Man my 190E SUX!
 

I had my 1985 190E 2.3 8vlv for 8 months now and I can't find what's wrong with it. It hesitates so much and it's getting worse from month to month, I spent so much time trying to figure out what it is cause I can't afford to take it to the dealer, any money I have I put into restoring it. This is what I have done so far to get it into resonable shape.

New timing chain, new sprockets, guides, tensioner.
New water pump.
New Spark plugs and wires.
New thermostat and tehrmostat housing will be put in in the next four days since right now I'm driving without one cause the housing cracked and it leaks like no tomrorow, so in order to plug the leak me and my mech took the the thermostat so I can drive my car to work.
I also got a new fuel filter in it, did a fuel system flush and it cured the hard starts but not the hesitation.


I check all electrical devices in it to control the engine, the MAF was off so I had to recalibrate it.

I think I'm missing the Fuel Pump relay cause the pump does not shut off after a few seconds of having the ignition off, and I can't find the part, what I thought was it turned out to be the whinshield wiper relay.

Here is what happens when I drive

When cold the car performs better, but once it heats up, it's terrible, it got worse after I put in the new timing chain, timing has been adjusted to 5 degree BTDC like it is supposed to be, if not please let me know and I will try something different.

From a stand still, in indle, I step on the gase and the rpm jumps up to 1500rpm like it should but betweek 1500 and 2000 instead of going up, it starts falling, this is at about 50% throttle. If I step on it harder, the engine stutters and shakes but does not go faster, after a little bit of this it will make a POP sound and jump up and take off like a rocket, this is most noticable in first gear, in higher gears it is not that noticiable. Highway driving is perfect, car has great power, it's just these damn take offs, the car crawls, and the popping I've been told is cause of bad timing, so that's why I had it adjusted but it's even worse now.

So what do I do? I'm running out of ideas and I love the car too much to get rid of it.

I also did some tests and it seems the the EHA is not getting the right current at take off to richen the mixture for the acceleratin. When the engine pops the current goes where it is supposed to be right away, and sometimes it slowly goes up.

Any ideas anyone?

All this info is probably useless to anyone who does not know exactly how the car works.

I need help, I don't want my 8vlv to suck anymore :(

XP

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Me Too.
 

My car has almost the exact same problems...runs fine when cold, but once warmed up, it behaves the way you described. I took it into the shop, so I should have an explanation for this by monday. Oh yeah, the car is a '90 300se. At the moment, it sucks. I posted about this a few days ago, and I was advised that it could be a major vacume leak... I think the thread was called "300se hesitation."
I just spent 2 hours scraping my knuckles fixing the rear door problems and this is how the car repaid me. I think it wants to be sold...
I'll write back as soon as I have some information.

Mike

I'll be more then happy to get some feed back on this, I cleaned up all my vacuum lines and check if they are not cracked, the ones I was able to get at were fine, but maybe there is one that is JUST for this one thing that causes this to happen, I think I will start taking out all the vacuum lines and see if it gets better or worse, after all, it might just not run right?

XP

It sounds like a vacuum leak, my parent's 420SEL(I work on it) had the same problem, but there was a little U-shaped hose with a check valve on one end attached to the intake plenum that was disconnected, and the rough idle went away, but after the injector nozzle seals were changed, and oddly enough the water pump(a mechanic did all that) was replaced, the car just purrs like a kitten now.

Well so far I didn't find any disconnected vacuum lines unless they are out of sight, I will keep looking, I'm hoping this is something that's easy to fix, like a leak, cause sometimes the car will hesitate horribly and other times not at all, but most of the times it hesitates, which is why I want to fix it.

XP

Hesitation on Accel...
 

Hi Guys

I experienced the same thing last weekend driving my grandad's 1990 200E W124.

He swapped out the spark plugs and cables, popped some injector cleaner and the problem was gone. It was all done at the same time so we don't know which was the cure...

Sounds like the same problem coz halfway during acceleration (50% throttle), the car would start hesitating/jerking. In this car, there was no "pop" but the symptoms sound the same as your problem.

Hope this helps for what it's worth. Good luck!!!

:D

xp190

Don't give up.

The 190 is a wonderful car so work on getting these issues sorted out and you will appreciate it even further at the end of the day.

By the way, mine is just a "Babybenz" 190e 1.8 but I love it just the same.

Good luck!

I had these syptoms in my 190E and replacing the fuel pump fixed the problem. The pump appeared to work, but could not maintain enough pressure and delivery under acceleration.

I'm starting to think that it might be the fuel pump for me as well, or something related to the fuel pump relay. I gotta do a pressure test, I had a kit, it didn't have the piece I needed to do the test so it's inconclusive. Today I pulled out the Fuel pump relay to see what's going on, my tach started acting up and the car died, all fixed now, but the pump still won't shut off when the Ignition is on.

One question though, I don't understand how the car would only hesitate at a certain speed, if it was the fuel pump, would it not have trouble through the entire rpm range? can anyone who knows these kind of things clarify this for me? I'd love to know the theory behind how this could occur.

XP

I should also add that when I pulled the plugs and injectors about a week ago, they were all covered with dark dry dusty residue, indicating that the engine is running rich, would this mean anything to anyone?

xp

This may sound like an stupid comment but I didn't know it until someone explained it to me on this forum.

When you changed your spark plugs did you use the standard copper bosch plugs? I've heard platinum or anything but stock will wreak havoc on MB's. Just a thought.

Also what is your OVP relay like?

Take a step back ...
 

Seems to me what is needed is a logical, systematic approach to diagnosing this problem. Throwing parts at it will cost you MUCH more in the long run than finding a good independent mechanic. I'm sure Toronto must have a couple dozen of them! I agree that I wouldn't necessarily want to rush off to the dealer with a problem like this, but an independent worth his salt could spend an hour or two very productively and track it down.

If you do want to pursue this further yourself, you might want to repost it with a more appropriate and descriptive subject line. This MAY be more likely to garner some attention from the professional techs. I'd be very interested to see what Donnie or Steve B. would do to figure this one out.

T
 

Hi,
Well, I have the exact same problem as you do with my car and I think the answer has been found. There were no vacume leaks, there was good fuel pressure, fule system had been flushed, everything fine (head job 200 miles ago)...it turns out that the distributor cap has a broken part in it...it is a little black nipple in the middle of the inside that is suppossed to contact something, but isn't doinf a very good job right now...the reason for the intermittent hesitation. Might want to take a look at yours...remember I had the exact symptoms you described, so there is a good chance your problem lies in the same area.

Mike

Ps - I get the car back tomorrow afternoon, so I'll let you know for sure.