Mercedes-Benz Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1
When I step on the gas pedal to fast my "90 300 CE has a long delay before it takes off. If I fether the pedal lightly, it speeds up slowly and then will maintain the spped fine. I've recently done a tuneup including new fuel filter. My parts guy thought it might be sensor on the back of the fuel injection "distribution box", but when he looked at it today, he said it wasn't leaking (as he had seen before) and didn't want me to just buy one because they are expensive. Any ideas?
 

·
Registered
300TE 4-Matic 300GD
Joined
·
330 Posts
Hi Billymb.

When you take the car in for the next step in diagnosis, ask them to check if the cams are worn.

In my experience, if an EHA valve leaks so much that heavy acceleration is affected, it will not run at idle. Smell of gas after driving, fluctuating idle, and hard to start warm are early signs.

From the data you give, it's the best idea I could think of.

Good luck.

Regards

Geir
 

·
Registered
300TE 4-Matic 300GD
Joined
·
330 Posts
Hi again.

"If it were the cams, wouldn't it be bad all the time?"

Well, yes in theory. But it depends on what you mean by sometimes. If you can for example stop the engine, start over, and the fault is gone, I agree. But if it's good when cold, OK when driven nicely and easy, and then given the occasional short burst, but starts failing when engine is warmer than usual, it's an indication. Very great strains are put on the cams surfaces.

In the very beginning, it will occur infrequently. Then it will gain in frequency and intensity. In the end it will be clearly apparent, and unmistakeable.

Checking them is easy and quick. Combine it with a compression test. And check the timing chain and valve lifters. Never hurts to do this anyway. I always do that very early in diagnosis with your symtoms. Because if you do that after you have exhausted every other possibility, and that's the cause, you'll be sorry.

Anyway, if you recently had a tuneup, one should think the components are fine. Besides, having a transcript of a compression test, is a little like having cardial sheets showing the normal rythm and beat. So that one can compare later, if in doubt.

This is also one of the areas which are highly affected by not changing oil often enough, and using wrong spec. oil. That's a chance you have to take when buying a used vehicle.

Regards

Geir
 

·
Registered
Depends on the day!
Joined
·
13,337 Posts
Have your fuel pressure tested. How old are your pumps? Once the car is rolling does it make good power all the way to redline??

More details please:)

Jonathan
 

·
Registered
Joined
·
5 Posts
Billy:

I have a '90 300CE and your problem sounds ominously like the problem I recently had. Every now and then, mostly when cold, I had to "feather" the accelerator or the engine would bogg down. I thought it was a fuel starvation issue. Before this problem could become persistent, I had a big-time failure - the engine quit and would not start. I hate to tell you this, but my problem turned out to be a faulty ignition control module. You may be aware of the fact that the M104 in the 300CE has a unique module which is very expensive and rare - dealer price $2600+ new! However they can be rebuilt for $975 (with one year warranty). I got lucky and found a used one after a nationwide search for much less.

I hope your problem is simpler and less expensive but I thought you should know. It is possible that in my case the two problems were not related and I will be reivsited with the bogging problem. So far so good (3000 miles).

Cary
 

·
Registered
Depends on the day!
Joined
·
13,337 Posts
I'll have to show ya'll what I did to take the air idle valve out of the equation in my wagon.. But that aside, who is rebuilding ignition control modules??

Jonathan
 

·
Registered
Joined
·
31 Posts
Discussion Starter #11
No, The wires are original. My wife took the car for the weekend and drove it across Washington State. Next week I plan on checking out the wires by watching them in the dark and looking for "fireworks". The gap on the plugs is right, because I checked them as they went in. When I moved the wires out of the way most of the clips just fell apart. I tried to make due with some aftermarket wireclips, but its not the same.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #12
Can you give me a hint where I might find this. Is this the part that I read about that needs to be soaked overnight?
 

·
Registered
Joined
·
5 Posts
jhodg5ck - 4/10/2005 12:22 PM

I'll have to show ya'll what I did to take the air idle valve out of the equation in my wagon.. But that aside, who is rebuilding ignition control modules??

Jonathan
Jonathan:

AutoTruck Electronics is rebuilding ignition modules (and much more). autoecu.com

Cary.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #15
UPDATE!
I had a guy take it to a dealer and get the codes read. It came back that the voltage at the air flow sensor was too high, too low...Recended fix is replace it at $850+labor
and
Fault in CAN communication with EFD control module...Don't have the cost on this part yet

Is this the same control module that lists for 2600? I plan to check with autoecu.com to see about the rebuild next
 
1 - 15 of 15 Posts
Top