Actually, I'm asking for my friend Zayed in the UAE who asked me the same question only in a slightly different way and I want to get Jonathan's updated answer on it. It's always good to know all the different ways to break the rules.:P

BTW, our gas here in California is already 10% alcohol.

Always good to hear from you Jay! Regards, Eric

Thnx Eric :)

Now how come u have 10% alcohol in ur fuel man!!!!
well i still haven't added the alcohol as i havent had the time to fit the wide band O2 to the c36, Its still on the poor W124, but i gotta take it off soon before i need a new sensor :P

and yes its always good to learn, my bad on that one.

Many gas stations in the USA are now supplying fuel with 10% ethanol, which allows a higher octane rating, and usually doesn't have much impact on power or economy. I've been using 93 octane for a while now from the local Shell station (remember, USA octane ratings are R+M/2, not the same as in other countries).

Please don't confuse ethanol with methanol... ethanol is fine, methanol is not. Methanol causes all sort of problems with rubber seals & hoses, etc... nothing you'd want in a street car. Ethanol is neat stuff, very safe, non-explosive, you can't even light a puddle of it with a match.

:hat:

On an LH, yes I think it'll throw a code and likely put the computer into some default (and likely lean) map.. I suppose you could play around and find out though :-P

Ethanol..Ugh...Don't get me started on that debacle.. Also, since they started putting ethanol in the fuel full time here I've been replacing EHA seals like it's going out of style.. I used to replace a 1-2 sets of seals a year, now it's the norm.


Jonathan

Jono, I have had zero problems with the ethanol blends on my LH cars, been using them for a few years now. Is it just a CIS problem? I assume that the new EHA seals work ok long-term, it's just the originals that don't like alky, right?

:stuart:

Not sure yet..and yes, I've only had trouble on CIS. I haven't had the new seals in Long enough to be 100% sure, but I'm keeping an eye out:)

jono

Hey guys, are these EHA seals a possible reason why my 88 CIS-E 3.0 300E won't fire? It has spark but it won't fire.

Jay, to answer your question, they put the alcohol (ethanol) in our gas to reduce emissions and to reduce our dependence on foreign oil but there are many who are convinced it does neither. As you can see from the above, there is very little agreement on the stuff. Regards, Eric

Regarding ur EHA, if the seals are done for it should leak fuel. Well atleast thats what i had on the old w124 300TE we had.
Luckily i have had no trouble with my current W124 since ownership back in early 2000 and some 250000km away.

As for the ethanol well it makes ur pump gas into race gas, too bad u cant mix more than 15% of it into ur tank without killing every rubber seal, or hose. and u will need a retune to make use of such a high %.

I used the stuff on my 300 TT thru the Alcohol injection kit, and it did wonders, my friend now has my kit on his bone stock Mitsubishi evo 9 and the car is making over 430hp from a bone stock engine and turbo. but he is at 33% alcohol to fuel, and for sure he has re-flashed his ECU to correct the AFR and up the timing to gain that much power.

I want to try the CTS mod on my 88 M-103 now but it's been sitting too long and now it's giving me a bit of trouble. Maybe some of you know what the problem is? Here's the thread: http://www.peachparts.com/shopforum/tech-help/244582-88-300e-m-103-auto-turns-over-wont-start-post2239365.html#post2239365

Please weigh in with your thoughts. Thanks.
Regards, Eric

Well been playing around with the M104 C36AMG and for the first time i heard incredible amount of knock. I couldn’t believe what I heard, the first time I ripped it up it was in a small tunnel and the sound of this engine is gr8 but something was off. The sound had that familiar knock I used to hear when I first boosted the M103!

I thought this engine had knock sensors, and if you check the engine test logs on the DAS star you will find that the ECU pulls timing per the cylinder that has knock and not just dial the whole map down. SO why on earth then did it knock so hard and so loud. I mean I have test pipes in place of the cats on this car, and its loud, loud enough at least.

Any way this proves that the CTS trick does up the timing significantly :) and thus now I need to install the wide band cause it seems ill need to mix in some alcohol to make use of the trick which will make the car run leaner :( so I need to keep an eye on the AFRs

Maybe you had a bad tank of gas Jay. Some dishonest fuel stations are dispensing "regular" fuel from "premium" pumps. It's been proven time and again here in the states that 25% of the "premium" pumps aren't dispensing premium.

I can't guess why your ECU wasn't able to pull enough timing to compensate.
Regards, Eric

It very much can be, but i do know my gas owner well, and the fuel he uses, but still it can be that.

I think the reason the ecu didnt pull the timing is cause with my trick the ecu reads the water temp at less than 60C' so it just might be that the ecu thinks its a cold start and waits for water temp to rise before it engages full control, like knock and closed loop.

Not sure abt this, just an idea

It turns out I was partially in error on this. The 500E DID get LH in 91 even though the R-129 (500SL) stayed CIS/KE Jetronic and didn't go LH until the 93 M.Y. The 500E was the first Benz to get LH.
Regards, Eric

Hi, I'm new in here. I've messed with CIS for years on VWs and just found this website recently, great stuff BTW. Anyone messed with an adjustable fuel pressure regulator for tuning?

http://shoptalkforums.com/viewtopic.php?f=23&t=114309

You'll almost never see an adjustable pressure regulator on the CIS Mercedes cars. They have a system pressure, a control pressure, and a delivery pressure. Simply raising or lowering the system pressure isn't necessarily going to yield beneficial changes in either the control or delivery pressures. Having said that, I'm not going to say that there isn't any possibility of tuning with CIS pressures. I am going to say that there is a complex relationship between the three that needs to be understood before any meaningful tuning can begin.

an adj fuel pressure reg will do u no good what so ever. if u need more fuel flow for an NA setup, then u need to mess abt with the EHA it has a tiny screw which will result in more or less fuel flow.

if u need to up the system pressure to counter the boost pressure, then u need to know what ur doing and u need a fuel press reader and it is complicated to do.

I saw this post and I think you would be able to help. I have a W124 M103, and it starts fine when cold, but when warm has problems starting, when I check timing with a light it looks a bit retarded (while idling).

Anyways, when the engine is warm and I trick the ECU to think the engine is cold (by connecting the green/red wire from coolant temp sensor to a 10k ohm resistor, which makes it seem as if the engine is -10degree C), then it starts up fine and idles up to 1500, since it thinks its cold.

What could the problem be? It starts fine when tricking the ECU, I'm guessing this is injection side. It is the 2 wire coolant temp sensor.

BTW, I've done all the basic diagnosis and checked fuel pres. and leak down and all have checked within spec.

thanks

OK, I Finally had a chance to take Benzer 1 to the track this past week-end and with NO OTHER CHANGES from the previous time I had Benzer 1 at the track, except for the substitution of the ECU bearing part number 002 545 97 32 and the removal of the resonator and muffler, Benser 1 went a full second quicker in the quarter mile in much worse conditions than what we had the last time we were there! We are talking an uncorrected 15.95 @ 87.27 (15.487 @ 89.939 MPH corrected) where last time we couldn't do better than a 16.95! Mind boggling! We repeatedly spanked a Bimmer 525i in the process too! (Well, actually, slaughtered the Bimmer.) I honestly think that I was more thrilled to get that 15.95 out of Benzer 1 than I was when I got that 14.348 out of Benzer 3!

So now we have some "real world" numbers to back up all of the theories we have discussed here in this thread. It turns out I was on the right track, I just needed to finish the job by freeing up the exhaust and trying that older, Non-California ECU! Sometimes we are just looking in the wrong places! We have to take care of the basics first. Now this car might be more responsive to some of the other tricks discussed here in this thread!
Regards, Eric

ECU bearing? Please tell us more! Or did you remove them muffler bearings and install them on the ECU...? (sorry, I couldn't resist, lol...)

:stuart: :stuart:

fresh headlight fluid makes an extra 20HP last I read on the interwebs!

Congrats Eric:)

Yeah, and adding a wing on the back will reduce your E/T by a half second!
Regards, Eric

The thought occurs that if you want to try tuning the CIS the best start would be a junk yard for an EHA valve thing. Then you can adjust and fiddle with it to your heart's content, knowing that your factory-set one is safe there ready to refit if you screw everything up :)

The very next thing that I'm gonna try is my dummy CTS trick. It did provide me a documented, repeatable gain at the track with my M119 and I fully expect it to do the same for my M103 since CIS-E M103s are even easier to fool than LH M119s are. The neat thing about the CTS trick is that it also gives you additional ignition timing and is by far the quickest, cleanest, easiest mod of them all to do and undo! Just unplug the plug from the stock one and plug in the dummy! When you leave the track, do the reverse! I've obtained TWO EHAs from the P-n-P but I'm hesitant to mess with the EHA on the car because I don't want to jeopardize my street fuel economy. My dummy CTS mod allows me to switch back to "street mode" far easier than switching out EHAs would.
Regards, Eric

Well, first of all, I've been doing you all a disservice by referring to my dummy CTS mod as the dummy CTS mod when I should have been calling it my dummy ECT mod. (The CTS is the one that tells the cooling fans and temp gauge what the engine temp is while the ECT is the one that tells the ECU what the engine temp is.) While I'm confident that most of you still knew what I really meant, I still need to be more accurate, especially because some of the newer members of this board may not know the difference.

Well, the results this time were a wash. No gain. (No loss either.) I don't know if it's because the ECT that I used was actually from an M119 car (It is in fact the very same exact one that I used when I tried this mod on my M119. I thought they were the same!), or if it's because I couldn't put the dummy ECT in a location where it could stay as cool as I was able to do on the M119 (the ECT is on the back of the M103 while it is on the front of the M119), or if it was something else. Who knows. There is no doubt though that since this mod did work so well before (as documented in back to back testing at the track on my M119), that it would work well on this car too since, again, M103 CIS-E cars are easier to fool than M119 LH cars are. (If only I could figure out what the problem is.) I would like to have this mod as an option because I really do love to have that "plug and play" ability.
Regards, Eric

I suspect that the fuel & ignition maps on the M119 LH and EZL do not vary the mixture/spark as much as the CIS-E does, given different inputs. It's not that the M119 is harder to fool, it's that the M119 doesn't reduce output as much during "less than optimal" conditions.

FYI, the FSM (more specifically, the Diagnostic Manual) specifies that when dyno testing the M119 engine, a fixed IAT of 20°C and fixed CTS of 80°C should be installed. I've tried 60°C vs 80°C and found basically zero difference in power output between those two points.

:detective:

Now you are making the same mistake I was. When you said "CTS" you meant "ETC", correct?

The pre-90 CIS-E cars didn't have IATs so that isn't an option for manipulating and fooling the ECU/EZL in my case.

Dave, are the ETCs the same between the 2 systems? I know for a fact that the IATs are different between the post-90 CIS-E cars and the M119 cars, with different part numbers, and slightly different behaviors (Remember? In my thread my tests showed the IAT from the CIS-E cars is more "rangy".) even though they physically interchange. I'm now wondering if the ETCs might be different between the 2 systems too.
Regards, Eric

The four pin CTS / ECT (not ETC) is the same on all LH cars, but I'm not sure if it's used on any CIS models. And you are right (again!), the official MB acronym is ECT - resistance data (for M119 ECT sensor) is here:

http://www.w124performance.com/docs/mb/M119/LH_temp_sensor_values.pdf

If that doc is to be believed, it says that yes it's for both CFI (CIS) and LH, including M103/M104. Then again it says the IAT values are the same and you found they were not, so... all bets are off again...

:stuart:

Yeah, just one post earlier I was calling it by it's correct name, ECT.
How and why did I suddenly start calling it ETC? :o:confused:

The reason why I am thinking the CIS-E cars use a different ECT is because the plug in the harness on my 300E has a flat spot in it to line up with a corresponding flat spot inside the ECT so that they will go together only one correct way. The ECT I pulled from the JY M119 doesn't have that flat spot leading me to suspect that the CIS-E cars used a different ECT. (I was forced to line up pin numbers to insure that I installed it correctly. Maybe I messed up and that explains why I got no gain this time? Maybe the #"1" pin on the M119 ECT isn't the same as the #"1" pin on a M103 ECT is?) I of course didn't know about these issues until I was at the track and unplugged my M103's ECT for the first time. The part number on this JY M119 CTS is 008 542 32 17 BTW. I can't see what the number is on my M103 ECT without removing it.

Regarding the IATs, the part number for the one for CIS-E cars starts with a "007" and the one for the LH cars starts with a "009". I can't remember what the HFM M104s use though.
Regards, Eric

OK, I've just read all 12 pages of this thread again and I'm still not clear about how to substitute the 1,200 ohm resistor in place of the ECT sensor to bump only the timing, not the fuel. I understand that 2 of the wires from the ECT are for the CIS ECU and the other 2 wires are for the EZL, but which ones are which? I read the post were Jay says to just do a continuity test but my multi-meter is missing again. Besides I'm thinking that since Jay has already done this mod to a M103 car, he can just tell me which wires to solder the resistor to! Come-on Jay, help me out! We've got another track day coming up in a few days and I'm ready to try your mod at the track!! Some pictures would be really helpful too! Please help!
Regards, Eric

I too would also like a better picture of what this looks like. :):D:cool:

Guys, unfortunately the M103 that had this mod done too Deema has hadd its wiring harness replaced. Any way i have to tell u that u need to do a continuity test, last time i did this trick on the M103 was 10 years ago TEN guys. i know i have a good mem but i swear i cant recall the wires. But ill try and look at my M103s today and see what i can offer..

stay tuned.

OK, I finally found my multimeter, was able to do the continuity test, and install a 1,200 ohm resistor. It's installed so that it's resistance is provided in addition to the resistance provided by the ECT sensor, not in place of it. We'll see tomorrow what happens.
Regards, Eric

Eric is the ect in the m103 with 2 wires or 4. If 2 wires what color is the wire and u did the check to the Ezl right?? On my 87 4matic it has a 2 wire ect.

There's a 4 wire that has 1 wire to signal the CIS, 1 wire to signal the EZL, and 2 grounds.There's also a 2 wire sensor that signals the cooling fan when to come on. These are just like what you'll find on your M119 too. The 2 wire sensor is the one we put the resistor on to make the fan (fans on 90 and later W124s) come on sooner rather than letting the engine get so hot before the fan finally comes on. http://www.k6jrf.com/MB_CTS.html

I wasn't too thrilled about blindly, randomly, putting electrical juice into sockets that I had no idea about where it would be going to so I dug out my (British market only) Haynes W124 manual and studied the wiring diagram which gave me a fairly good idea of which socket to try on the ECT sensor plug and which socket (and in which plug) to try for the EZL. Got it right on the first try. It's best to always do a little research and investigation first before you start sticking your probe into unknown holes! In other words, know the hole first! ;):cool::P:D

It was getting fairly dark by the time I finally started soldering so I can't tell you the color of the wire. It looked pretty dark though in the funky, blueish light of the LED flashlight I was using. More importantly though, I can tell you that it is socket number "1" in the ECT plug and also socket number "1" on the EZL plug. (It's not very often that something works out that simply!)
Regards, Eric

Socket 1 is the one congrats man. i hope u see the difference :)

Why couldn't you have just told me that last night when I asked? (Instead of saying: "That was TEN years ago, I don't remember.") Could have saved me A LOT of time!

Don't be upset erric pls. I had to wait for my sis to come back so late at night and went out and checked the wires. I'm sorry man. At least u got it right and u know how u got there.
If u think I didn't wanna help u trust me ur mistaken. And I swear it was ten years man. Other than that I am under extreme stress these past weeks. New job that has a vertical learning curve. AMG involved in an accident and it's costing me a fortune to fix it :/ and I'm not sleeping much:/. Trust me look up F.U.B.A.R. That's me :P

No, I'm not upset. I was just perplexed, that's all. ;)

That's the trouble with the printed word. It's too easy to mistake the intent of the author. :)

Just remember the advice I gave you: Know the hole BEFORE you probe it!
Regards, Eric

Lol I used to know those cars inside out man. I still do but I never had the book u mentioned. But to my advantage those cars a pretty fool proof. :P.
I'm thinking of doin the trick on the m119 and see what power the v8 has hidden in it.

Just be careful cause, as we have already found out and has already been discussed earlier in this thread, it's harder to fool the EZL on the LH cars without the LH finding out and it will likely make you too rich all of the time, even under part throttle cruise conditions when you don't want to be rich.
Regards, Eric

Na I always fit a shorting wire setup parallel to my resistor. That way I switch it out when I don't want it.

Well, please let us know how it works out as I'm still looking for a way to increase the timing on my 2 M119s! And please post pictures this time!
Regards, Eric

Eric if u switch to the later ecu that has no enrichment and then use the trick and even if u run more rich it can be a way to get the best of the 2 worlds. any way I'll give it a try soon and see how it goes. I can't promise a time line thou.

Eric my m119 has the 4 wire ect expected now that has 2 white wires which logically should be the ground. The other 2 are a light green and some darker blue color or something that I couldnt make out. Any way does it show in ur book anything abt wire colors. ? Prob is my ect harness plug is too broken up for me to try and unplug it on a weekend.

Thanx any way

That's the super F'ed thing about this book..... it doesn't cover the M119 powered W124s. Why did I buy it? Because at that time there weren't ANY W124 manuals available here in the states except for the nearly unobtainable factory one. Now though the factory W124 manual is all over the place on the web. GSXR has it on his site, his was one of the first sites to have it. Just hit the link in his sig.

Remember I tried it that way back before I had an enrichment ECU. I did see a gain with my "dummy" ECT sensor and I documented those gains earlier here in this very thread. But I still did better with an enrichment ECU once I got one.

I'm posting the above post from my drag racing thread to re-document what Benzer1's best 1/4 mile E/T and MPH performance is so far. This time at the track our best uncorrected E/T was a 16.13 @ 86.56 which corrected to a 15.732 @ 88.802. Our best corrected E/T of the day was a 15.712 @ 89.619. The car is unchanged from when it ran that 15.95 except for the ECT mod, a cleaner air filter, and a firmer shifting trans (from the "T" bar being turned tighter). So this ECT mod isn't looking too good at the moment. I'm not ready to give up on it though. I'm thinking that the problem is that 1,200 ohms just isn't nearly enough to make a significant enough difference in the amount of additional advance being given to the engine for it to show up as better E/Ts. My manual says that the ohm value for the ECt when it is at 0 degrees C (32 F) is 6000 ohms. I hate to fall for the "more is always better" routine but that may be exactly what is needed in this case. I'm thinking to bump the resistance level up to 2,200. What do you all think?
Regards, Eric

I dunno Man, on my M103 i ran at abt 1.6 max. the car always felt better with the resistor. To the point that when i changed the harness and as such removed the trick my sister noted that the car had lost some low down pull. any way all i can say is that i dynoed my car and engine power was rated on the Bosch dyno at 205 or something close to that at the flywheel.

the reason i fit a variable resistor is because u might need to make several changes. BTW i do believe certain EZLs have already more timing in them. depending on the make year.

do try the 2200 thou
it might do just fine

Pardon me with a 1.5 k on my m104 I get knock,so I run a 1k.I want to try 1.3k as soon as I find one.The rattel (not really a knock) is on light pedal.

M103 runs 9.2 comp vers 10 in M104. M103 has no cam advance in mid rpm range thus runs lower dynamic compression in that range. Thats y in M103 u can go more with timing. but also do keep in mind that ezl and M104 ecu are already mapped differently and as such we cant even comp the 2.

As i told u Nate , knock will be on part loads in mid range. its the cam advance that gets us there.

An increase in low end torque is what I was/am after with this mod but the 60' times don't reflect a gain there. Our best 60' this time was a 2.572 even though Benzer1 has gotten some 2.4xs on previous dates. It just seems like the timing advance hasn't been increased enough if any at all to make a significant enough difference to show up on the time slips. I guess I need to advance it enough to hear some pinging and then back it a bit back off from that to know where I should be, then take it back to the track. I don't think I'm being unreasonable to expect a 2.3x 60" from the increase in low end torque that a generous amount of timing advance should be netting me.
Regards, Eric