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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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Discussion Starter · #1 · (Edited)
Note: I have searched all over the forums and not found what I need.

Ok, I a working on my father's 1987 300E with 150k. He gave it to me running horribly. It was doing the whole idle poorly thing. Then I adjusted the Air Mixture a bit here and there, and now I cannot get it started again.

Once it stopped starting I replaced the fuel filter. I am going to make sure it is getting fuel tomorrow when I have my tools (left them at work). It is not the OVP as that is brand new. I have the proper tune-up parts on the ways from Mercedes Source: 201 124 126 Chassis 103 Engine Ultimate Tune-up Kit | MercedesSource.com

I know I need a multimeter to adjust the Air Mixture properly, but that requires the engine running. I need to get the engine running so i can adjust it properly. I do not know where the setting is at now. I did it slowly for a bit, then I over did it, thus the "no start". Any thoughts?

Also, where do I adjust the Idle Speed?

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Here is a summary as of 4/28/2009

Symptoms = Rough Idle, Rough start, shaking while idle, stalling, sticky/hard throttle, delay when applying throttle input. After adjusting Air/Fuel mixture in an attempt to fix this, it wouldn't start. Turned out that I had simply adjusted it to Lean (left). Got that back in acceptable range and rough idle persisted.

Resolution = Rough Idle seems to have been primarily because of a bad/worn IGNITION COIL. I am sure these other things helped along the way to get the car where it needs to be, but this was the biggie. Below is a description of my troubleshooting process. Before all of this I checked and changed all vacuum fittings in engine area.

Process =
1. Fuel Filter - Changed early on but noticed no improvement (this is my dads car though so i never drove it previously and even if i had, it was running so poorly because of other things, I doubt id have noticed improvement) Rough Idle Continued

2. Full Tune Up - http://mercedessource.com/node/498 Tuned the car up with this kit, and noticed easier start, better/smoother acceleration. Also cleaned up engine bay with the covers included in kit. Rough Idle Continued

3. Lube Throttle Linkage - Lubed with Transmission Fluid and it made a big difference. It was not disengaging all th way so when you release pedal, it would hang and cause engine to stay in higher RPMS. Rough Idle Continued

4. Replace O2/Oxygen Sensor - No difference at all so my old one must have been fine. Rough Idle Continued

5. Clean Idle Control Valve - Removed this to clean (I let it sit in diesel kleen) hit it with compressed air and let it dry. Hit it with 12v to make sure it engaged (it did) and reinstalled. Once of the hoses going into it was cracked to I replaced. This may have made it idle smoother...but it was still rough. Rough Idle Continued

6. IGNITION COIL - Did some research and decided that it might be the ignition coil...debated for a week, then ordered one. It started up rough and as usual I had to give it a little gas to get it going without wearing out the starter, but once it was running, it was nice and smooth!! I am no longer afraid to jump out in traffic for fear that it will sputter for some amount of time until it finally kicked in.

I am still having a hard start issue and I am thinking it may be the check valve so I will let you guys know when I address it. Sorry if this is confusing, it is late, let me know if you have any questions!!
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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285 Posts
Discussion Starter · #3 ·
Through the top of the air cleaner there is a hole. It requires a 3mm Allen Key. I turned it both ways while it was running to get it to smooth out and it did not work. I see you are from Florida, what part? Im in Ocala.
 

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W124
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I doubt you caused the non starting condition unless the air flow flap is now jammed in some way. First take off the air cleaner and see if the flap moves down and then returns on its own.

Next determine whether or not you have spark and fuel. If you gave it a shot of starting fluid into the air intake (the area where the flap is) it should try to start if you think it was the mixture adjustment that was wrong. Once you have verified which of the three critical components of a running engine are there, (compression, fuel, spark) let us know.

Good luck
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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285 Posts
Discussion Starter · #5 ·
Info

Ok...I disconnected the fuel line going into the Fuel Distributor and fuel come out. (Engine is off, I cannot start it). Then I disconnected one of the injector lines and cranked it and nothing came out. (The fuel pump was pumping, I heard it). Before all of this I did replace several very worn Vacuum connectors including one underneath the distributor. Also, the cold start valve does not seem to be releasing any fuel while cranking either. Next step?

Fuel Relay seems to have been taken apart before, but seems functional.
 

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'84 300D/ dakota benz trk. Sold... miss it. "88 260E '91 190E 2.6 '89 Volvo 240DL "85 300D
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just for fun... leave switch off and remove the injector line from the injector, any injector, mash down on the flap of the intake port and see if any fuel comes squirting out. if so, then it would seem that your fuel supply is not the problem.
 

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86 190E 2.3L 16V, 95 320TE 02 S500
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I think what you've done is adjust the air/fuel ratio here and there until it's so lean the car won't start. Do this little test and see what happens. Insert the 3mm allen into the adjustment tube and depress until you feel the allen engage the adjuster. Turn the allen CCW until it stops (don't be ham fisted with this, just turn easy until it stops) Now, depress the allen again and turn 3 full turns CW.

Hit the key and see if you get it to fire off. Chances are it will. Chances are it will also be running a bit rich. Go to Sears and get yourself a Craftsman model 82400 multimeter (under $40) it has a duty cycle feature that will help get the ratio in the proper range.

Report back with your result from the initial little "test"

Good Luck,

Jayare
 

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Ok...I disconnected the fuel line going into the Fuel Distributor and fuel come out. (Engine is off, I cannot start it). Then I disconnected one of the injector lines and cranked it and nothing came out. (The fuel pump was pumping, I heard it). Before all of this I did replace several very worn Vacuum connectors including one underneath the distributor. Also, the cold start valve does not seem to be releasing any fuel while cranking either. Next step?

Fuel Relay seems to have been taken apart before, but seems functional.
If the baseline adjustment on the mixture screw doesn't help I would try to disconnect the cold start injector line at the distributor and turn the key to the run position. Under normal conditions it will shoot fuel out so put a rag around this area to catch the fuel that might shoot out. When you turn the key on do so while watching for the fuel. If you don't see fuel shooting out you have a fuel pressure issue. I don't think the air flap has anything to do with fuel flow to the cold start injector but you can rule this out by depressing the flap to the bottom of its travel to see if it allows fuel to be released.
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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Discussion Starter · #10 ·
ok

Ok, I tested for spark and I am getting spark. The tested with started fluid and it got going but died once fluid ran out. I loosened the fitting that goes from distributor to cold start valve and gas spewed out, but I didn't start it while it was disconnected to see if it pump out while cranking. I am NOT getting fuel to the injectors. I tried Jayare's method with the 3mm adjustment to no avail. My Fuel Pump Relay has been pulled apart before and I actually re soldered one connection last night but that didnt change anything. Would the relay control whether the injectors get fuel or not? I "feel" like fuel is getting to distributor because I loosened the fitting going into it for a second and fuel came out pretty rapidly. Next idea?
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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285 Posts
Discussion Starter · #12 ·
Um

Sunday will not work for me...and I'd like to keep trying a bit myself. It is sort of a beater really anyhow. And I have a pile of parts on the way as well for a full tune-up, so let me take care of that and then maybe i will take you up on that offer. I am 22 and up until I traded my Nissan Pickup for my 300TD, I knew VERY little about engines. I have learned tons since then because of this forum primarily. I am trying to track down a relay right now.
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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Discussion Starter · #13 ·
OK...

Here is the current status:

I went through and replaced several vacuum fittings that were obviously not holding or about to go. One of which was under the air cleaner as indicated. After I did this, I tried what Jayare said with the three turns and it did not work. So I kept going to probably 8 turns clockwise. I also jumped it to my 300td to make sure it was getting enough power. After continuing going clockwise, and trying to crank, I GOT IT GOING!!

In hindsight, I should have checked vacuum connections before adjusting anything...I knew this but I got excited. I am still going to do a full tune up and get the Air/Gas mixture adjusted properly. It it much smoother idling, but it needs a tune up. Thanks foe everything so far, I will explain it all in a summary soon!
 

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Mercedes 1986 300E 165,000 miles
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jonbobshinigin, thanks for the update, I had the same problem so I readjusted the air/gas mixture. I went all the way max CCW but instead of 3 CW turns, the car would not start until about 10 CW turns. The car starts now but RPM drops when it get to normal operating tempt. I will replace the Water Tempt Sensor and Oxygen Sensor. BTW, I am getting 82% on pin #3 and #2 and no matter how I adjust the air/ags mixture, it does not change. Any toughts?
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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285 Posts
Discussion Starter · #16 ·
Well

I have yet to get into adjusting mine using a multimeter so I cannot help there. I am planning on doing the tune up, seeing how it runs, and then addressing the thermostat and o2 sensor. The last owners put in green coolant so if it appears that this car is worthy after tune up, ill flush the cooling system and do an oil and filter change on the transmission as well. This is my first gas Mercedes experience!!
 

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2007 E350, 2006 E350, 2003 C230K. Previous: 89 420 SEL, 87 300E, 92 190E, 91 190E
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I think what you've done is adjust the air/fuel ratio here and there until it's so lean the car won't start. Do this little test and see what happens. Insert the 3mm allen into the adjustment tube and depress until you feel the allen engage the adjuster. Turn the allen CCW until it stops (don't be ham fisted with this, just turn easy until it stops) Now, depress the allen again and turn 3 full turns CW.

Hit the key and see if you get it to fire off. Chances are it will. Chances are it will also be running a bit rich. Go to Sears and get yourself a Craftsman model 82400 multimeter (under $40) it has a duty cycle feature that will help get the ratio in the proper range.

Report back with your result from the initial little "test"

Good Luck,

Jayare
How do I use the multimeter to adjust the mixture? I believe I'm having the same problem with this air/fuel mixture thing. I turned the adjustments around and was able to get the black smoke coming out to stop. But then the car doesn't start easily when cold after the adjustments.
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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Discussion Starter · #19 ·
Info

I have not yet done that but there are several posts that explain how. I will make a detailed summary however once I figure mine out.
 

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1987 300TD - 1981 300D - 1990 190E 2.6 (Non Running for Sale) - 1993 190E 2.3
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Discussion Starter · #20 ·
Updated

I just summarized the resolution in original post, check it out!!
 
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