I can get out of the hole quicker. My 60 foots suck! I'm not after more advance beyond that although I wouldn't mind it as, again, I think it's way too conservative because I shouldn't be able to get away with using regular!
Regards, Eric

400Eric · #**278** 09-13-2011, 07:47 AM

Found the post I was/am referring to on page 23, post number 333 of the "Zombie Thread".

Quote:

Originally Posted by gsxr

Some factory docs out of the WIS which may help answer some of the EZL trim plug questions (these are PDF files) :

Trim plug function

Ignition timing adaptation

Note that the resistance for each position (1-7) is always the same, but the "N" and "S" designators may change to different numbers depending on the version (KAT, non-KAT, auto trans, manual trans, etc). There still is no simple document showing which position offers which timing change, probably because - as Hartmut said - it's different for each EZL/engine!

Also of interest is the information I found in the Engine Diagnostic Manual Vol. 1... this also shows how the resistances are different for each (USA) engine, and can vary by model year:

Engine 102.985, 09/88 to 08/89 - resistor is 750 ohms, zero timing retard
Engine 103.94x - resistor is 750 ohms, zero timing retard
Engine 103.98x - resistor is 750 ohms, -6° timing retard
Engine 104.98x - resistor is 2400 ohms, zero timing retard
Engine 116.965 - resistor is 750 ohms, -6° timing retard
Engine 119.960 - resistor is 2400 ohms, zero timing retard

There is this comment after each reference resistor spec in the manual:

Note: If the reference resistor is missing, the ignition is retarded 3° at wide open throttle.

Finally, I found this gem, note that it shows this applies from model year 1988-up (which may explain why there was a loss of power & economy on my 1986 model 300E):

EZL trim plug positions, M103.98x

Ed, you once told me your 88 CE is still running it's original EZL and you shared with me it's part number but now I can't find where that number is posted. (I can't remember exactly when it was and you have a lot of posts!) Could you please post that part number again? My 88's EZL part number is illegible. I don't know if it's been changed and I'm curious if I should try to run another one with the correct number for that year to see what, if any improvement there might be found in low end. (I'm trying to make BOTH of my M103s quicker.)
Regards, Eric

JayRash · #**279** 09-13-2011, 08:01 AM

Eric, for my mod try running something like 1.5kohms or alittle above like 1.6kohms. and tell me if it makes any difference pls. btw i leave to Ohio tonight

RBYCC · #**280** 09-13-2011, 08:10 AM

Eric

Bringing timing in quicker will not improve your 60' time....in fact it can increase the 60' time.

If you're having problems launching then more power won't help.

The 60' time is totally dependent on launch and traction and has more to do with the suspension then the engine.

On a drag car you want front to back weight transfer to assist in traction on the launch.

On your comment on why the M103 has no knock sensors...
First it had a less then sophisticated EZL control and second it is a 9.1CR motor.
That's why you can run regular with no knocking...
Still not sure why you run regular at the track as it seems counter intuitive.

I know you like to tinker so why not use premium, throw in a bottle of octane booster do a few runs, let the car cool down and pull your R16/1 resistor for a few more runs and compare with your resistor installed runs.

Ed A.

P.S.

Not able to read my EZL P/N as the car is about 20 miles north of me !!!

400Eric · #**281** 09-13-2011, 08:43 AM

I"m having zero traction issues. This thing doesn't make enough low-end torque for me to have traction issues!

I'm running regular for the reasons already stated earlier on this page. IF and when I hear a little detonation, I'll know I'm getting somewhere and I'll switch back to premium.

BTW, that's another rub: MB had no business demanding us to run premium when it clearly wasn't needed in these M103 cars!

I have tried premium and octane booster but since it clearly isn't needed here in this case my experiments have gone in other directions.

As for testing the R16/1 resistor mod, that's still on the to do list. I've been running without the resistors while I do other experiments. Actually, I've been running without the resistors for the last 5 years! On regular fuel now too! It's the first mod I ever did to my M103s! (I don't think I'll ever be able to find them, I'll have to get more at the JY now.) This next track day is slated mostly for trying different CIS-E ECUs that I am running in the car to properly adapt them as we speak so that they will all have a fair chance. My earlier test of the 004 ECU was skewed because I didn't give it ANY adaptation time. I think we are still gonna find that the 008 ECU is still garbage, and that the 002 ECU is still the king, but we have to be sure! BTW, speaking of CIS-E ECUs, could you please also post what number CIS-E ECU your CE has too? Is it also original like your EZL?

Jay, I've thought about upping the resistence value myself, I was meaning to bring that up here but I have other stuff to test at the track first before I turn my attention back to that again.

For the tests to be valid, we can only make one change at a time!

Any chance you'll be able to visit California while you are in the States?
Regards, Eric

JayRash · #**282** 09-13-2011, 09:13 AM

Eric when i used to up the resistance my car used to knock eventually. thats y im sure it does change timing more than what u got on ur ur first try.

as for fuel oct, dont forget fuels have advanced since the m103 days, meaning tech is on our side, and regular fuel is prolly more stable than it was 20 years back. i think

400Eric · #**283** 09-13-2011, 09:16 AM

More consistent at least. Maybe.

RBYCC · #**284** 09-13-2011, 11:21 AM

Quote:

Originally Posted by JayRash

Eric when i used to up the resistance my car used to knock eventually. thats y im sure it does change timing more than what u got on ur ur first try.

as for fuel oct, dont forget fuels have advanced since the m103 days, meaning tech is on our side, and regular fuel is prolly more stable than it was 20 years back. i think

Jay

You are correct about the quality of fuel globally in the early eighties..
Now most fuel in developed countries are considered "tier 1" and contain the necessary additives and detergents that only premium used to have !!

Ed A.

400Eric · #**285** 09-14-2011, 12:25 AM

Ed, at your earliest convenience, could you please post the MB part numbers of your CE's CIS-E ECU and EZL ECU? I'm trying to figure out what a 49 state 88 M103 would have come with originally. I suspect that both of mine on my 88 have been changed.

I thought that you had posted the EZL number for me before but I can't find it anywhere. Maybe I'm mistaken. Maybe I had only asked you if it was original or not and didn't ask what the number was.
Regards, Eric

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode