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WOT-Enrichment on 4.2L M119 - Pt. Numbers for LH Modules

Christian_K

I do believe...!
Member
Hi, was there a WOT enrichment on the E420 or not? We have this discussion around german Forums for years now and yesterday it started all over again. People claim it was only available in US since the 400E was introduced earlier into the US.... Howerver:
Fact is in the WIS there is not a single word about it. Another fact is that in Germany early 1992 400E Models were rated at 286HP(DIN) while later ones (near end of 1992) got only 279HP(DIN) even though the compression has been raised from 10:1 to 11:1. Whats up with that? Does this makes any sense?
Where to find any "true" data about that? Since years no-one seems to able to answer this issue a 100% correct.

Also what is the powergain when installing a WOT-enriching LH-Module in a 11:1 compression car? I've read that Eric and/or Dave have tested this on a racetrack an have had noticeable results.
I also have found this statement by Dave in the Benzworld.org Forums:
"I have one in my '95 E420 and it works great. Picked up a full 2 tenths and 2mph at the dragstrip with no other changes compared to the stock module. On the dyno it translated to approx 290hp at the crank, compared to 275hp stock. I can email you the dyno graph if you're interested.
"
Can i see this diagramm too?

And can someone post the part-Numbers for the Modules with WOT-enrichment if there was any at all.

Best Regards, Christian
 
They do indeed exist. See attached dyno graphs. The factory power ratings make no sense, as the '92 engine was rated at lower power than the 93-95 here in the USA. I really believe there are multiple typos in the factory docs related to the 4.2L power numbers, but I can't prove anything. I just know how my '95 E420 performs with the '92 LH module installed. Don't forget to reset adaptation when installing a new module.

400Eric also found that the '92 EZL was worth some additional power, but it may not work with E420's after VIN B965056; i.e. I think the 013- EZL may only replace the 014- EZL. When I tried an 013- EZL in my car with the 015- EZL, it wouldn't run, and the 013- EZL was good. Note that while all the 5.0L EZL's are interchangeable (they all supercede to the current p/n), the 4.2L EZL's are not interchangeable according to the EPC. I'm not sure why.


:e500launch:
 

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Very nice, thanks!
I think the EZLs are different because the ignition angles have been changed according to my data and the german typical stickers in front of the M119 engine.
For the early 400Es with 10:1 compression ratio it was 41°-46° at 2500RPM while car is not moving, for the 11:1 compression cars it was retarded a bit to 38°-45° according to stickers.

So actually when i'm thinking about it, when you take a 11:1 E420 of the latest ones, plug-in a early EZL with more advanced ignition-angles, change LH into the one with WOT-enrichment and using a premium high-octane fuel, it should be the best power that is possible on the E420 without any severe changes.

Ohh and btw, another myth was busted by a german user with a E420. He tested Lambda-Signals live on Autobahn at top-speed with the stock ECU and with the infamous Ebay Chip.
Now guess what, contrary to the belief that a ECU Chip can NOT restore WOT-Enrichment, it actually does exactly that. That guy in German Forums said, that at full speed at Autobahn and Full-throttle with stock ECU, the O2-Signal was still fluctuating roughly every second, but after installing the Ebay ECU Chip for 55$, it goes to super-rich as soon as you Floor it and Lambda will not fluctuate anymore, it remains in the "rich" area. :-)
 
Christian_K said:
Ohh and btw, another myth was busted by a german user with a E420. He tested Lambda-Signals live on Autobahn at top-speed with the stock ECU and with the infamous Ebay Chip. Now guess what, contrary to the belief that a ECU Chip can NOT restore WOT-Enrichment, it actually does exactly that. That guy in German Forums said, that at full speed at Autobahn and Full-throttle with stock ECU, the O2-Signal was still fluctuating roughly every second, but after installing the Ebay ECU Chip for 55$, it goes to super-rich as soon as you Floor it and Lambda will not fluctuate anymore, it remains in the "rich" area. :-)
Interesting! What part number LH module does he have, and what year/model did he specify when ordering the eBay chip? A wideband O2 is really needed to determine if the mixture is correct, as I've seen dyno graphs with the eBay chip showing the mixture going too rich (approx 11.5 : 1) which actually reduced power compared to the stock '92 chip (which kept the WOT mixture at 12.5 : 1).

I know the late chips (93-95) are not compatible with the early LH modules (92) but I had not yet tried the reverse scenario.


:detective:
 
Hi,

After replacing my MAS my values went back to normal, 23Kg./Hr., Still the rough idle it use to have is gone, but I am feeling a slight miss, which may have also been there before but was not noticeable due to the really bad rough idle caused by the bad MAS (34Kg/Hr). Plugs, rotors and caps are new, Bosch spark plugs made the car run good for a day or two but the miss is back, slightly there but its there. Since I am getting the re-occurring DTC on PIN 17 >> 5, PIN 19 >> 25.

Both codes show up at the same time, Since I am still restricted "at times" to 4200 rpm, I believe I will jump into replacing the EZL, feels more of an ignition issue. I noticed my car has one with the part No. 015-545-6132, and I don't think its the original one since the EPC points to 6032 and 6132 upto 92 model. I found some that look decent on ebay with the last four numbers ending in 4532, 6332 and a 6032 that does look so promising. Are there any particular differences I should be aware of and stir clear of..?

I am not sure if these would cause conflict with my LH module..?

Thank you guys,
 
Benzer said:
Both codes show up at the same time, Since I am still restricted "at times" to 4200 rpm, I believe I will jump into replacing the EZL, feels more of an ignition issue. I noticed my car has one with the part No. 015-545-6132, and I don't think its the original one since the EPC points to 6032 and 6132 upto 92 model. I found some that look decent on ebay with the last four numbers ending in 4532, 6332 and a 6032 that does look so promising. Are there any particular differences I should be aware of and stir clear of..?
Your 1995 E420 should have an EZL p/n 015-545-60-32. If you have an 015-545-61-32, that is for a 5.0L engine!! That might be part of your problem! :D Note that the 4.2L modules are completely different part numbers than the 5.0L and they should not be interchanged.

I would not use anything except the correct part number... while all the 5.0 EZL modules are interchangable (on 5.0L engines), the 4.2L modules may not be (even on 4.2L engines). I have been able to run both my 5.0L cars on all four different 5.0L EZL's, but my '95 E420 (with 015- original EZL) refuses to run with the 013- or 014- EZL. I'm not sure what the difference is but I do recall that it would throw some odd codes when the wrong EZL was installed, the tach would jump all over, and it would barely idle let alone drive. I never would have thought to check for a wrong EZL in your car, but sheesh, it sure looks like that is a strong possibility....!!!!

:blink:
 
Holy s***, Yes the EZL in my car does end in 6132. I noticed that the same day I cross-checked the FPR and the p/n did not add up as well!!

I know this was a 1 owner, (local), car for 100K, then it passed through 2 more locals. Tracing back some timelines I believe one drove it for 10K and the other for 20K until I rescued it.. I would like to get my hands on the mech.. who is responsible for all these pull-a-part rigs,..my God!! Since the EZL is for the 5.0, I makes a whole lotta sense why the car lags in acceleration, and acts up all over the place!! The EZL is processing ALL the info. correctly but its output will never be optimized, most likely that is why the oscilloscope read OK, but it doesn't apply to this particular vehicle.. Regardless, no sense in my still throwing more parts at it, if had the wrong Brain transplanted.. So I will begin a careful search for one now. Makes sense, if it is throwing the wrong numbers the ignition is off right at the point where the torque curve begins to spike up, around 4K rpm, so there must be some pinging or knocking going on, triggering the KS CEL, (I am still weary that they may be damaged to some extent though but this would not have to hamper the cars high end range). So I must get DTC 5 on PIN 17, due to the EZL mismatching information with the LH and the DTC 25 on PIN 19 caused by some knocking due all this commotion going on... Crap, I hope my new caps and rotors are not shot by now..

Note, the car WILL drive without these codes popping up for days, it is not until I try to push the car over 4K..!! Then after 5 or 6 times, the CEL pops on..So I am going to drive "real cool" until I get that part in...

Correct me if I am wrong please, but from what I can understand by know on some reading I have completed is the following:

The EZL module controls the injectors and compares two sinewave's from the Camshaft Positioning Sensors. It also communicates with the cam adjusters. Based on the information gathered from the positioning sensors, the vacuum/load from the manifold and what goes back and forth from the LH-SFI it will send data to the cam adjusters to either increase/advance or decrease/retard the CAM. This will ensure the correct amount of torque/speed depending on how hard you floor it, ie 'load'.

Does sound close to the functions in a nutshell..? It is a good starting point...


Thanks, guys, Dave..!!
 
They do indeed exist. See attached dyno graphs. The factory power ratings make no sense, as the '92 engine was rated at lower power than the 93-95 here in the USA. I really believe there are multiple typos in the factory docs related to the 4.2L power numbers, but I can't prove anything. I just know how my '95 E420 performs with the '92 LH module installed. Don't forget to reset adaptation when installing a new module.

400Eric also found that the '92 EZL was worth some additional power, but it may not work with E420's after VIN B965056; i.e. I think the 013- EZL may only replace the 014- EZL. When I tried an 013- EZL in my car with the 015- EZL, it wouldn't run, and the 013- EZL was good. Note that while all the 5.0L EZL's are interchangeable (they all supercede to the current p/n), the 4.2L EZL's are not interchangeable according to the EPC. I'm not sure why.


:e500launch:

Dave, it's been 9 years since your post. Is it still a current knowledge that 013 EZL wont work on a car that came with a 015 part from the factory? If so, do still not know why?
 
Dave, it's been 9 years since your post. Is it still a current knowledge that 013 EZL wont work on a car that came with a 015 part from the factory? If so, do still not know why?
From what I can tell, a 4.2L, 013- EZL may work in a 94-95 E420, with certain LH modules... maybe. Someone tried this not long ago and reported that it worked, and they had been driving like that for a while. Can't recall the year in question, could have been a 1993? I forget what LH module they had, might have been a 1992 LH matched with the 013- EZL. Might have been @northNH?

My notes indicate I tried a quick test of a 92 400E LH module, with 92 400E 013-63 EZL, in a 1995 E420... and the engine started & ran OK without any codes - just a slight idle oscillation. I plan to try driving a car with this setup eventually but haven't had time.

I still do not know the technical reason why some EZL's do not work with certain engines and/or LH modules. I suspect there is a difference for open-deck blocks, but that's all I can come up with, and it still leaves a lot of questions.

:scratchchin:
 
What would you expect from swapping in a ‘92 EZL into a ‘94 420 that was already running well with a ‘92 ECU?
Anything worthwhile?

TIA


@400Eric did this years ago, and found that a 1992 EZL (013- part number) installed in a 1993 400E (replacing an 014- part number) provided a pretty substantial improvement in performance, as measured at the dragstrip.

HOWEVER, the 4.2L EZL's are not all interchangeable like they are on the 5.0L engines, there is an engine number break, possibly related to the change between closed deck and open deck (not sure). Based on my experiments, I found certain combinations of EZL and LH part numbers don't work in a 4.2L with 11:1 compression ratio. That said, I think if both a 92 400E LH and EZL are used together, they MIGHT play nice together in a 94-95 E420... but I haven't driven a car with this setup yet.

:apl:
As usual your response raises at least as many questions as it answers...

As my planned swapped-in 013-EZL is from the same ‘92 400 as the ‘94s current ECU, will there be an adaptation period while the ECU and EZL re-acquaint themselves before I know by the seat of my pants if the swap was beneficial?

Interesting, the EZL from the ‘92 still has its clear film nicely intact on the paste, which still looks reusable as is.
Film definitely there to minimize messiness.

I think it will be a good test to swap in a 1992 400E LH+EZL into the 1994 E420, and see what happens. You'll know pretty quickly if anything is wrong, if you get weird codes stored, or an oscillating idle, or other weird behavior... that's not good. But if it remains code-free and drives ok, that's great. There should not be any significant adaptation required, just the usual bit where the '92 module adjusts to the 93-95 engine. The EZL has no adaptation capability.

Any benefits, if detectable via butt dyno, should be apparent right away. Eric's testing was showing, IIRC, a noticeable change through most of the powerband due to increased/advanced ignition timing. But I don't think he every dynod the two combos back to back (late EZL vs early EZL, in his 93 400E). Chronicles of his saga are on the forums from probably 8-10 years ago, possibly on PeachParts and/or BenzWorld, along with some postings on 500Eboard.

:pc1:
-Car is already happy with the adapted WOT ECU, the enrichment definitely works.
-EZL in the ‘94 is 015-; it was replaced years ago;
-will let you know what my butt says.
Result of EZL swap mentioned above:
Swapped a ‘92 400E EZL into a ‘94 E420 already running the LH module from the ‘92...

No incompatibility, car ran perfectly;
My butt could appreciate no performance benefit after 1 week of driving.
Maybe benefit with more octane than available 93?
‘94 EZL back in there.
 
Thanks, northNH! From memory, @400Eric's testing at the dragstrip showed several tenths of a second improvement in ET, but no change in trap speed. This indicates a bit more low-end torque, but near zero gain in top-end power. You'd need a finely-calibrated butt dyno to feel this type of change.

When the local dragstrip eventually re-opens, I may try to duplicate the results, using the same combo you have.

:burnout:
 
Thanks, northNH! From memory, @400Eric's testing at the dragstrip showed several tenths of a second improvement in ET, but no change in trap speed. This indicates a bit more low-end torque, but near zero gain in top-end power. You'd need a finely-calibrated butt dyno to feel this type of change.

When the local dragstrip eventually re-opens, I may try to duplicate the results, using the same combo you have.

:burnout:
Dave did you ever get a chance to try this combo out?
 
Dave did you ever get a chance to try this combo out?
Chris, no, I have not been able to test using the 1992 400E EZL in our 1994 E420. I need to double check that I have the correct EZL and then test this out. I'm taking the E420 to the dragstrip tonight for some baseline testing with the stock 2.24 gears, planning to swap in 2.65's and then go back to the dragstrip and see how much it picked up. I'm expecting 4-5 tenths of a second improvement, hopefully better.

In the meantime I'll try to find that 1992 EZL and see if the 1994 E420 runs normally with it.

:apl:
 
Chris, no, I have not been able to test using the 1992 400E EZL in our 1994 E420. I need to double check that I have the correct EZL and then test this out. I'm taking the E420 to the dragstrip tonight for some baseline testing with the stock 2.24 gears, planning to swap in 2.65's and then go back to the dragstrip and see how much it picked up. I'm expecting 4-5 tenths of a second improvement, hopefully better.

In the meantime I'll try to find that 1992 EZL and see if the 1994 E420 runs normally with it.

:apl:
Love it!

Put the 2.65 in and your wife will be sending me a Keg of Germany’s Finest as a thank you!!! 🍻

I promise
 

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