Mercedes-Benz Forum banner

1 - 16 of 16 Posts

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #1 (Edited)



First off I would like to say hello to the MB forums. This is my family's car and am not familiar with MBs but I really want to get this thing running good again because its a pleasure to drive.

So we have a 1990 300e in the family with just over 100k on it and its been having this weird issue for about two years now. It started as a cold start issue only in cold weather (30* or lower), it would just crank and crank and eventually you could get it started, it probably took 10 min or so of cranking for a few seconds and repeating. As soon as the car was up to temp it would run without any issue. However this winter it has gotten to the point were the car has no power when its up to temp.

Now the car will immediately turn over and run for a second then stall, this process has to be repeated 6-8 times before it finally will idle. Even when she is up to temp if you give it enough gas to get out in traffic it wants to die and if poked hard enough will. Hell, it even has a hard time just idling.

This video was taken maybe two months ago when the car still ran O.K. when it was up to temp.

This is a video I took two weeks ago and you can see how it has gotten a lot worse. When the RPM's are around 500 thats the car in D and when their around 900RMP's thats P. You can see when Im on the throttle because the economy gauge gets pegged and the RPM's do nothing then stumble and rise.

I have replaced the OVP with no difference, and it runs even worse with it removed. Ive read the coolant temp sensor could be the issue and checked it by crossing the pins and it seems to be within the proper range when cold. Ive also read it could be the Idle Air Control Valve and will have to check that next time Im down at the parents place. Other than that I assumed it could be the cold start valve but now that its just running badly even when warm I think thats ruled out. Also It has not spit out one CEL. New cap, rotor, plugs, wires.

Any help would be most appreciated.
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,647 Posts
racing,

Some basics will be very helpful.. When was the last time the car had new plugs, cap, rotor and spark plug wires. Last time the air filter, fuel filter were changed. Last time, if ever, that the O2 sensor was changed?

If you haven't an answer for these questions, then it's time to do all of them. Bogging down and hard to start issues can be cleared up with some basic maintenence. Anything like Techron added to a full tank of gas. This forum hs a search function and by using it, you'll discover that there is hardly any problem you have that someone else hasn't already had and solved.

Please complete your profile. It allows all of us to better help you.

Welcome and good luck,

Jayare
 

·
Registered
'04 G500, '00 E55 AMG, '90 300TE 4Matic, '82 240D
Joined
·
1,951 Posts
-___-

uhh...looks like you're missing the trim piece in front of the passenger side rear wheel well too
 

·
Registered
89 300E; 00 E320
Joined
·
2,511 Posts
What do the rotor and distributor cap look like? And did you replace the OVP with a new one?

http://www.benzworld.org/forums/w124-e-ce-d-td-class/1517243-w124-e220-1995-stall-problems.html#post4122811

WD40 sprayed around the vacuum lines and connections will rule out vacuum issues. Maybe even one is loose, look under throttle body for a couple of connections too.

Maybe fuel lines, but you would probably know if there was a leak or something there; but fuel pump and filters cause failures when bad.

Possibly even 02 sensor: Oxygen Sensor / Lambda Sensor Voltage Testing
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1557913-oxygen-sensor-lambda-sensor-voltage-testing.html

I don't know about checking temp sensor but you can do a search and probably find that out or maybe another reply will help you there.
 

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #5
Sorry about that.

New plugs, rotor, cap, and wires, air filter, and fuel filter about a year ago. It has had a recent oil change since its been sitting because of this issue. The o2 sensors are original.

Ive changed out the OVP (got it from german auto parts and has 2 fuses) with no difference. Even swapped in the old one to make sure. Ive checked the temp sensor and it seems to be working. I thought it was the cold start valve until it started running like crap all the time so that might be ruled out. Other things Ive read it could be are the IAC valve.

Im just trying to get a list of things to look at when Im back at the car that is at my parents house an hour away. I have searched for this problem and just wanted to get any extra info I could.

Yea, my sisters tagged a pole pulling into the gas station last winter. They gave it too much gas an spun the back end out:mad:


Ill try and get my profile filled out tonight as well.
 

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #6 (Edited)
I was almost sure it was a vacuum leak a year ago but have yet to find any evidence of that. I have not taken the ignition system apart assuming they were not the problem, I will take them apart when I get down there this weekend and take some pics.

Would a bad fuel "o" ring do this? I did take this black plastic fuel junction off because it is seeping some fuel.

Discovered this after the last drive and do have new "o" rings for it but didn't think it would cause the car to run this badly. It also looks recent, maybe 1,000 miles or so.




And CBC thanks for those links!! I have searched but having everything condensed like that is a Godsend. Ill make sure and check everything this weekend and get back to you guys.
 

·
Registered
89 300E; 00 E320
Joined
·
2,511 Posts
The EHA valve - can' imagine that the o rings will help so you will probably need another one.

And you may want to look at the cap and rotor again, it will only take a few minutes to make absolutely sure. I have burned through a couple of them and have even cracked one with too much torque.

How many miles did you say, because if it's the valve stem seals leaking oil, then you will probably see evidence on the plugs.

Oh and you need to clean and get some ATF on the throttle linkeage including the connectors, snap them up, clean and lube.
 

·
Premium Member
About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
Joined
·
5,454 Posts
You definitely want to take a closer look at that EHA. It is the fuel flow control device for the injection system. The o-rings don't usually leak. If the EHA is damp or shows signs of fuel leakage replace it. On one of my 88s fuel seeped out of cracks in the EHA body. The EHA is expensive at your friendly local dealer and also through parts houses. You definitely want to buy it through a MBZ parts discounter that others on this site will tell you about. If I mention mine the name will get stripped out.
After installing another EHA you'll need to tweak the duty cycle using a long 3mm allen wrench and a dwell meter.
 

·
Registered
W124
Joined
·
4,731 Posts
Agree with the suggestion to replace the EHA. They routinely cost over $250. Try Foreign Car Parts Groton (CT). They are close enough that you might have it the next day using UPS ground. They are running a 10% off thing right now and cover shipping.

It DOES sound like a fuel mixture related issue so the place to start would be to remove the leaky EHA from the equation. But do not disregard the advice to perform the duty cycle adjustement after you have replaced the EHA because it could richen up your mixture enough to get the car running well but too rich for the catalytic converters. This is a simple adjustment if you have a DVM that measures duty cycle. There is a post you can search for that goes through the process of doing the adjustment.

Best wishes on saving the car.
 

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #11
So I can't just replace the O rings in the EHA even if its not cracked? And I have not checked the duty cycle but will read up on it and check it this weekend as well. The plugs and wires ext probably have 6-10k on them and will also check them. Saturday is going to be a long day.

Thanks for all the replies guys, very helpful.
 

·
Registered
W124
Joined
·
4,731 Posts
So I can't just replace the O rings in the EHA even if its not cracked? And I have not checked the duty cycle but will read up on it and check it this weekend as well. The plugs and wires ext probably have 6-10k on them and will also check them. Saturday is going to be a long day.

Thanks for all the replies guys, very helpful.
You can try to replace the o rings but you will be the first person on this board who stopped a leaky EHA by replacing the o rings. As mentioned by Augapfel, the leak from within the plastic shroud not the o rings. Unfortunately there isn't a cheap fix for these rather defective Bosch units. And even more unfortunate is that Bosch has never changed anything on these units so a new one will most certainly leak some years down the road.
 

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #13
Well then I think that might be a big part of the problem. Hopefully I can get a replacement before the weekend. Might have to overnight parts from Germany.
 

·
Registered
1990 300e
Joined
·
7 Posts
Discussion Starter #14
Well I just replaced the EHA and it made a big difference! It took three short tries to get it running but that's a fraction of the time it use to take. Idles soooo much better, especially after putting in some fresh gas. Idle is up around 625-650 now and power is back. No more stalling or anything out of the ordinary.

For the sake of it I'm still going to check the ignition system and change the fluids while I'm here.

I'll post up a video latter.

Thanks for the help again guys! :thumbsup:
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,647 Posts
Now that the EHA is new, you'll want to check your air/fuel ratio (duty cycle). In our DIY sticky, you'll find an indepth thread on how to make the adjustment. Glad to hear the car is back on the road and I hope it delivers miles of smiles for you.

Jayare
 

·
Premium Member
About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
Joined
·
5,454 Posts
Some time last year a foreign (I think) member dissected an EHA and posted pics. It was interesting to see but I don't remember more about the post topic. If anyone knows which thread this was please post a link.
I loaned my leaky (but still mostly functional) EHA to a local shop to use for diagnosis on a non-running 89 300E. When I went back to get it they said they had thrown it into the trash! Thanks!!!
 
1 - 16 of 16 Posts
Top