RBYCC

OK..let's rule out a major vacuum leak in the booster.
Back to basics..
Battery condition..voltage with engine off and with engine running.
The engine control is very sensitive to low voltage.
You replaced the OVP and MAS in 2009 how did the car run after replacement?

Saijin_Naib

So, no brake booster vac leak at all?

Battery condition is as follows:
Operating Conditions: 24F ambient temperature, engine cold, no accessories on (lights/heat/radio)
DCV (Engine Off) - 12.59V
DCV (Engine On) - 13.91V
-------------------------------
Can't get Amperage, my multimeter only reads up to 200mA which this battery obviously surpasses.

After OVP+MAS & Cap+Rotor (2007 or 2008), the car would not die out on me during regular driving (at speed, from a stop, from being turned off, etc). Basically, it was a 50/50 on whether or not the car would crap out when I took it out for a drive.

It no longer behaves that way, and those repairs + plugs/wires + fuses has left the car very reliable, except when accelerating from a stop &/or around a corner at low speed.

RBYCC

For now, let's look at other areas.

Looks good

Do you stall at any engine temp from cold to operating?

Get some spray contact cleaner..
Pull out the OVP and MAS and spray the pins and socket.
Take the distributor cap off and spray the inside of the cap, the rotor and the base insulator plate.

Have you ever put a scope on the engine while it is running and have you done any resistance tests on the high voltage ignition circuit including coil ?

Saijin_Naib

Okay, fair enough.

I'd hope so. I got that battery last February or so. It is a Walmart piece, but its also the only Group 49 battery I could find with north of 800CCA at 32F.

I'd need to pay better attention, but I believe it does happen at any temperature. I stall most commonly below operating temperature, that I can say with certainty. However, the car also runs better below operating temperature, it actually feels like it has power and responds better to throttle inputs.

Hm, okay. I'm looking to remove any gunk that may be creating resistance?
Should I replace the ignition coil? As far as my dad and I can remember, it has not been replaced during our period of ownership, so at best, the ignition coil is about 10 years old or more.
No, I've no idea what that is or how to use one.

RBYCC

Important as different components come into play dependent on engine temp.
Note if it occurs in dry or wet driving conditions

Not a resistance problem but a carbon tracking problem.
Easy to get a flash over under the cap with moisture.
When you do at low speed a minor miss will feed back and shut the engine down.

You want to clean the complete distributor inner housing, the seal and the lower insulator plate.
Look for wear, cracks or black streaks between the inner terminals.

Coil usually if failed will prevent starting or if weak a higher speed miss.
Check and clean the connections at the coil.

Make sure the grounds are making good contact.

Trying to create a logic matrix to help troubleshooting without spending money or getting too dirty !!!

Saijin_Naib

Hm, okay. I will try and take better notes on this while driving.
Fair. I will get that cleaner tomorrow and attempt this cleaning out.
I should hope its not worn or broken yet, its maybe 5 years old at this point.
I do get a lack of power around 5k rpms that sort of comes out of nowhere.
Do I just scrub them and the terminals of rust and then re-tighten? What grounding points are important? Where are the ones I need to go over?
I know I've said it before, but I can't thank all you guys enough for the assistance, guidance, and general help and info I've been given over the years. I owe you all a round of beers at the least

Shoomakan

I'm a Muslim. We don't drink.


Nooooooooooooooooooooooooooooooooooooooooooot!

RBYCC

You have some main grounding points through out the chassis.
Focus on the ones in the engine bay near relays and electronics.
Just remove the ground bolt, wire brush the wire terminals under it along with the compression area under the terminals.
Reassembly and spray with some rust/moisture inhibitor like CRC or Liquid Wrench.

Saijin_Naib

The car doesn't appear to falter when fully warmed up.
Test was done today, which was rainy earlier and still moist of air.

However, even when fully warmed up, the acceleration from a stop is a bit rough feeling until it gets over 1.5k rpms.

Here is a video of me revving it in P fully warmed up.
I feel like its revving and de-revving very slow.

300ce Warmed Up Revving:

Shoomakan

It doesn't feel especially slow, actually...

Mine is faster, but not by much. I think it's only due to the de-cat and freer exhaust.

RHW

Some of your comments sound very much like my experience with bad coils in my 95 Cab.

It showed a reluctance to rev freely some of the time, and it fluctuated when that problem showed up, sometimes when car was cold, sometimes after some miles driven.

But, when it was failing, you could not miss the fact that something was very wrong.

Saijin_Naib

Good to hear another confirmation on this matter/behavior. From what I've been reading, it looks like it could be anything from Coils to EHA to EZL or even MAS/OVP. I've got extra MAS/OVPs to test, but no luck on EHA/EZL yet (as they're simply too pricey).

However, my new ignition coil is here so I've got to replace that and then clean out the distributor cap and see what transpires.

chlippo

mmm....you can try my eha once you receive it. hows that ?

AMGDave

Some EZL's are dirt cheap on eBay, but you appear to be lucky and have one of the relatively rare / expensive ones. Bummer! I doubt the EZL is the cause of your woes though. A new EHA would make a lot of sense though, it's <$150 for a new OE/dealer EHA from parts.com. They're kind of a 100kmi tune-up item IMO, and if yours is original, it's way overdue for replacement.



Yup, might as well rule out the basics first. On the bright side, if you were to drop in a used/good motor, the money spent on ignition & fuel system parts are not wasted; they'll all work with the replacement engine too.

Saijin_Naib

Very generous I'm not sure I want to take you up on that offer, as I'm afraid of using the part before it gets to you. We'll see, its very tempting :P
------------------------------------------------------------------------------------
Ignition Coil went in, didn't come across any major stumbling blocks. It seems to start a bit easier, so that is a plus? I've not noticed anything else yet, but I'm going to go drive it now.

Edit: After driving, I can confirm it starts a bit easier now. It doesn't seem any more powerful or fast, though it does falter less at around 5k RPMs than it used to. So, looks like a slight improvement in driveability, nothing more. Guess I'll look toward that EHA next.

By the by, what does it mean when the oil that goes through my breather hose is sort of... muddy, like a coffee with some milk in it?

Here is a picture:

Saijin_Naib

You ninja-posted me :p
Should I be smelling any fuel what-so-ever from the EHA/Fuel Distributor area? It smells quite strongly there. I also hear rushing sounds when its on and running. Is that normal, or does that imply air or other obstructions in those steel lines?

Yeah, I want the most up to date EZL, since there have been about 4 revisions since mine (that still are compatible with the m104.980) and Mercedes must have had good reason for that

The EHA will happen shortly, but likely next month. My extra cash for the month has been exhausted by the Ignition Coil :\
Very true. However, I'm still more sold on the idea of keeping this engine and just building/repairing it when the time comes.

chlippo

I dont beleive that my eha will get any hurt if you try it, its plug and play. I dont mind at all as long as it will help solve your problem somehow

Saijin_Naib

Well, I really appreciate that man. Maybe I'll take you up on that offer. However, I'm not quire sure where that stupid thing has gotten to
They've not given me a tracking number or anything

Saijin_Naib

Car doesn't falter above 80C or so (when it has reached Operating Temperature and/or very close). However, below Operating Temperature (in the 40-60C range), it will falter at stop/slow speed regardless of the weather conditions.

It feels like acceleration is stronger when the car is warmed up if I'm not at W.O.T. What does that indicate? I've replaced the Throttle Position Sensor with the unit from Fred which was working in his car, so I don't think it is that.

For instance, the pull from 0-30ish in D is pretty strong if I'm at about 1/4 throttle or so. Floored, it makes a ton of noise and doesn't really do much, and still gets dead above 5k RPMs or so.

I've pulled and checked the status of the K&N. From a visual inspection, it appears to be fairly clean though it had some oil blow-by in it. No visual particle build-up to speak of, and it let light pass through when I held it up to the (cloud-covered) sun, so I think intake air is sufficient in volume.

The top flap thing over the throttle body (the weird plunger thing), actuates smoothly and does not appear to stick.

With the airbox off and the car running, pressing that plunger down any more than a slight bit would cause the car to falter and stall. I'm assuming that is the desired behavior.

chlippo

have you checked your accelerator pedal cable if its tight enough?

and for the throttle body yes this is the regular behavior if its pressed down due to too much air and not enough fuel so the car stalls

Saijin_Naib

Ah, no, I've not. I guess it makes sense that it could slacken out after 20 years, but I've not looked. Tomorrow hopefully.

Okay, good. Glad to know that is working as expected. I was reading it may be possible to tweak my EHA a bit?

AMGDave

Yes, you can tweak the EHA. I did this on my '86 300E and it improved the power considerably. It's a bit of a nuisance and you'll need new O-rings for it, and the adjustment is trial & error. There is a thread on the Fruit forum about this, not sure if MBWorld has a similar thread or not. After tweaking the EHA you may need to adjust the idle mixture as well; this is semi-advanced DIY as it requires a cable (below) along with a VOM to read the current in mA. Been years since I've messed with this stuff though....

chlippo

you can tweak the eha but i am not convinced that you will get any improvment. all what i got from tweaking the eha was problems lol. small ones, like bad idle, bad start, bad fuel cons, and the power gain wasnt a big deal. I beleive the eha tweak will get you more fuel into the injectors but with cis i think we already have plenty.

Dave that part is awesome i will buy one do you have more details on how to use it and how to get improvments?

Saijin_Naib

I adjusted the throttle cable, but there was only a turn or two I could adjust before the idle RPMs either dipped or went up to around 1k.

Guess that wasn't it either :P

So, that EHA adjustment sounds like something I shouldn't mess with for now.

AMGDave

IIRC, the EHA will richen or lean out the fuel delivery across the entire curve. If you go too far the power and fuel economy will decrease... there's an ideal setting in the middle you are trying for. On my '86 there was a noticeable increase in power after tweaking it, but it took a few tries to find the ideal setting.



It plugs in between the harness and EHA so you can connect a VOM to measure the current in mA. You check the current against the factory specs shown in the FSM (click here) in job 07.3-0121, page 89 of 173, the "actuator" is the EHA.