Tuning with CIS - Page 2 - PeachParts Mercedes-Benz Forum

RBYCC · #1 03-03-2009, 12:13 PM

Quote:

Originally Posted by JayRash

well in theory it should, just need to tap into the correct wiring. but the diff is in the autotech the device reads the plate voltage and thus determines when to activate.

but don't think its doin anything to the timing side of things. more timing will really give good mid range pull.

The only thing the Autotech does is increase fuel delivery at wide open throttle position via the EHA.
It does so without tampering with any stock settings which is important.

I know of no single device that controls timing and fuel as these are in essence two discrete systems on the KE-Jetronic III equipped vehicles.

To modify fuel delivery at a point other then WOT on a stock engine would really not accomplish much.

Pulling more timing advance would give a better low end response.

JayRash · #2 03-03-2009, 12:26 PM

i know timing is another ECU the way to work with it is to fool its temp based mapping and timing will be altered enough to feel the diff. i mean more timing than pulling the resistor could do alone

400Eric · #3 03-05-2009, 05:28 AM

I have an 88 M-103, an 89 M-103, and a 93 M-119. I believe the M-119 would benefit from this mod as well and stated so at the end of last year in post #39 of this thread: E500 W124 performance mods
In that post I stated, in part: "Also have done the Jim F "Cool Harness" mod but that had zero effect on my better runs cuz you've got to be at 80 degrees C or less to get a good time and the Jim F mod doesn't kick the fans on till well after that temperature. I guess a guy could run a higher value resistor to get the fans to keep the temp at 80C but I would rather run a second resistor at the other temp sensor to fool the ECU and EZL into thinking it's 80C all the time so that they will allow full "Party Time" mode all the time."
I think even 80c may be too high. There may be more to be gained by going for 40c or 60c. So today I picked up three 4 pin temp sensors at the local U-pull-it and I'm going back to the track this Sat. Since the sensor is grounded through it's wires and not it's case, I can just plug in a "dummy" sensor, wrap it in a bag, and leave it on top of the eng. Since the business end won't be submerged in water, it will automatically read lower---just what we want. And the gauge will be telling me what temp. the sensor is telling the EZL and LH ECU. I can move the sensor around a little to fine tune the final temp. I will report here, at that other thread, and on a new thread the results. Regards, Eric

gsxr · #4 03-08-2009, 11:24 AM

Quote:

Originally Posted by 400Eric

I have an 88 M-103, an 89 M-103, and a 93 M-119. I believe the M-119 would benefit from this mod as well and stated so at the end of last year in post #39 of this thread: E500 W124 performance mods
So today I picked up three 4 pin temp sensors at the local U-pull-it and I'm going back to the track this Sat. Since the sensor is grounded through it's wires and not it's case, I can just plug in a "dummy" sensor, wrap it in a bag, and leave it on top of the eng. Since the business end won't be submerged in water, it will automatically read lower---just what we want. And the gauge will be telling me what temp. the sensor is telling the EZL and LH ECU.

Eric, that's a great idea, adding a "dummy" coolant temp sensor that's loose under the hood. One catch - the dash gauge reads from a totally different sensor. So you will never know what the "dummy" sensor is reading, without a digital scanner connected (which will show you the live data from the dummy sensor). That's good though, this way you know the exact engine temp based on the dash gauge.

Regardless, it should still work pretty well - and your tests back that up. I was going to try this myself, with a resistor pack, but I like your idea better since it's easier! Now I just need a 4-pin sensor...

400Eric · #5 03-08-2009, 11:27 PM

Quote:

Originally Posted by gsxr

Eric, that's a great idea, adding a "dummy" coolant temp sensor that's loose under the hood. One catch - the dash gauge reads from a totally different sensor. So you will never know what the "dummy" sensor is reading, without a digital scanner connected (which will show you the live data from the dummy sensor). That's good though, this way you know the exact engine temp based on the dash gauge.

Regardless, it should still work pretty well - and your tests back that up. I was going to try this myself, with a resistor pack, but I like your idea better since it's easier! Now I just need a 4-pin sensor...

You know, it's a funny thing, I left the dummy sensor on today---just for grins---Went to church, also went to a couple of stores, and I keep wondering why the gauge was reading so high. So we have one sensor for the fans, one for the LH and EZL, and a third one too? Where is it? This means I didn't really know what temp. was being sent to the LH and EZL?

What I'd like to do on the street is let the LH see actual eng. temp. (for good fuel economy) and let the EZL see only what I want it to see via a resistor (which should help both fuel economy and power---the EZL is way too prone to pull ign. advance at the slightest little rise in temp). I just don't know which pins go where.

I can't wait till you start trying this stuff on your E420. Just make sure you've got plenty of rubber under that thing! Regards, Eric

gsxr · #6 03-09-2009, 03:47 PM

Quote:

Originally Posted by 400Eric

You know, it's a funny thing, I left the dummy sensor on today---just for grins---Went to church, also went to a couple of stores, and I keep wondering why the gauge was reading so high. So we have one sensor for the fans, one for the LH and EZL, and a third one too? Where is it?

It's right next to the other sensors. 4-pin is for LH+EZL, 2-pin is for the fans, and the 1-pin connector is for the dash gauge.

Quote:

Originally Posted by 400Eric

This means I didn't really know what temp. was being sent to the LH and EZL?

Bingo! Only a digital scanner will show you that.

Quote:

Originally Posted by 400Eric

What I'd like to do on the street is let the LH see actual eng. temp. (for good fuel economy) and let the EZL see only what I want it to see via a resistor (which should help both fuel economy and power---the EZL is way too prone to pull ign. advance at the slightest little rise in temp). I just don't know which pins go where.

Can't do it. The LH injection systems have logic built in to compare the two values. If they are significantly different, the computers assume a faulty sensor, and will use the higher of the two values. This is mentioned in the factory documentation somewhere (I just read this within the last few weeks).

JayRash · #7 03-05-2009, 05:43 AM

Eric,
Try and have the engine think its at 40c, on your car it will fool both injection and ignition together, but i suppose you will be running too rich. and thats what makes this modd better on the W124, since u can fool timing and injection seperatly.

Any way we tried this on a C36 and did give that car better response, thou i really didn't get to try that car enough to have more accurate data.
The limit was that it would start running too rich and thus loosing the gained performance way before reaching the timing limits.

any way just fit a variable resistor and look for that sweet spot.

looking forward to your update.

Opps, does the 400E control timing thru a similar EZL like w124s!!!! or is it like the C36 M104?? would be gr8 if its an ezl i guess.

mixmazz · #8 12-13-2010, 01:22 PM

Quote:

Originally Posted by JayRash

Eric,
Try and have the engine think its at 40c, on your car it will fool both injection and ignition together, but i suppose you will be running too rich. and thats what makes this modd better on the W124, since u can fool timing and injection seperatly.

Any way we tried this on a C36 and did give that car better response, thou i really didn't get to try that car enough to have more accurate data.
The limit was that it would start running too rich and thus loosing the gained performance way before reaching the timing limits.

any way just fit a variable resistor and look for that sweet spot.

looking forward to your update.

Opps, does the 400E control timing thru a similar EZL like w124s!!!! or is it like the C36 M104?? would be gr8 if its an ezl i guess.

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

400Eric · #9 03-05-2009, 07:29 PM

If you meant similar to the M-103 EZL then yes, it is. (All 3 of my Benzes are W-124s.) I'm not worried about going too rich as I've done breathing improvements that need to be compensated for anyway and both of the LH ECUs I'm running are 93s and therefore lack WOT fuel enrichment. If it gets too rich I can always up the temp. back to 60c or 80c. I saw an over 3 tenths improvement in the quarter mile just from dropping the eng. temp. from approx. 90c to 80c. I also have a traction problem at 80c that I don't have at 90c. (This is a non-ASR car.) Regards, Eric

JayRash · #10 03-06-2009, 01:45 AM

Quote:

Originally Posted by 400Eric

If you meant similar to the M-103 EZL then yes, it is. (All 3 of my Benzes are W-124s.) I'm not worried about going too rich as I've done breathing improvements that need to be compensated for anyway and both of the LH ECUs I'm running are 93s and therefore lack WOT fuel enrichment. If it gets too rich I can always up the temp. back to 60c or 80c. I saw an over 3 tenths improvement in the quarter mile just from dropping the eng. temp. from approx. 90c to 80c. I also have a traction problem at 80c that I don't have at 90c. (This is a non-ASR car.) Regards, Eric

Thanx for the proof that this somewhat free HP trick does work.

400Eric · #11 03-08-2009, 03:40 AM

Well what can I say--- the car needs bigger tires now.

14.72@95.51 vs. previous best of 14.959@93.81. (14.44@97.405 MPH vs. 14.593@96.219 corrected) This day was 9 degrees F. cooler so I corrected the times http://www.dragtimes.com/da-density-altitude-calculator.php?elevationcorrect=1696&et=14.72&mph=95.51&correctetmph=Correct+ET+and+MPH and as you can see, there still is a nice gain. The gain could have been even more but when I drop the temp below aprox. 70c the car makes so much low-end torque that I lose traction, have to feather the throttle, and wind up running 15s (if I'm lucky). I have a hard enough time hooking up at 80c! I'm not going to start a new M-119 based thread on this mod like I planned until I can upgrade my rims and tires so that the full benefit of this mod can be properly documented. (I'm going to wear out my current tires first). I am going to try to get a friend to scan the timeslip and post it. Regards, Eric

gsxr · #12 03-08-2009, 11:30 AM

Quote:

Originally Posted by 400Eric

...when I drop the temp below aprox. 70c the car makes so much low-end torque that I lose traction, have to feather the throttle, and wind up running 15s (if I'm lucky). I have a hard enough time hooking up at 80c!

Eric, assuming you have stock wheels & tires mounted, what tire pressure were you running at the dragstrip? With traction problems, I would try lowering the pressure down to the low 20's (I wouldn't go below 20psi (cool/warm) on street tires though). That may help you hook it up. You may also need to start doing a burnout prior to launch, just in front of the waterbox (or are you already doing that?). You generally want to stay out of the waterbox with street tires since the tread will pick up some water and carry it up to the starting line.

400Eric · #13 03-09-2009, 12:58 AM

Quote:

Originally Posted by gsxr

Eric, assuming you have stock wheels & tires mounted, what tire pressure were you running at the dragstrip? With traction problems, I would try lowering the pressure down to the low 20's (I wouldn't go below 20psi (cool/warm) on street tires though). That may help you hook it up. You may also need to start doing a burnout prior to launch, just in front of the waterbox (or are you already doing that?). You generally want to stay out of the waterbox with street tires since the tread will pick up some water and carry it up to the starting line.

205/60 15s at 35psi. As for the rest of your post, I already know those things and act accordingly---I used to race a lot back in the day at Carlsbad and OCIR---always on street tires---I always want to know what my cars run in the real world---on street tires with street gas, no ice on the intake etc. (I think we talked about that before.) In my experience, tire deflation isn't that effective on street tires---that is actually more for the slick running guys. Muscle Mustangs and Fast Fords did a story about 10 years ago that backs me on this.
The problem here is that these tires are just too small. Who else is running tires this small? Nobody at that dragstrip yesterday had tires this small. I actually already have the new tires--205/55 16s-- the Goodyears that won the C&D shoot-out not too long ago, But I need 2 more rims. I'm looking for 2 front S-class (W-140) rims---the ones that look like mine only they are 16s not 15s. Are these the rims the 500E/E500 got? And why the "Front only" "Rear only" thing? Do we have to adhere to that when using them on an E class? Regards, Eric

JayRash · #14 03-08-2009, 06:56 AM

so erric, i bet with no cats, the car should be close to abt 300 hp all in all. dunno just throwing a number here. but would be nice if you drop the temp more and dyno run the car.

Cool thing is that on a g-tech i clocked 1/4 mile in 14sec @102mph. but that was before i upped the boost and installed the meth kit.
Last time i timed my car 0 to 100 mph it clocked 12.1 sec

400Eric · #15 03-08-2009, 07:30 AM

I figure I'm at 305hp even with the stock cats. Remember, I'm running a uncorrected 14.72 vs. the corrected 15.3 Car and Driver got from a stock 93 like mine back in 93 and it is rated at 275hp stock. And I'm still running those rotten 2.24 gears in the back! The commonly accepted rule of thumb is 10hp for every .10th reduction in ET. That should equate to a three tenths reduction and I'm already at twice that. Regards, Eric