can you flud a diesel by pumping the peddle to much - Page 2 - PeachParts Mercedes-Benz Forum

Knightrider966 · #16 01-24-2007, 02:41 PM

Quote:

Originally Posted by tangofox007

internet etiket is amazin u kan mis-spell every thurd wurd don't not never uze gud grammur & kompletely fale to uze punctuation and it's totalllly acceptable (or, as some would say, exceptable) but watever u do dont use no KAPS!!!!
folks wil think u got no cents

Yep, that's right, we be dumb!!! Just don't shout it out!!!! ROFLMAO

rrgrassi · #17 01-24-2007, 02:51 PM

Quote:

Originally Posted by spark3542

I'm confused on this one. I absolutely see a difference in starting when I have some pedal depressed. I purchased my 83 300SD in the summer and it started fine no pedal, idled about 400 rpm indicated (which seems mightly low to me from my gasser experience). As the weather began to cool off in the fall, it would start, run about 2 seconds and die. Start again and run fine. When it began to stall twice, I decided to add a little pedal (about 1/4) while starting and it made a huge difference. I would only have to start it once. If it was a really cold engine, it would start, cough and sputter for about 5 seconds, then come around.

My experience certainly indicates that mine is not getting full fuel at start with no pedal depressed. Is there something wrong with my system?

Mark

How are your Glow Plugs? Mine was the same way until I replced the GP's. It was actually a forced replacing because the 80 amp fuse blew. One GP read 0.2 ohms resistance. The rest were 0.6 to 0.8.

Also your rack damper pin may be adjusted too tight. This will also result in poor cold idle. Also check you fuel filters.

BodhiBenz1987 · #18 01-24-2007, 03:05 PM

Quote:

Originally Posted by spark3542

I'm confused on this one. I absolutely see a difference in starting when I have some pedal depressed. I purchased my 83 300SD in the summer and it started fine no pedal, idled about 400 rpm indicated (which seems mightly low to me from my gasser experience). As the weather began to cool off in the fall, it would start, run about 2 seconds and die. Start again and run fine. When it began to stall twice, I decided to add a little pedal (about 1/4) while starting and it made a huge difference. I would only have to start it once. If it was a really cold engine, it would start, cough and sputter for about 5 seconds, then come around.

My experience certainly indicates that mine is not getting full fuel at start with no pedal depressed. Is there something wrong with my system?

Mark

Bad injector, maybe?

Yeah, 400 rpm does seem awfully low. I can't really tell you how to adjust that, as I know my 603 is different in that regard (on mine there is a knob on the drivers side firewall).

OMEGAMAN · #19 01-24-2007, 05:39 PM

Quote:

Originally Posted by Shorebilly

I don't think it's possible to flood a diesel engine, if the engine is in good running order.

When one "Floods" a gasoline engine.....a carbureted gasoline engine....when one pumps the accelerator/gas pedal, there is a pumping device within the carb (accelerator pump) that squirts a bit of fuel into the manifold every time that the pedal is pumped.....flooding is the condition of having a fuel /air mixture that is too rich for combustion.....

I don't think that flooding of a "Fuel Injected" gasser is possible either....given that the computer and associated sensors are in good order.....because no fuel is injected until the computer allows it.....pumping of the gas pedal has no effect here either.....some of you ASE folks should maybe describe this a bit better than I.....but if one reads the owners manual of a gasoline FI car or truck, it should tell you NOT to touch the accelerator until the engine catches and runs......

A mechanical FI Pump....like the ones on the OM617 and earlier engines....no fuel is injected until the engine actually cranks....because there is no motion within the FI Pump (Plunger/Barrel) until the engine is rotated thus rotating the FI Pump.....yes the fuel rack will be at maximum fuel for starting, but pumping the accelerator pedal does nothing in way of adding fuel to the cylinder.....

Now if you have a low compression or extremely cold diesel engine.....and you crank the engine excessively, you can wash the lubrication off of the cylinder walls and get fuel into the lube oil as the fuel builds up in the combustion chamber.....the compression forces the unburned fuel past the compression rings....

FYI you can flood a modern injected gasoline engine by depessing the gas pedal part way down. If you leave the pedal at idle the computer controlls everything. If you push it to the floor you get clear flood mode where little to no fuel is injected. If you push it part way you increase the amount of fuel injected and run the risk of flooding.

aceofspd · #20 01-24-2007, 09:37 PM

Quote:

BTW, turning off the caps lock will get you more responses. Most people will not even bother to read a post in all caps.

I always thought that was the dumbest thing I ever heard. Many areas of business use all caps as standard. Pharmacy labels, signs, architectural drawings, etc.
I did not even notice, did you?

justinperkins · #21 01-24-2007, 10:21 PM

Quote:

Originally Posted by aceofspd

I always thought that was the dumbest thing I ever heard. Many areas of business use all caps as standard. Pharmacy labels, signs, architectural drawings, etc.
I did not even notice, did you?

Communicating on the computer is not quite the same thing as any of the other things you just mentioned. Signs are in all caps probably because otherwise they'd cost twice as much to make (two sets of stencil lettering instead of one). There's probably a reason for the pharmacy and architects using all CAPS, but that doesn't mean everybody should use all CAPS all the time. It's hard to read and in internet speak it means you're YELLING!

tangofox007 · #22 01-24-2007, 10:37 PM

Quote:

Originally Posted by aceofspd

I always thought that was the dumbest thing I ever heard. Many areas of business use all caps as standard. Pharmacy labels, signs, architectural drawings, etc.
I did not even notice, did you?

No. FWIWICNCL. (TIISYMNU)

#23 01-25-2007, 12:13 AM

Quote:

Originally Posted by aceofspd

I did not even notice, did you?

Yes, I did notice. I would have not read it if I was not bored at the time.

ray m · #24 01-25-2007, 01:38 AM

Quote:

Originally Posted by ForcedInduction

Yes, I did notice. I would have not read it if I was not bored at the time.

I do have a bad habit of using all caps. As I looked over what I wrote I see what you mean. I have a problem with with remembering to use a capital at the beginning of my sentences and I have to keep going back to correct that. Thus i thought to use all caps to make it easy for me. I truely appreciate the time you took to read it because you helped me out once again as you have many times in the past. I don't understand all the hoop-la about it that we drew from it but thanks for your suggestion. I do appreciate that also. From what I've seen your intentions are always good and concerning. Thanks ForcedInduction. RAY M

maddogg20 · #25 01-25-2007, 02:00 AM

To my knowledge of Fi engines, it is not possible to flood it, unless you have a leaky injector, or very high fuel pressure in which case your engine might not start at all. When you engine is cranking, the ECU tells the injectors to shoot a predetermined amount of fuel into the cylinders, no matter what position your foot is in, unless it is in clear flood mode like another member said. The reason for this, is when you press the accelerator pedal in a FI car, you open the throttle body which provides more air, not fuel. All you are doing is leaning out the mixture, but it still will start. The computer doesnt read the mass air flow sensor, or even the map sensor during initial startup. Yes, sometimes pressing on the accelerator pedal during startup in a Fi car may make it more difficult to start, depending on the vehicle, and what program its computer has, but every car will have a set amount of fuel that it has the injectors squirt out during initial startup, no matter where your foot is.

not to be a dick, or anything. I just know this because at the Ford dealer I used to work at we had this customer who kept coming in saying that his car was flooding. (99 explorer) and we had to explain to him how it wasnt possible. turned out to be a bad crank position sensor.

vstech · #26 01-25-2007, 09:08 AM

I would think a FI gasser could flood, if the plugs were bad... fuel getting pumped in, but bad compression... of course, if the plugs were bad, the flooding would be the least of his problems.
John

Meridivs · #27 01-25-2007, 09:27 AM

I also noticed that my OM 617.912 engine starts a lot easier when I put the pedal half way down when turning the key.

If I don't touch the pedal at all it could take as much as 5 seconds for it to start with a cold engine (left overnight). When engine is warm the behaviour is pretty much the same - it starts easily but much easier with the pedal down (1 turn vs 2 or more turns to start).

Notice the I had my injection pump and all injectors replaced 8000 miles ago. The engine has been rebuild back then with new parts and has no blowby or oil consumption so far.

jnc19610 · #28 01-25-2007, 11:44 AM

Just a flooded gasser comment. (I think I saw a wrong one)

Generally speaking.... on a Fuel injected gassers (63 vett's excluded)
If you floor it, it turns off the fuel, allowing a flooded engine to start.

Modery FI gassers start without touching the pedals. If it coughs or sputters, like its flooded. Just floor it as you crank.

Don't forget to let go of the gas pedal after it starts

Brian Carlton · #29 01-25-2007, 05:26 PM

Quote:

Originally Posted by spark3542

I'm confused on this one. I absolutely see a difference in starting when I have some pedal depressed. I purchased my 83 300SD in the summer and it started fine no pedal, idled about 400 rpm indicated (which seems mightly low to me from my gasser experience). As the weather began to cool off in the fall, it would start, run about 2 seconds and die. Start again and run fine. When it began to stall twice, I decided to add a little pedal (about 1/4) while starting and it made a huge difference. I would only have to start it once. If it was a really cold engine, it would start, cough and sputter for about 5 seconds, then come around.

My experience certainly indicates that mine is not getting full fuel at start with no pedal depressed. Is there something wrong with my system?

Mark

It's an interesting concept and discussion.

From what I understand about the IP, the following scenario applies:

When the engine not rotating, the IP will advance the rack to the full fuel position. This will be maintained during cranking.

Somewhere between crank speed and idle speed, the flyweights within the governor will move outward and rapidly move the rack back toward the idle position. When the engine reaches "idle" speed, the rack is fully retracted to the idle position. The driver had no idea that the rack was ever in the maximum fuel position.

But, some engines won't idle on the idle stop when dead cold. They need more fuel. This engine will light off and immediately stall because there is insufficient fuel on the idle stop with no pedal. I'd bet that most 617's will suffer this malady if the ambient temperature is 0F. or below.

So, by pressing the pedal down 1/4, you don't allow the rack to return to the idle position when the engine "starts". Therefore, you notice that it "starts better" because it has sufficient fuel to remain running.

Now, if I could just understand the owner's manual that recommends to press the pedal to the floor three times when the temperature is below 0F. If the rack is fully open.............what's that accomplishing?

Shorebilly · #30 01-25-2007, 05:55 PM

Quote:

Originally Posted by Brian Carlton

It's an interesting concept and discussion.

From what I understand about the IP, the following scenario applies:

When the engine not rotating, the IP will advance the rack to the full fuel position. This will be maintained during cranking.

Somewhere between crank speed and idle speed, the flyweights within the governor will move outward and rapidly move the rack back toward the idle position. When the engine reaches "idle" speed, the rack is fully retracted to the idle position. The driver had no idea that the rack was ever in the maximum fuel position.

But, some engines won't idle on the idle stop when dead cold. They need more fuel. This engine will light off and immediately stall because there is insufficient fuel on the idle stop with no pedal. I'd bet that most 617's will suffer this malady if the ambient temperature is 0F. or below.

So, by pressing the pedal down 1/4, you don't allow the rack to return to the idle position when the engine "starts". Therefore, you notice that it "starts better" because it has sufficient fuel to remain running.

Now, if I could just understand the owner's manual that recommends to press the pedal to the floor three times when the temperature is below 0F. If the rack is fully open.............what's that accomplishing?

You have described the events occurring within the FI Pump about as simply and clearly as I have ever heard.....

Perhaps the MB owners manual is a misprint left over from a gasser owners manual.....maybe just an oversight......in out lousy English......mashin' on the gas pedal don't do squat.......

SB