Poor V8 Engine Response Linked to Ignition Timing?
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From: Sacramento
AMG C43, 1999
Poor V8 Engine Response Linked to Ignition Timing?
I have have been using my Evosport PDA Scanner and I have found a trend that seems to affect the performance of the M113 engine in my C43 and other 4300cc MB engines.
While on steady state cruising on the highway or other roads at low engine loads the ignition timing is running at 28-32 degrees BTDC, but when you tip in the throttle for a little extra go the ignition timing drops off to as low as 12-14 degrees BTDC. This retarding of the ignition timing just takes the performance right out of the engine.
At full throttle 90-100 percent load the ignition timing comes back up to 25-26 degrees BTDC which is about what a very effiecient engine would make good power at.
But as I said above the retardation of the timing when pressing the throttle from 1/8 open to 1/3 open causes the timing to drop all the way down to 13 degrees BTDC and that is a killer for performance. I wonder what Mercedes is thinking!
Anyone have any thoughts on this?
Jeff
While on steady state cruising on the highway or other roads at low engine loads the ignition timing is running at 28-32 degrees BTDC, but when you tip in the throttle for a little extra go the ignition timing drops off to as low as 12-14 degrees BTDC. This retarding of the ignition timing just takes the performance right out of the engine.
At full throttle 90-100 percent load the ignition timing comes back up to 25-26 degrees BTDC which is about what a very effiecient engine would make good power at.
But as I said above the retardation of the timing when pressing the throttle from 1/8 open to 1/3 open causes the timing to drop all the way down to 13 degrees BTDC and that is a killer for performance. I wonder what Mercedes is thinking!
Anyone have any thoughts on this?
Jeff
Last edited by speedybenz; Nov 22, 2003 at 10:53 PM.
Thread Starter
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From: Sacramento
AMG C43, 1999
nov0789,
I think you missed the point.
Since my car is my hobby I enjoy finding ways to improve what MB handed out. It's not too hard either for the most part.
I don't like to wait for my car to downshift or to have to downshift it manually to get it to from point A to point B.
Glad to hear you are happy with yours.
Jeff
I think you missed the point.
Since my car is my hobby I enjoy finding ways to improve what MB handed out. It's not too hard either for the most part.
I don't like to wait for my car to downshift or to have to downshift it manually to get it to from point A to point B.
Glad to hear you are happy with yours.
Jeff
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i think what nov is trying to say is there are so many other functions going on in your car, that you probably dont understand why mb did this. i dont think that you can measure exactly what is going on with the handheld product you are using.
Newbie
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From: Dallas, TX
Bullshi... My CLK430 feels like a 4-banger if I ease into the throttle. Why should I have to slam the gas to get a little go? It's like MB thought stepping on the peddle just a little was probably an accident. Why? If I've got 275HP, why should it be available only if I mash the gas? I'm with speedybenz. The software is screwed up.
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without going into how fuel injection works, the engine will not produce maximum hp because in order to produce power, you must burn more fuel. since at light throttle you dont need the extra fuel then the computer doesnt give it so you dont have the power. i guess if you dont like the programing of the ecu, then write your own program.
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From: Sacramento
AMG C43, 1999
As mmakay says its really B.S. because when you just lightly tip in the pedal the car does nothing but sit there until you push the pedal hard enough for the tranny to shift gears, then the car rockets off.
But where is that 300 ft-lbs of torque? I honestly think MB has put some sort of limiter on the torque output in this range of engine load and throttle setting, very fustrating.
nov0798, you are way off base in your analysis. The gas is being supplied, but the ignition timing is not advanced enough to light the a/f mixture to make any power.
Ben or Vadim, have you observed this and can something be done to fix it?
Thanks,
Jeff
But where is that 300 ft-lbs of torque? I honestly think MB has put some sort of limiter on the torque output in this range of engine load and throttle setting, very fustrating.
nov0798, you are way off base in your analysis. The gas is being supplied, but the ignition timing is not advanced enough to light the a/f mixture to make any power.
Ben or Vadim, have you observed this and can something be done to fix it?
Thanks,
Jeff
Last edited by speedybenz; Nov 26, 2003 at 01:14 AM.
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From: Seattle WA
97 e420, 81 240d, 87 190-16v, Dodge Cummins Diesel
I agree with lousy throttle response from MB's. I have an E420 and 190 16v, both have throttle responses taylored towards 80 year olds.
Having played with old Dodge muscle cars, I have learned a few things:
1. Total timing at wide open throttle is usually best around 32-35 degrees for V8's irregardless of make, fuel injection etc.
2. For maximum throttle response and better fuel economy, timing advances in the order of 20+ degrees over total timing usually work best.
Has anyone installed chips and found better throttle reponse at all ranges, I see Superchips, Jetchips, Upsolute and Powerchips make them for our vehicles.
Having played with old Dodge muscle cars, I have learned a few things:
1. Total timing at wide open throttle is usually best around 32-35 degrees for V8's irregardless of make, fuel injection etc.
2. For maximum throttle response and better fuel economy, timing advances in the order of 20+ degrees over total timing usually work best.
Has anyone installed chips and found better throttle reponse at all ranges, I see Superchips, Jetchips, Upsolute and Powerchips make them for our vehicles.
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From: Dallas, TX
Originally posted by nov0798
its not that gas is not being supplied, but the amount of fuel that is supplied will not support the hp you want. no car will give you the response you want with a light throttle.
its not that gas is not being supplied, but the amount of fuel that is supplied will not support the hp you want. no car will give you the response you want with a light throttle.
I've owned 3 cars with similar horsepower to my 430. All of them automatics. All of them fuel injected. The Benz is the only one that insists that you jump into the throttle to give you decent acceleration. A simple pass on the highway shouldn't require you to give full throttle.
I'm not expecting the car to act the same way at 1/3 throttle and full. I would like to get 1/3 the power, though! As it stands, The car barely accelerates past idle. That is not a typical response for a V8 with this much power.
I agree that it must have something to do with the ECU program. So if anybody with first hand experience (not just wild *** guesses) has tried a chip or tuner-program that fixes this, I'd love to know about it.
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I will not stop posting as I do know what I am talking about. As for your lousy throttle response have you considered that maybe the potentiometer on the pedal is bad and not sending the proper signal to the ecu? Remember your the one who came here asking the questions and then you tell me that I dont know what im talking about.
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From: The President must win the Peace
to be honest, it sounds like neither one of you know what your talking about and your just throwing up wild ideas hoping someone like ben or one of the evospot guys comes here and provides a clear analysis that makes sense....
Happy Thanksgiving to all..
Happy Thanksgiving to all..
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From: WOT somewhere in the Bay Area
1951 Caterpiller D6
What kind of fuel are you running in the car? Could the timing drop be the result of part throttle detonation? If the handheld device doesn't read knock sensor output, maybe you can run a tank of 93 octane or better for a couple of hours and test again.
BTW, I put a PowerChip in my CLK430 and throttle tip in feels the same as it did before. My E55 is EXACTLY the opposite. The throttle is VERY touchy and requires a light touch to produce smooth take-offs.
Greg
BTW, I put a PowerChip in my CLK430 and throttle tip in feels the same as it did before. My E55 is EXACTLY the opposite. The throttle is VERY touchy and requires a light touch to produce smooth take-offs.
Greg
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From: Seattle WA
97 e420, 81 240d, 87 190-16v, Dodge Cummins Diesel
E55 like throttle response is what I am after. My e420 seems to intermitently act like that. Might be a problem with a sensor on my end as my fuel economy is dropping.
I went to an autocross track day and logged on 25 miles of hard track use. As the day progressed, the engine developed a missfire at low rpms and the a "asr message appeared". I have gotten a few messages to check engine electronics.
Anyways, lighten up guys. This a forum for people to vent or discsuss their mb's. No car is ever produced perfect, there is always room for improvement otherwise the aftermarket would not exist. I seem to remember a quote from a mb official concerning product quality deterioration as "there is no problem" emplying that the problem lies with the customer. Anyone who follows that beleif should bury they MB because that would be the demise of the CO. Remember, the customer is always right.
I went to an autocross track day and logged on 25 miles of hard track use. As the day progressed, the engine developed a missfire at low rpms and the a "asr message appeared". I have gotten a few messages to check engine electronics.
Anyways, lighten up guys. This a forum for people to vent or discsuss their mb's. No car is ever produced perfect, there is always room for improvement otherwise the aftermarket would not exist. I seem to remember a quote from a mb official concerning product quality deterioration as "there is no problem" emplying that the problem lies with the customer. Anyone who follows that beleif should bury they MB because that would be the demise of the CO. Remember, the customer is always right.
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From: Dallas, TX
Originally posted by nov0798
I will not stop posting as I do know what I am talking about. As for your lousy throttle response have you considered that maybe the potentiometer on the pedal is bad and not sending the proper signal to the ecu? Remember your the one who came here asking the questions and then you tell me that I dont know what im talking about.
I will not stop posting as I do know what I am talking about. As for your lousy throttle response have you considered that maybe the potentiometer on the pedal is bad and not sending the proper signal to the ecu? Remember your the one who came here asking the questions and then you tell me that I dont know what im talking about.
My dealer checked the car out, and said that everything was within MB specs. What that tells me is that MB thinks my car should be sedate unles I plant my foot through the floorboard. I'm just looking for an aftermarket tuning solution that makes the car sportier and more responsive. From E55AMG99's response, the PowerChip isn't the solution I'm looking for.
Anyway, I'm not trying to start any flame wars. I apologise for being pissy.
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From: Sacramento
AMG C43, 1999
Retarding the timing like MB is doing under light load may mean that they are also leaning out the fuel mixture too. Both of these together would cause cylinder temps to go up and exhaust temps to go really high as the lean burn A/F will have some residual burning left to do when the exhaust valve opens and will then send this extra hot gas to the convertors, maybe reducing NOX ?
But I am really starting to think this is a emissions deal as is the rest of these 3 valve motors
Jeff
But I am really starting to think this is a emissions deal as is the rest of these 3 valve motors
Jeff
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From: WOT somewhere in the Bay Area
1951 Caterpiller D6
Originally posted by mmakay
...I'm just looking for an aftermarket tuning solution that makes the car sportier and more responsive. From E55AMG99's response, the PowerChip isn't the solution I'm looking for.
...I'm just looking for an aftermarket tuning solution that makes the car sportier and more responsive. From E55AMG99's response, the PowerChip isn't the solution I'm looking for.
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From: Seattle WA
97 e420, 81 240d, 87 190-16v, Dodge Cummins Diesel
I filled up at a different gas station and noticed a huge difference in the performance of the car. No more cold start hesitations. Maybe could be the gas you are running the is causing the timing retard. Also could be partially blocked injectors that give a poor spray pattern at mid throttle. My (a 97 E420) averaged around 22 mpg with mized city/ free driving when I had them cleaned last year. I think I might take them out and have them cleaned sonically instead and blueprinted. I have heard from diesel shops that rebuind injectors that even new injectors can have variances of up to 10% in flow rates.
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From: Seattle WA
97 e420, 81 240d, 87 190-16v, Dodge Cummins Diesel
Just another note. I removed a r16 resistor on my 190e-16v and what a huge difference in throttle response. FOr those of you not familiar, it is a resistor that is added to retard the timing in North American models by 6 degrees to account for poor gas. With 92 octain, I have had not ill affects.
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W210
Speedybenz - fundamental question, have you ever used a fuel injector cleaner? The best way is to run the fuel tank down to the reserve, put a big bottle of Techron in and then add 2 gallons of gas. After that do it again. If you haven't done this, it will result in a noticeable light throttle response improvement.
I had a 400e with a K&N, exhaust, Bosch 4prong platinum plugs and a chip. Although the car was quite fast, the throttle response did not really improve until I used the techron.
I had a 400e with a K&N, exhaust, Bosch 4prong platinum plugs and a chip. Although the car was quite fast, the throttle response did not really improve until I used the techron.
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W210
E55 like throttle response is what I am after. My e420 seems to intermitently act like that. Might be a problem with a sensor on my end as my fuel economy is dropping.
When your ASR light comes on - the engine management goes into a limp mode and runs poorly until you turn off the engine. A few items to look at would be a) A coil going bad - there is one that sits over each plug, b) The engine wiring harness (Common problem in earlier V-8 W210's - however that problem is usually not intermittent), c) the MAS sensor is going out (they usually experience a slow death) and d) O2 sensors are tired and soon to go (Most noticeable when the engine warms up - it will trip a check engine light, when it cools down, it acts okay again).
Thread Starter
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From: Sacramento
AMG C43, 1999
Yes I have run quite a few bottles of Techron through the motor and it did improve response some. And I continue to add FI cleaner on a regular basis, but not at the high dose you have suggested. I will give it a try.
Jeff
Jeff
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W210
The Chevron fuel injector cleaner available at Costco or Kragen, is much cheaper and works well. When I put a bottle FI cleaner into a full tank of gas, I notice little or no improvement, until I tried using the highly concentrated mixture.
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From: WOT somewhere in the Bay Area
1951 Caterpiller D6
Does anyone know how much a new set would cost to install? Does anyone clean and recalibrate fuel injectors for cars? I know they do this for big diesel trucks and the results can be very impressive with older injectors.
