400 SEL BREAKING UP AROUND 1500 RPM - Page 5 - PeachParts Mercedes-Benz Forum

400Eric · #1 02-19-2010, 03:38 AM

No, arching not arcing. I'm talking about little men under the hood with little bows shooting little arrows! Hence the term: arching.

(Just kidding. Seems I've been having a brain fart on my spelling lately.)
Regards, Eric

PETERPNYC · #2 02-19-2010, 11:14 AM

Quote:

Originally Posted by 400Eric

No, arching not arcing. I'm talking about little men under the hood with little bows shooting little arrows! Hence the term: arching.

(Just kidding. Seems I've been having a brain fart on my spelling lately.)
Regards, Eric

I will be testing for the Olympic Sport Arching or is it Archery tonight

Then I have to dig out my camera and take the photos of caps and rotors . Thanks guys for all your patience

William73 · #3 02-19-2010, 12:57 PM

Little guys under the hood doing anything would be awesome. Git your camera ready!

William73 · #4 02-20-2010, 03:08 AM

It sounds like you are onto something.

William73 · #5 02-20-2010, 04:34 PM

Did you say it ran better with the vacuum line disconnected?

PETERPNYC · #6 02-20-2010, 05:25 PM

Quote:

Originally Posted by William73

Did you say it ran better with the vacuum line disconnected?

It ran the same which was basically because I was doing highway driving and engine never gives me problem on highway or when engine remains cool.

Then today I put on new hose to EGR valve and drove around for 40 minutes in city traffic . Up hills and not a stall at all . Engine temp got to 98C and I drove up a 15% hill to really put it under load and it drove fine.

Then I stopped for a cup of coffee and after 15 minutes started her up and without waiting 30 seconds, pulled away on a flat road, and it hesitated again at 84 Celsius . Drove for another 5 minutes and did not happen again .

Stopped for a half hour and then drove for another 10 inutes No problem again.

Stopped for dinner about 80 minutes and then drove it around again for another 10 minutes (temp near 80 C) no problems. Any way the EGR could have caused all my problems ?

Anyone think the hose to the EGR all by itself , made it better and the computer has to relearn something thus the one time flat spot/ bogg down ?

If so , which I hope is true, it cost me $700 for a 50 cent piece of hose!

emerydc8 · #7 02-20-2010, 06:01 PM

This may help you to understand the EGR. It's #7 in the link below.

Quote:

1994 E320 EGR Problem

From your description, it actually sounds like your egr valve is stuck in the open position. There is no "internal engine valve dealing with the EGR system". The only component of the egr system is the egr itself.

Here is how the system works.

There is a way to check if your EGR valve is not working due to a plugged up hot inlet pipe, or if the valve itself is sticking (sticking in the open position or sticking in the closed position.):

The ECU sends an electric signal to the switch-over valve which opens the EGR valve to engine vacum. The vacum pulls open the diaphragm on the EGR, allowing some of the exhaust gas to recirculate back to the intake manifold (thus the name, Exhaust Gas Recirculation). The purpose is to reducing emissions.

The ECU will not send this electric signal at idle or wide open throttle, or until the engine has warmed up. So, if you hand pull about 12" of vacum on the EGR at idle with a warm engine, you are creating a very lean condition (vacum leak) and the engine will attemp to stall and run very rough. This tells you not only that the EGR is opening, but also that the hot inlet pipe is not completely plugged up. If, when you pull vacum and nothing changes, then you know that either the valve is not opening up, or the hot inlet pipe is completely blocked.

Now, release the hand vacum and the EGR should snap shut. Engine should smooth out.

In your case, your car is idling rough when cold, and the problem cleared up when the engine warmed up. This describes an egr that is stuck open.

There is another possibility that the diaphragm in the EGR itself may leak and cause an internal leak. The test for this is to see if the hand vacum will hold the EGR open for a period. It is common on vacum leaks to not be as noticeable with a cold engine as the engine is running rich and that helps off-set the added intake of air caused by the leak.

Last, when you clear the check engine light, it takes the same fault to occur over a specific period of time for the check engine light to come on again. It may take a few days, or even a week, but it will come on again.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

PETERPNYC · #8 02-20-2010, 08:33 PM

Quote:

Originally Posted by emerydc8

This may help you to understand the EGR. It's #7 in the link below.

Emery please read my above post #53 which I have edited. My problems were not inspection emissions related but much more serious hesitation/ stalling problems that at least for the moment have improved tremendously, or gone away completely . ( I say this after only 5 quick trips , with one appearance of the problem)

Simple question is can a broken hose ( loss of vacuum ) to the EGR cause those types of problems. Can anyone answer that question and no more info needed.

400Eric · #9 02-22-2010, 06:22 AM

Spark plug wire arcing will not be visible unless it is totally pitch black unless the wires are really bad.

Your M119 W140 is definitely a LH-SFI not the CIS-E. Same would be true even if it was a 92.

While you are on Jim F's site, you should read about and then do his "cool harness" mod. He tells you how to do it yourself (It's very easy) or you can buy his plug in kit. I swear by the mod and many guys who are way more knowledgeable than me swear by it too.

California cars got the self diagnostics system and the "Check Eng" light that goes with it before the rest of the country did so it's possible that your car didn't come with it especially if your car is an early 93. All 92 and later 500Es supposedly got this system regardless of whether or not they were Cali cars but my buddies 92 500E doesn't have it. It is an early 92 BTW. The point is if your car doesn't have it, it doesn't mean something is wrong.

Another crazy thing that has popped in my head is the possibility that the cats are beginning to plug up. I don't think this is "it" but it's something to keep in the back of your head if all else fails.
Regards, Eric

el sea · #10 02-22-2010, 09:05 PM

This sound like degraded fuel, we see this a lot. Runs ok at lower rpms, then when asking for more, they stumble...

400Eric · #11 02-26-2010, 03:38 AM

Yes, change the oil after the Techron treatment. I don't know about the Lucas, but the same probably applies. It's because some of that strong detergent ends up in the oil, compromising it.

What ever happened to the spark plug wires?
Regards, Eric

PETERPNYC · #12 02-26-2010, 10:56 AM

Quote:

Originally Posted by 400Eric

Yes, change the oil after the Techron treatment. I don't know about the Lucas, but the same probably applies. It's because some of that strong detergent ends up in the oil, compromising it.

What ever happened to the spark plug wires?
Regards, Eric

MY new mechanic test drove it when it was warm and breaking up under load , and changed his theory about plug wires. Now he says they are not the problem .

He made me use a Lucas additive and is searching for used injectors to swap out

400Eric · #13 02-27-2010, 03:48 AM

Do not let anyone do another thing to that car until they know for sure what exactly is wrong with it. A good mechanic should be able to figure it out without throwing parts at it. Anyone can do that!

Finish running that cleaner through your engine. Change the oil once it's done. Build and then use the code reader!

As cold as it is right now where you live, that "white smoke" just might be steam.
Regards, Eric

emerydc8 · #14 02-27-2010, 04:20 AM

I agree. The code reader should not have been a skipped step.

PETERPNYC · #15 02-27-2010, 01:09 PM

Quote:

Originally Posted by 400Eric

Do not let anyone do another thing to that car until they know for sure what exactly is wrong with it. A good mechanic should be able to figure it out without throwing parts at it. Anyone can do that!

Finish running that cleaner through your engine. Change the oil once it's done. Build and then use the code reader!

As cold as it is right now where you live, that "white smoke" just might be steam.
Regards, Eric

Eric do you think the code reader I would build is better than the 39 pin scanner that 2 Mb mechanics have used? I have physically watched him use it and draw no codes . What will I gain by using the one I build.