M119 WOT fuel enrichment questions

[400Eric]

Yea, the C&D article was a 5.6... As for the 2.47 in my car..this is as it came from AMG.. The diff's were what ever you wanted from their selection (2.24 up to 3.27 or there about). My SEL AMG is a 2.82 as is the customers Hammer w/ a 5.6 that's in the shop right now. I have a 93 E420 brain here as an aside :-P Also have an E60 brain but that's in the E60...... You should come out to Atlanta...85 will open up nicely for you from time to time...Was @ a gearing limited 160 in my 560 AMG a few weeks ago...that was Entertaining..esp. for the E46 M3 cab that was trying to keep up and for the 928 that I went by @ over 2X his speed :-P Good Times! Jonathan

Like I said earlier in this thread, you just never know when you are going to NEED that top speed capability! Regards, Eric

[400Eric]

Dave, regarding my mods, I almost forgot, I also removed a screen from the mass air meter. (The one AFTER the wire.) It's something the turbo Volvo guys have been doing to their LH systems for years with good results. Regards, Eric

[400Eric]

I've been surfing around GSXR's excellent site and I've come up with some crazy ideas. (What else is new.) There is a sensor just behind the driver side headlight bucket that tells the LH module the temp of the incoming air. If the air is cool enough, Mr. LH allows a richer mixture than usual. So why couldn't a guy (or gal) do a Jim F. kind of mod and change the value of the resistor at that sensor to fool Mr. LH into thinking the incoming air is cooler than it really is so that he will allow that richer mixture? Maybe even have 2 resistors down there controlled by a switch so a person could have rich when he/she needs it and lean when he/she wants it. I'm also beginning to wonder if WOT mode is really "open loop" after all because of some of the info I'm seeing in the factory manual but I have to do more research on that one. Surely there are guys here who know more info on this. Also the European fuel trimming gizmo looks like a good idea. Anybody try this? I'm willing to be a guinea pig if someone has/or can get one or two. The spot where it's supposed to be probably has a resistor there whose value could also be changed. (This is not to be confused with the "resistor mod" on the older CIS-E cars---that affected ignition advance curves, not fuel enrichment.) I can't help but think that this has all been thought of/done before, we just need the old timers to weigh in and "share the love". Thanks again to all who respond Regards Eric

[cm60k]

Its goog idea Eric,, its worthy to know what well happening with LH with this smart trick......

ZAYED,,

[400Eric]

Thanks! The problem is that we need a guy like Jim F to figure out what the value of the resistor needs to be. Regards, Eric

[gsxr]

1) I'm curious about the mesh screen trick. What exactly is it supposed to do? In general, the screen could "straighten"
turbulent airflow, and it shouldn't cause much if any restriction. I put a new top screen on my MAF last winter.

2) The EZL trim plug is already set to "max power / max advance" on USA models. Nothing to be gained here. I tried
the so-called "resistor" mod on my M103 (1986 300E) after many people on other forums claimed how great it was.
It sucked. No more power, and MPG dropped a solid 10%. The resistor went right back in after 2 trial tanks. Don't
believe everything you read on the internet. ;-)

3) There is a factory tool to tell the IAT sensor that it's 20°C (see photos below). However I'm not sure how the car will
react if the actual air temp is hotter. You could also put your sensor in the refrigerator, and measure the resistance
at ~40°F, for grins. I haven't yet tried the 20°C plug when it's 95°F outside, but I may try that eventually. FWIW, at
the dragstrip, the car does NOT magically go faster as ambient temps drop. I know many other cars do, but the M119
does not. Engine temp and oil temp appear to make a bigger difference than ambient air temp. You can poke through
my dragstrip spreadsheet if you want to look at the data yourself...

[400Eric]

Also the European fuel trimming gizmo looks like a good idea. Anybody try this? I'm willing to be a guinea pig if someone has/or can get one or two. The spot where it's supposed to be probably has a resistor there whose value could also be changed.

Dave, what about the U.S. LH? What was put in place of the European fuel trimming gizmo. The U.S. EZL trim plug may be set to "max power/max advance" but what about the LH? Remember, M.B. was trying to avoid the U.S. gas guzzler tax on the 400E (they succeeded with the 93-on 400E) so it may have had it's fuel "trimmed" a little more severely than the 400Es in other markets. Also remember, M.B. wasn't trying to avoid the guzzler tax on the 500E so it too may have been "trimmed" a little more generously than the 400E.
Regarding the Mass air screens. I mentioned the Volvo guys because I'm actually kind of a closet Volvo guy myself. (I have a 740 gas turbo wagon and a 740 turbo diesel---rear drive Volvos only!) but actually a lot of people are doing it. There is/are a large group of tinkerers who firmly believe the screens restrict flow a little and once the breathing is opened up in the other areas, that "little" restriction becomes a bit more of a bottleneck than it is in a stock situation. Most aftermarket mass air meters don't have them. A lot of people remove both of them for that reason. A lot of people leave the one on the intake side of the mass air meter for the "air straightening" affect/effect but it is apparently not that effective at that task as evidenced by the fact that the screen was replaced by a grid looking thing on the intake side of the meter on the M120 (V-12) eng. ( I just discovered that in your manual).
The testing tool is a good idea but if my math is right, 20 degrees C is 68 degrees F. May not be "cold" enough for much effect. (Please somebody double check my math). I'm going to look into how much it costs though. The refrigerator is a great idea. Got me thinking that the freezer might produce even bigger grins. I think I'll pick up a couple of those sensors at the junkyard to play with since it appears that the ones from the M103, M116, and M117 are all the same as the M119? Right? I also have to figure out why my ohm meter isn't where it is supposed to be and figure out where it is. I can borrow my neighbor's though. Maybe we are on to something! Regards, Eric

[400Eric]

Minor update: I nabbed a couple of those sensors today at the junkyard. While I was there, I saw a later Volvo mass air meter with one of those "grid" looking things in place of the screen on the inlet side of the meter. Definitely looks like it would pose less of a restriction to air flow than a screen would so maybe THAT is why the M120 got a grid instead of a screen. Still no news on the ohm meter front and I haven't seen my nieghbor. They are always on sale at Harbor Freight so maybe I'll go that route (I hate giving more money to China. Did anybody see in this months Motor Trend that a Chinese car co. is the most likely buyer of Volvo? That would give them the safety technology they need so they can sell cars here. Isn't the trade imbalance big enough already?
When are we going to try to reel it in a bit? After they buy GM, Ford, and Chrysler?) (End of rant).
Regards, Eric

[195910]

Most importantly to us. nobody can by Daimler.

[400Eric]

The company that built our 124s was a very different company than the one that exists today. The company started going down hill when Shremp took over. the guy running things now was a loyal Shremp follower.
My concern isn't for GM, Ford, or Chrysler, but rather for the economic well being of every country that isn't China. Regards, Eric

[400Eric]

I nabbed 2 sensors. 1 identical to the one on my car (MB# 009 542 6817) and 1 not (MB#007 542 2117). In mid 90 degree heat the 009s read 1.3k ohms. The 007 read 1.8k. I then "cooked" the 007 (laid it on a black surface in the sun) and got 1.0k. I then froze it and got 5.5k while the sensor end was still wedged between 2 packages of fish (Wild Alaskan Pollack). I went and got a cheap (the good resistors are only at the stores that are closed on Saturdays.) 5.6k resistor that measured a 5.5k. My car's sensor already had a broken retaining tab from my tinkering too much with it so I used it for my mad experiment. I broke off the sensor end and soldered on the 5.5k, plugged it in place and proceeded to rock. The car is a rocket. I know "Butt Dynos" don't hold much sway here but this is too big a gain to dismiss as a "placebo effect". Besides, a gain in torque is much easier to detect via the ole butt dyno than a gain in horsepower is and this car has definitely seen an increase in torque. I fully intend to back my findings with cold hard numbers when time allows. (Anybody near Riverside Ca. that has a performance meter of some sort?) I went to a local "cruise" night (ran into some old friends I hadn't seen in 14 years!) and the car was so quick that I was accused of running nitrous! Also made $100.00! (Please, no lectures. I can't race at OCIR, Carlsbad, or Palmdale anymore because they've all been plowed under.) The thing we need to do now is rig up a way to switch back and forth between the "trick" sensor and the stock one because remember, I only wanted extra fuel during WOT, not all the time. Remember the 007 sensor? since it is a little more generous I'm running it now with good results. I figure the slight increase in fuel will be offset by the fact that we won't be so lean all the time thus putting us too close to the ragged edge of detonation causing Mr. EZL to back off the timing which kills fuel economy. A slightly richer mixture will allow Mr. EZL to allow more timing which should result in better fuel economy. We'll see. If one offsets the other, the economy will stay the same but of course I'll be enjoying the increase in power (however slight it might be. A slight increase is better than no increase). Any ideas about the best way to rig up that switch? Remember, splicing stuff is going to change resistance values and the switch itself probably will too. I know there is a way it's just that I don't know enough about this stuff to do it on my own. Regards, Eric

[400Eric]

BTW, Dave (GSXR) deserves a lot of credit here because he is the one who pointed me in the direction of the freezer. Regards, Eric

[400Eric]

No need to check my math---on page 120 of my 93 owners manual it confirms that 20 degrees C is indeed 68 degrees F. The freezer temp was/is -1 degree F (1 degree below zero F). The 2 "009" sensors were made by BEHR and the "007" was made by Bosch. In the inside cover of my 93 owners manual it says:"Fuel consumption is also increased by driving in cold weather..." which would seem to confirm what the shop manual says about Mr. LH adding fuel (richening the mixture) when the incoming air is cold. I'm not worried about it getting too rich with this mod because we all know that MB wouldn't have allowed these cars to be too rich for too long---only during warm-up in other words. I'm sure many of you know that there are many instances and locations on this planet where the car can be fully warmed-up and is operating for extended periods but is still breathing in air that is only 0 degrees F. That is the condition we are duplicating here. Now I am really anxious to rig up that "switch" But I need input and help. Thanks in advance. I also would like to hear from others who are trying this mod. Regards, Eric

[gsxr]

Neat stuff, Eric! I may have to experiment with this sometime. As for a switch, I would use a factory-type rocker
switch in the ACC or console wood, which would trigger a relay under the hood. The relay would be wired such that
in normal operation, the computer sees the IAT sensor, but when you flip the switch & trigger the relay, the computer
sees whatever value resistor you've installed in the circuit. Might require a DP/DT relay, I haven't sat down to draw out
a schematic or anything, but this should be relatively simple.

I'm going to the dyno on the 24th, I might do two runs with the IAT, and plug in the 20°C (68°F) plug for the last run.
I may not have time to whip up a 0°F setup. At some point I'll try this at the dragstrip too, it would be nice to pull
another 10-15hp out of nowhere for a single run.

New question: Will the computer throw a code when the IAT signal is interrupted, and/or changed radically?

[400Eric]

Neat stuff, Eric! I may have to experiment with this sometime. As for a switch, I would use a factory-type rocker
switch in the ACC or console wood, which would trigger a relay under the hood. The relay would be wired such that
in normal operation, the computer sees the IAT sensor, but when you flip the switch & trigger the relay, the computer
sees whatever value resistor you've installed in the circuit. Might require a DP/DT relay, I haven't sat down to draw out
a schematic or anything, but this should be relatively simple.

Simple for a sharp guy like you, not simple for me. I'll need guidance here.

I'm going to the dyno on the 24th, I might do two runs with the IAT, and plug in the 20°C (68°F) plug for the last run.
I may not have time to whip up a 0°F setup. At some point I'll try this at the dragstrip too, it would be nice to pull
another 10-15hp out of nowhere for a single run.

If I may be so bold, why not do the 0 degree F on the last run---- It only took me 10 mins. to make the thing and that's only because I'm real inept
with a soldering gun.

New question: Will the computer throw a code when the IAT signal is interrupted, and/or changed radically?

I never ran the eng. without it getting a signal from something (either the "109", "107", or the "5.5"). Also only ran the "5.5" after it had already cooled down to below 70 (past 10PM) so I wasn't sending a "0" when it was 95 which might indeed cause Mr. LH to throw a code. We won't know until more people try this. We already know that the computer will ignore info from a sensor sometimes if it thinks the info is bogus. If we do have problems with this issue, we could maybe come up with a resistor to send something like 40 degrees ( the refrigerator instead of the freezer which of course was your original suggestion). Another option is to simply live with it and just clear the code after using the "secret weapon". It's OK as long as the computer isn't ignoring the signal from the "5.5". We'll know if it is or isn't by the performance results.
Regards, Eric




P.S.: Working on a new mod but am going to start a new thread on it since it's not related to fuel.