my dad does the car work, I just watch and try to be helpful.
Needs the help
Thread Starter
MBWorld Fanatic!
Joined: Jun 2006
Posts: 4,968
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1990 300ce 24v I6
Needs the help
Okay, my 300ce is giving me issues. From what I have read so far here it sounds like it could be one of these many things:
1)OVP (thanks shadow)
2)Fuel Pump
3)Fuel Pump Relay
4)Mass Airflow Sensor
5)O2 Sensor
Symptoms:
Sometimes car wont turn over, no matter what. Usually resolved by waiting (or charging/jumping the battery, though its only a year old).
Once the car cares to turn over, it will do one of two things:
1)drive away like nothings wrong
2)studder and stall and ****/moan
If it does 1, it will start to do 2 shortly after, usually a minute or two into driving. This studder/stall behavior is usually accompanied by the fuel gague going wonky. This is typically demonstrated by the gague flicking from current fuel level to reserve, back up, somewhere inbetween etc while the car is on the fritz.
My dad and I are going to take some time to poke around the CE this weekend, and I dont want to be throwing parts (or other things if I get pissed) at it, so if anyone has any suggestions of where to look first, I would be eternally grateful.
Thanks homos
1)OVP (thanks shadow)
2)Fuel Pump
3)Fuel Pump Relay
4)Mass Airflow Sensor
5)O2 Sensor
Symptoms:
Sometimes car wont turn over, no matter what. Usually resolved by waiting (or charging/jumping the battery, though its only a year old).
Once the car cares to turn over, it will do one of two things:
1)drive away like nothings wrong
2)studder and stall and ****/moan
If it does 1, it will start to do 2 shortly after, usually a minute or two into driving. This studder/stall behavior is usually accompanied by the fuel gague going wonky. This is typically demonstrated by the gague flicking from current fuel level to reserve, back up, somewhere inbetween etc while the car is on the fritz.
My dad and I are going to take some time to poke around the CE this weekend, and I dont want to be throwing parts (or other things if I get pissed) at it, so if anyone has any suggestions of where to look first, I would be eternally grateful.
Thanks homos
Thread Starter
MBWorld Fanatic!
Joined: Jun 2006
Posts: 4,968
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1990 300ce 24v I6
My dad did cap/rotor/plugs last time it did this, about 3-4 years ago. Can they get buggered that fast?
He put in all new cap, rotor, plugs (OEM), ignition wires, OVP, and ignition transitor. Or transitorized ignition module. or something to that effect.
He put in all new cap, rotor, plugs (OEM), ignition wires, OVP, and ignition transitor. Or transitorized ignition module. or something to that effect.
Last edited by Saijin_Naib; Nov 21, 2007 at 12:05 AM.
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MBWorld Fanatic!
Joined: Dec 2006
Posts: 1,042
Likes: 1
From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
It sounds to me like you're losing 12 volts to the ignition system intermittently. Definitely examine the OVP. I believe it supplies power to most of the ignition and control system. Also check all your fuses. I don't think the cap and rotor (wait, don't you have the early M104, HFM engine?) would cause the gas gauge to lose power. It sounds like a simple problem, but may be tricky to pinpoint. It might even be the ignition switch contacts. Try turning the key slightly to the left when it acts up and see if it changes anything.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2006
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1990 300ce 24v I6
Okay, its the CIS system. Not sure what to be specific.
So today, we took a look at the OVP (thanks shadow
) and the fuses tested fine. Next, we took out the MAS unit and cleaned the contacts, remounted it. Seemed fine. What is the box between the MAS and OVP behind the battery?
Next up, my dad took out the airbox and cleaned the throttle body to be sure it was not sticking.
Final step, turn the car on. Worked wonderfully for a while, then just ****ted out. Turns out that the fuel pump is pumping but stopping, leaving no unburnt gas in the tail-pipe when we cranked it to try and get it going again. Also, no fuel was felt going down the line from the fuel pump when we were cranking the car.
So what does this mean for us? Bad fuel pump, bad fuel pump relay? Or both?
Thanks!
So today, we took a look at the OVP (thanks shadow
) and the fuses tested fine. Next, we took out the MAS unit and cleaned the contacts, remounted it. Seemed fine. What is the box between the MAS and OVP behind the battery?Next up, my dad took out the airbox and cleaned the throttle body to be sure it was not sticking.
Final step, turn the car on. Worked wonderfully for a while, then just ****ted out. Turns out that the fuel pump is pumping but stopping, leaving no unburnt gas in the tail-pipe when we cranked it to try and get it going again. Also, no fuel was felt going down the line from the fuel pump when we were cranking the car.
So what does this mean for us? Bad fuel pump, bad fuel pump relay? Or both?
Thanks!
MBWorld Fanatic!
Joined: Dec 2006
Posts: 1,042
Likes: 1
From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
For what it's worth, a bad fuel pump usually doesn't just stop once it's already running. I would replace the relay if it were my car.
Newbie
Joined: Jul 2007
Posts: 20
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From: Rhode Island
Mercedes 300e 1986
The Relay is behind the batter, small black box with 6 cyl written on it, before you you can jump two of the pins to run the pumps, cant remember which ones though.. I just took my relay to bits and normally the solder goes on one of the points. Just resolder it and test again!
Thread Starter
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1990 300ce 24v I6
Okay. I need this confirmed. I see nothing around the battery that says 6 zyl or 6 cyl on it. I have read elsewhere that the Fuel Pump relay is integrated into the MAS. Is this bull**** or what? I have the MAS pulled right now and all thats left is the battery, the OVP, and another box with writing on it straight behind the battery if you are looking at the car dead on. wtf am I looking at here? I want to get the fuel pump relay out of the car like now, so I can get it re-soldered by a repair shop.
Help!!
Help!!
Thread Starter
MBWorld Fanatic!
Joined: Jun 2006
Posts: 4,968
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1990 300ce 24v I6
*** it guys, Im going with it. Im off to the repair shop now to hopefully get it fixed. I cant afford 300$ for a new MAS right now. Especially not if we dont get the 400e sold and my knives sold.
