The M119's mileage is really good for a 1990's V8 I think. The 4.2 gets 17mpg (all city driving) and combined i get above 20 and highest being 25 (almost all highway driving)..

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2008 BMW 335i Coupe

Cooler air is denser that warmer air - Denser air allows more fuel for a given volume of air and viola, more power.

M119 V8 400E has noticably more power at 40F than at 90F. There may be something in the ECU but it really seems to dial the power back when the temps rise.

Tim

gsxr, i have same problem, i think same thing, cam timings. I also feel that there is more torque at higher rpms. m119 should have quite flat torque band according specs. But again, it is hard to me to measure without comparison to another 500E.
I have made full throttle accelerations only when engine has fully warmed up.
Does anyone know how ECU controls cam timings? There is cam sensors for both heads and also magnetic actuators to release oil pressure to timing change mechanism. Does ECU measure timing difference got from crank sensor to cam sensors? If this is under closed loop control, then there should be error log if timing is not right??

My cousin has a 92 500E and I asked her about this. She has not noticed any power difference at temp except for the draw of the AC compressor. And before jumping to conclusions (she being a she) she does drive the car very hard on occasion.

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

There has been a bunch more info posted at the other thread (on 500E.com, linked in an earlier post) that's interesting. Gerry in Portland says his 500, in mostly stock form, can roast any street tires with ease (cold OR hot) and he has video of it at the strip doing so (video links posted in the other thread). But Glen's 500 acts like mine, it will spin his 275/35/18's when cold, but barely if at all when warm. Hmmm.... very odd. The question of tire traction improving when the tires are warm was brought up, but Gerry's data kind of poo-poo'd that theory. (?)

Thanks to all for the ideas/suggestions, please keep 'em coming...!

Couple of other things...

1) Are the 94's subject to the wiring harness problem? Have you taken a look at your main wiring harness?

2) I thought the cam solenoids were to advance the timing at high RPM ranges - as I recall the default is retarded timing so a faulty cam actuator would not cause low power from a launch condition.

3) Any chance the ASR defeat switch is somehow fooling the EA circut to not give you full throttle under certain conditions?

I'm not really fond of the drive by wire idea but I'm afraid its pretty much here to stay.

Have you done any code reading from the EA/CC/ISC manager?

Hi Tim,

1) Yup, the 94's do have the harness issue. Mine *looks* fine, no peeling or cracked insulation, and it's not hardened significantly either. The price shot up ~50% to nearly $500 (wholesale!) so I'm really trying to avoid replacing that just to see if it fixes the problem...!

2) The cams are retarded at idle & starting, then advanced at low/mid RPM, then retard again at high RPM. At least I'm 99% sure that's how it works. If there's still doubt, I'll look it up in the manual and post the exact RPM ranges, etc...

3) I don't think so. The ASR was installed at BergWerks and I think those guys know what they're doing. (ok, at least I hope so. )

4) Drive by wire....? I didn't realize the M119 had that kind of stuff... you mean the throttle cable just opens the butterfly for airflow but does nothing for fuel, which is controlled 'by wire' via the LH? Hmmmm.... interesting.

5) I haven't pulled any codes. The TBA was replaced before I got the car, it's new, the old one was thowing codes and causing a stall during U-turns which was cured with the new TBA. Can I pull codes myself without a reader, or do I need to buy a reader...? I've never done this, my 603 diesels are mechanical, no need to play with codes on those!

Dave

It's even worse than that - in this car the accelerator pedal is NOT directly connected to the throttle butterfly plate. Your inputs at the gas pedal are interpreted by a computer that then directs an electric motor to actually move the throttle plate. This kind of setup greatly simplifies cruise control/idle speed correction and ASR operations but also makes diagnosis of problems very difficult unless you have access to the proper code readers and have knowledge of how to use them.

I'm wondering if there is some sort of electronic gremlin that is not permitting the throttle plate to fully open under certain operating conditions.....Maybe the professional techs could provide some insight

The TBA (also called the EA accuator - for Electronic Accelerator) is a common failure item in these engines, mine was replaced at least once.

I've never read the codes in my 400E - I do remember doing some research on what would be needed and thinking I would not bother until I actually had a problem. I'll take a look at my documentation when I get home and see what is involved with code reading.

Tim

Interesting, if opening of the butterfly is behind dc motor and computer, things are quite nasty to solve. If opening speed of the butterfly is controlled, then wheel spinnig can be easily avoided, just open butterly slighly slower to wide open, so wheels don't spin. Still you have the all the power available for top speed. Can this be a software feature with some 500E ?
Or if there is a wear or dirt at EA, it can open slowly or not fully open, but still working good enough that ECU doesn't show error codes?
When ASR cuts power when detecting spinning, does it affect only to the butterfly(just reduce opening) or does it something else also(cut fuel delivery)?
I have also w124 turbo diesel,which seems to be only choise to drive if you want to do you own maintenance.No electronics, no worries.

Tim Freeh's description of the EA or TBA is pretty much as I understand it as well. I think, however, that a lot of the TBA's have been needlessly replaced. You really should find someone, with experience and a Mercedes Star Diagnosis system, to check your car for stored and current faults before considering replacement of the expensive items.

I suggest studying JimF's website. His description of his aux cooling fan piggy-tails points to a potential source of your problem. The engine performance is related to operating temperature. Jim offers different resistors to kick on the aux fans at different lower temperatures. Using JimF's little gizmo will keep your engine's operating temperature in a much narrower and lower range. I think that's really beneficial for engine life. One caveat: I installed one of his piggytails in my wife's 300TE. It does a good job keeping her car running cooler and at a more consistent temperature, which helps to keep the M104's chronic head gasket oil leak in check. However, in our hilly neighborhood, the aux fan runs a lot and I've had to replace a melted fan solenoid one time in the past two years since installing the piggy-tail. No such problems with my 500E.

BTW, my 500E has a chip, K & E filters, and the piggy-tail. It's otherwise stock. Normal operating temperature is in the mid-90's C. In first gear starts it spins the tires (245/45-17 S-03's) hot or cold.

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Mark Stetson
1995 E320 Wagon Moonstone Grey/Parchment 106K mi.
2007 E63 AMG Graphite/designo 75K mi

Thanks, Mark. My car has JimF's resistor mod, or so I'm told, at the lowest of the 3 temps listed on his website. I have not looked at the resistor to verify this. My engine temps are in the 85-95C range most of the time, so engine temp doesn't appear to be an issue (I have heard of others with M119's in the 105-115C range in summer. )

My car had the TBA replaced by the PO to cure a stalling issue, and it was throwing codes as well. So that's new, and definitely clean & shiny - the old part (which I have in a box) was FILTHY on the bottom/hidden side of the butterfly! I'm kind of curious what a RENNtech chip would do, I have one that's awaiting installation, but I kind of wanted to "fix" the car first before putting the chip in.

I may have to find a chassis dyno to get some hard data to compare with other people's M119.974 dyno runs. I hope to do some stopwatch and AP-22 performance computer testing tomorrow or Saturday, which I'll post here...

OK, here's more info. First, I verified the speedometer accuracy with the newly-mounted 18-inch wheels, Indicated - Acutal:

25 - 25
50 - 50
75 - 75
100 - 99
120 - 117 (!?)

Anyway it seems very very close to 100mph. With that done, I did two stopwatch runs to 100mph. Both were about 16.5 seconds, no wheelspin at launch. I did a few more 1/4 mile runs with the AP-22 as well. Here's the BEST numbers from last week, and today (engine temps 85-90C for all runs) :

Last week (60F, 92 octane, stock tires)
15.11 @ 95.2mph, 60' time 2.66, 0-60 = 6.62

Today (67F, 95 octane, 275/35 S-03's)
15.42 @ 92.4mph, 60' time 2.72, 0-60 = 6.91

Full data on all 9 runs (six last week, three today) are in this text file for your enjoyment:

Attached Files

e500_times.txt (3.2 KB, 149 views)

If you're not loading the converter at standing, then those are realistic times. Our 1995 C36 lost about 1.5 sec in the Q when leaving from idle. Loading the tranny to the stall speed made a HUGE difference.

A good time for an E500 is 13.9-14.1.

Your trap speeds are slow though. It should be 95+, and getting close to 100mph.

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

I've been lightly loading the t/c at launch, say 1200rpm or so, I wasn't watching real close. I believe I did some runs with it well loaded and there was no difference but I'm not sure now. Guess I'll do a couple more, and report if there's any significant change. I agree the trap speed should be closer to 100, but IMO the data shows the biggest loss is in the first 60'... good times would be 2.0-2.2sec, not 2.7! Hmmm...

I tried aggressive power braking, and there was NO change. The car will start to spin the rear tires with the fronts locked, so there's obviously a point of diminishing returns. I usually load the engine to something like 1000-1200rpm against the brake and then nail it, that seems to work pretty well.

My launch seems to be the problem, due to the decent trap speed - which is why I'm guessing the issue is with low RPM power, not top end (also top speed isn't a problem, if the engine was weak on peak power, top speed would be a problem!) I can schedule a dyno run at the local speed shop for $75, maybe I can squeeze that in next Friday?