[tychobrahe]

Hello,

So I know there has been a lot of posts about this and I have tried to search and comb through those posts but I am not sure what to do from where I am with this car.

To start off, I recently purchased a 1989 190E 2.6L. Its been off the road for a couple of years and needs some TLC. When I went to check out the car, the guy had to jump it as it hasnt been started in a while, but after starting it, the engine roared to life and ran actually pretty smoothly. We went for a test drive and it was about 15 minutes and I got it up to 60 MPH.

I got it towed home as I driving behind the truck. When I got home, I was excited to drive it and I went I took it out for a drive, it sputtered and shut off. Luckily, I was able to limp it back home but had to restart the car many times. So I thought it was a fuel issue as I knew there was fuel in the tank.

I removed the entire gas tank, replaced the in-tank filter and inline filter and cleaned out the gas tank. It was really bad in there and I am really glad I went through that hellscape because it was damn dirty in there.

So, today, after installing the tank and new filter, connecting the lines and new gas I took it for a drive. Took a second to start it for the first time in 2 weeks but after than, she started right up every time! I did noticed though a weird sound coming from where the fuel filter/pump was (this may lead to what the issue is, but we will get to that).

So I took a drive down to the gas station and filled up, no issues. I then went to a drive through car wash because she really needed it. This where the problems came back. As the car was getting washed and just sat there, it turned off on me. I didn't think much of it, and started the car again, started up right away. However it kept happening with the car just sitting there. At one point the engine wouldnt start up, so I have to get the car in neutral and push it out of the carwash... Got it into a parking spot, started the car up and started to drive home, about 2 times the car stopped on some main streets and the final distance it stopped about 5 times before it finally got home.

Here is where I am a little lost on what I should do next. When I test drove the car it ran fine, but when I got it home it started stopping mid drive (same day). I replaced both fuel filters and cleaned the tank which it desperately needed. But the issue still occurs. I checked the OVP relay with a test procedure I found on this forum and it tested just fine (btw its an original Mercedes OVP relay, its date stamped with 7/5/89...) Could it still be the OVP relay?

I did mention went I started the car for the first time there was a weird sound coming from the fuel filter/fuel pump location, could that be my issue? A family member suggested that sludge from the fuel tank could be in the fuel lines.

I know these two things could easily be the issues I am seeing, but I want to make sure before I go buying parts that wont fix the issue. What else could I check to eliminate any other suspects?

To be honest, I know these are kind of dumb questions but I am just hoping to get some direction here.

PS. I have a new battery in and I do have new non resistor spark plugs, oil and oil filter on the way. I also replaced the air filter, but that was after I stopped driving the car.

 

[tychobrahe]

Welcome to the forum. Can I recommend putting your car details into your profile for us please? It's helpful for members - Complete your Profile

So did you get lucky and it was sludge and not rust in the tank?
Sounds like you did all the right things, the tank strainer does get blocked up.
I just wonder if it'll need doing again. Or, as you mentioned, flushing the lines would be a good idea.
Another thought is that the fuel pump might be quite tired after trying to suck through the sludge. If its the original, it would be difficult to find that level of quality again. Removing it and reversing the direction to backflush it with diesel can be a good rescue for an old pump.

Will do on the profile part.

And yes, no rust at all in the tank, just sludge. I used a pressure washer to clean the tank and a lot of stuff came out but the walls were nice and clean, no rust.
Yeah, thats something I am worried about, if itll need another flush essentially which is not a fun job.

Now that I recall, the fuel tank strainer filter (that thin filter layer) was pushed in as if the pump was trying hard to suck fuel but there was so much blockage it bent in the strainer itself. I think I may follow your advice on the fuel pump and take it out to give it a good cleaning.

I just need to find a way to stop the fuel from draining out of the hoses when I remove the pump.
Also, is there a way to check the fuel lines in a way where I dont have to take all the hoses out?

 

[tychobrahe]

Did you know about the small filter in the fuel distributor ? View attachment 2803838

I actually didnt know about that filter. The fuel distributor sits under the air filter box correct?

 

[tychobrahe]

I think the first thing I am going to do is try to run the car with the OVP relay out as I already have it out from testing it. I am hoping the engine will shut off, meaning its a fuel issue. From there I will pull the fuel pump relay and see if I can fix the solder joints. And again check from there.

 

[tychobrahe]

So I went to go pull out the Fuel Pump relay, right next to the OVP relay. I found two relays installed?

One directly left of the OVP relay and one directly in front of that. From pictures and videos I have seen, I have only ever seen one.

The one is the back looks to be OEM with the mercedes logo and "6 Zyl. 12V" and the other is aftermarket, KAE.

I am a little lost here.

 

[tychobrahe]

So I went to go pull out the Fuel Pump relay, right next to the OVP relay. I found two relays installed?

One directly left of the OVP relay and one directly in front of that. From pictures and videos I have seen, I have only ever seen one.

The one is the back looks to be OEM with the mercedes logo and "6 Zyl. 12V" and the other is aftermarket, KAE.

I am a little lost here.

So I think I may have found something. Here are pictures of the two relays. (Also my bad on the KAE one, I wiped it down with a brake cleaner soaked ragged and wiped the lettering away but it said "Fuel Pump Relay".

On the OEM relay, there was no sealant on the relay so I was able to take the cover off pretty easily. Couldnt find any broken solder points but I did find some scratches on the back and a hole in it. but no idea if thats meant to be there or not. This one has already been tampered with.

 

[tychobrahe]

Replace both with O.E. Mercedes relays

Both of have have different pin outs, is there a difference in names or part numbers I can search for and buy?

 

[tychobrahe]

Little bit of an idiot, the "kilma" relay is meant for the A/C compressor. But it was still tampered with.

The KAE fuel pump relay taken apart looks pretty bad with a dark orange stand on the circuit board. Gonna look into buying that replacement.

 

[tychobrahe]

I put in an order for a fuel pump relay. And will be waiting for that, but in the mean time, I think im going to clean up fuse contacts and double check the grounding points.

 

[tychobrahe]

tychobrahe Did you wire 7 and 8 on the relay as i posted .

I purchased a new relay. I found a good deal on one. I know it may have not been needed, but the circuitry of the old one looked bad.

 

[tychobrahe]

The relay came in today and I put it in the car.

I have good news and bad news.
Good news: I was able to take the car out for a 15 minute drive and it handled it pretty well!

Bad news: the issue is still there but less severe.

First the battery light was on the entire time, maybe a bad alternator? The battery has been sitting for a while as I working and cleaning the car.

But for the drive itself. After installing the relay, I turned the key into the accessory "on" position and I did hear the fuel pump for the 2 seconds. The car came to life right away. No issues.
I let the car warm up for about 10 minutes and it got to just below 80 degrees. I took it out for a drive and I had no issues for the first 5 minutes. After those glorious 5 minutes of no problems, the issues arose. When I got to a stop sign and started to accelerate, the engine sputtered and the gas pedal did nothing like before. But the engine never stalled or turned off, I took my foot off the pedal for a moment and then back on and it kept going (I didnt do this quickly because I thought the engine was already dead). So I kept going. When I got to a hill, the engine sputtered twice again but never turned off and it made it over the hill. Then I got to another hill (I live in between a lot of hills), the same thing happened and I got over it but this time as I was going down hill the engine turned off (it dropped to 500 rpm and then turned off).

From here, I wasnt too far from home but the shortest and safest route was over another damn hill but this one was steep. I decided to monitor my foot control of the pedal and kept the engine at 2500 rpm. It handled the steepest hill so far with no issues... That gave me hope in the sense that the car was just working out the previous kinks and it may be better.

So I decided to take the same route again instead of going home. This time it had no issues going over the first hill and sputtered on the second. But this time I noticed the rpms, every time I hit 3100 rpms the engine would sputter but not turn off. So I tested it on the 3rd and steepest hill, I gunned it up the hill and right when it hit 3100 rpm the engine sputtered and this time it did die out. However, I just turned off the car, turned it back on and kept it under 3000 rpm and it took it just fine. As I was going home, I tried flooring it a couple of times and every single time it hit 3100 rpm it would sputter but never stall or turn off. Maybe not smart to keep trying to test a failure but I wanted to confirm what I was seeing.

This makes me believe that the new fuel pump relay did help! But it did not fix everything and I am starting to think I have a tired fuel pump that just cant keep up anymore.

Let me know what you guys think. Tired fuel pump?

P.S. Two things. First, it was cold out tonight and it was around 48F and the engine stayed at 80F after warming up. Second, the reason I think its the fuel pump is because I am also hearing a weird sound from the fuel pump location and I experienced with another car I worked on but the sound doesnt sound as bad as that time.

 

[tychobrahe]

So i guess you have many issues to solve here beside the relay.
First you need to make sure that the alternator is charging( you say that you have a battery light on) just test the voltage at the battery with a voltmeter. It should be between 13.5v and 14.5v when engine is started from cold.

Second, you need to inspect the ignition system since this is may exactly cause the symptoms you are describing and you previously said that it gets worse with humidity after wash. you have to inspect distributor rotor and cap conditions and HT wires. The HT wires may be inspected by parking the car in a dark spot and let someone rev the engine till it sputters and look for any electrical sparks around the HT cables that is escaping to the ground. If you find any then you have to replace the wires.

Those are the easiest to check at first. If those are good then we need to diagnose fuel and vacuum issues.

Concerning the fuel pump i personally never seen a tired fuel pump in this model that may cause a such problem it either works either no. Even if noisy. This may needs replacement but this is not necessarly your problem.

Im sorry but what are HT wires?

Edit: I am assuming thats spark plug wires. I actually recently put in an order for a new distributor cap, rotor and wires; still waiting for the spark plugs to come in as well. Even if I didnt have this issue, I thought it would be a good idea to refresh those parts.

 

[tychobrahe]

Yes those are spark plugs wires. You did right to place an order for those and i hope you ve choosen a good brand as there s a lot of brands in the market that wont even work. The most trusted and well known ignition brands are Bosch, Beru or Bremi.
For the spark plugs make sure to get ones without resistors. Bosch H7DC, H8DC or H9DC. And not HR7DC.. the R means resistor plug which doesnt work well with the w124.
The following can be also used if you dont find bosch ones:

1]Beru 14K-9DU, 14K-9DUO, or 14K-9DPU
2]Champion S12YC, or S12YCC
3]Denso T20EPU
4]NGK BP6EFS BP5EFS

I have NGK BP6EFS coming in.
And I got Bosch replacement parts for the distributor cap and rotor. I got Karlyn-Sti spark plug wires.

 

[tychobrahe]

I have a inlet bolt with the filter coming in as well. It was $5 for a replacement.

I am waiting for all the parts to come in right now. Can't do much.

 

[tychobrahe]

Could you help me with how I can do those tests?

Checking fuel pressure and vacuum to the EZL?

 

[tychobrahe]

Thank you so much for help! Hopefully I can get to testing it soon.

I do have a question regarding timing. Lets say I do have vacuum at the EZL, is there a specific degree of advance I am looking for as the RPMs increase? Like what should it be at idle and is there a certain amount of timing advance I am looking for at certain increased RPMs?

 

[tychobrahe]

That, plus replacing corrosion prone tin fuses with copper, should take care of some electrical gremlins. I had similar issues with a distributor cap hairline crack, whenever it got a bit wet of even humid (+ check the contact spring top center.) Actually cap & rotor are the first things I change after getting an older car. Fuel filter(s), you have on your list, plus fuel pressure should be checked.
On gen II = 91 and later 190E 2.6 there is no longer a separate fuel pump relay, but a big MAS behind the battery.
When my engine died for no reason in my 91, another 2.6 specific MAS from the wrecking yard has been doing the job for the last 6 years.
In my experience, throwing new parts at an issue can become more costly than having an experienced mechanic fix the car in the first place.
If you have self service wrecking yards in your area, trying used parts doesn't cost that much.

I agree on going for used where I can. But I believe with the parts are I ordered new are more wearables like fuel filters, relays, fuses, and ignition parts.

I do actually have new fuses, completely forgot to install them when I went for a drive.. Ill do that soon as well.

 

[tychobrahe]

I dont really know if the carwash had any significance. I was able to start the car a minute after getting it out of the drive thru wash. The car had the same issues before and after the car wash as well.

 

[tychobrahe]

Hey guys, sorry I havent been able to do much on the car or post about it but I think I have potentially good news.

I have been busy with work but I decided to make some time to work on the car. The first thing I wanted to do was to check for vacuum at the EZL then check timing because I already own a timing gun. I located the EZL and unplugged an electrical plug to just look inside for corrosion and I noticed a small whitish tube disconnected from a rubber elbow coming off the middle of the EZL.. to be honest, I think I pulled it off by accident when taking out the electrical plug, but I put that back together and checked it for vacuum with the car on and it has vacuum.

I tried to find the timing marks near the pulley but I have no idea where it is and I originally was going to come on here and ask how to spot it. But in the mean time, I decided to rev the engine in the drive way and I was able to go well past 3k RPM, something I wasnt able to do before. I thought maybe since the engine wasnt under load, so I took it for a drive and there was no issues... The engine was sitting at 80 degrees the entire time and I was pushing upwards of 5k RPM, no bogging down, stalling or shutting off. It just ran.

So I think my issue was a fuel pump relay and a loose or disconnected vacuum line to the EZL.
I want to say problem solved but I am going to hold out on that for the time being.

I would still like to check timing, so if someone could help out with that I would appreciate it. I also still plan on replacing most of the ignition parts (plugs, plug wires, cap and rotor) but I am still waiting on the damn spark plugs...

Thank you guys for the help and advice, I truly appreciate it! I will keep you guys updated if anything else happens!