1989 300e starting problem
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1989 300e
1989 300e starting problem
1989 300e (109k miles) won't start. If I pull the fuel pump relay it will start and run until it runs out of gas ( about 5-10 seconds) I then put the fuel pump relay back in, and it wont start, after a few cranks I pull the relay out and it starts again until it runs out of gas again (5-10 seconds)
Is this a bad relay? I have second one I got from a junk yard from a 300e with 150k miles and it does the exact same thing?
Any ideas?
Also, what is the other relay behind the fuel pump relay for?
Is this a bad relay? I have second one I got from a junk yard from a 300e with 150k miles and it does the exact same thing?
Any ideas?
Also, what is the other relay behind the fuel pump relay for?
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1989 300e
I went through all the steps in fuel pump relay schematics troubleshooter and it all tests out good. I had already metered the OVP on the bench but just checked the socket to make sure it's getting juice, which it is and it is clicking when you turn the key to the on position, so I believe the OVP should be ruled out.
When I bypassed the fuel pump relay with a 12v feed, the fuel pump does turn on constantly ( doesn't cut out) but she doesn't start either but if I remove the 12v feed she starts until it runs out of gas in the cyclinders (5-10 seconds), back to square one
. What is that telling me?
I appreciate your time as I'm pulling my hair out over here
When I bypassed the fuel pump relay with a 12v feed, the fuel pump does turn on constantly ( doesn't cut out) but she doesn't start either but if I remove the 12v feed she starts until it runs out of gas in the cyclinders (5-10 seconds), back to square one
. What is that telling me?I appreciate your time as I'm pulling my hair out over here
Junior Member
Joined: Jan 2007
Posts: 66
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From: San Diego
German Taxi (1987 300E)
I went through all the steps in fuel pump relay schematics troubleshooter and it all tests out good. I had already metered the OVP on the bench but just checked the socket to make sure it's getting juice, which it is and it is clicking when you turn the key to the on position, so I believe the OVP should be ruled out.
When I bypassed the fuel pump relay with a 12v feed, the fuel pump does turn on constantly ( doesn't cut out) but she doesn't start either but if I remove the 12v feed she starts until it runs out of gas in the cyclinders (5-10 seconds), back to square one. What is that telling me?
I appreciate your time as I'm pulling my hair out over here
When I bypassed the fuel pump relay with a 12v feed, the fuel pump does turn on constantly ( doesn't cut out) but she doesn't start either but if I remove the 12v feed she starts until it runs out of gas in the cyclinders (5-10 seconds), back to square one
. What is that telling me?I appreciate your time as I'm pulling my hair out over here
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Joined: Dec 2006
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From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
Sounds like it's flooding out, for sure. Try disconnecting the cold start valve and see what that does. It could be stuck open or energizing when it shouldn't. Also make sure the Air Vane (the flapper thingy under the fuel distributor) is resting on its stop and not stuck.
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1989 300e
I have come to to conclusion its flooding also...
I have swapped out the following one by one and still have the same results...
*injectors(including sleves and gaskets) brand new
*new plugs, wires, d-cap and rotor
*cold start valve has been unplugged and I disconnected the line to the distributor and plugged it to get it out of the loop
*Ignition module has been swapped 3 times same results
*fuel pressure regulator has been swapped twice same results
*fuel distributor swapped twice same results
*EHA valve swapped with distributor same results
*OVP has been metered and working fine/ pulled out at one time and still same results/ also swapped for the hell of it
*I've metered all pins to the fuel pump relay and all is working order according to the schematics..
*unplugged the o2 sensor/ same results/ plugged back in
I'm running out of ideas... and starting to pull my hair out..
I have swapped out the following one by one and still have the same results...
*injectors(including sleves and gaskets) brand new
*new plugs, wires, d-cap and rotor
*cold start valve has been unplugged and I disconnected the line to the distributor and plugged it to get it out of the loop
*Ignition module has been swapped 3 times same results
*fuel pressure regulator has been swapped twice same results
*fuel distributor swapped twice same results
*EHA valve swapped with distributor same results
*OVP has been metered and working fine/ pulled out at one time and still same results/ also swapped for the hell of it
*I've metered all pins to the fuel pump relay and all is working order according to the schematics..
*unplugged the o2 sensor/ same results/ plugged back in
I'm running out of ideas... and starting to pull my hair out..
Super Member
Joined: Sep 2006
Posts: 659
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From: New Jersey
1989300CE(sold),1996Accord,02CBR954
I have come to to conclusion its flooding also...
I have swapped out the following one by one and still have the same results...
*injectors(including sleves and gaskets) brand new
*new plugs, wires, d-cap and rotor
*cold start valve has been unplugged and I disconnected the line to the distributor and plugged it to get it out of the loop
*Ignition module has been swapped 3 times same results
*fuel pressure regulator has been swapped twice same results
*fuel distributor swapped twice same results
*EHA valve swapped with distributor same results
*OVP has been metered and working fine/ pulled out at one time and still same results/ also swapped for the hell of it
*I've metered all pins to the fuel pump relay and all is working order according to the schematics..
*unplugged the o2 sensor/ same results/ plugged back in
I'm running out of ideas... and starting to pull my hair out..
I have swapped out the following one by one and still have the same results...
*injectors(including sleves and gaskets) brand new
*new plugs, wires, d-cap and rotor
*cold start valve has been unplugged and I disconnected the line to the distributor and plugged it to get it out of the loop
*Ignition module has been swapped 3 times same results
*fuel pressure regulator has been swapped twice same results
*fuel distributor swapped twice same results
*EHA valve swapped with distributor same results
*OVP has been metered and working fine/ pulled out at one time and still same results/ also swapped for the hell of it
*I've metered all pins to the fuel pump relay and all is working order according to the schematics..
*unplugged the o2 sensor/ same results/ plugged back in
I'm running out of ideas... and starting to pull my hair out..
what about fuel mixture has anyone tickered with it?
Last edited by bjay51d; Mar 1, 2007 at 03:13 PM.
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Thread Starter
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1989 300e
and no the fuel mixture hasn't been tinkered with, due to my understanding that is set from the factory and shouldn't be tinkered with.. why you got an idea?
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Thread Starter
Newbie
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1989 300e
I have a new discovery.....
I had already checked the EHA valve but I previsously didn't check the socket if it was getting juice or not.. well I metered it and it was only getting 4 volts!!
So I ran a 12v feed to the EHA valve and the CAR STARTED with the FUEL RELAY IN!!!!! BUT stalls after 5-10seconds...
so now the car starts if I run a 12v feed to the EHA but it stalls after 5-10 seconds if I leave the 12v constantly or remove it...
What is that telling me? Computer? If so which computer controls the fuel system?
I had already checked the EHA valve but I previsously didn't check the socket if it was getting juice or not.. well I metered it and it was only getting 4 volts!!
So I ran a 12v feed to the EHA valve and the CAR STARTED with the FUEL RELAY IN!!!!! BUT stalls after 5-10seconds...
so now the car starts if I run a 12v feed to the EHA but it stalls after 5-10 seconds if I leave the 12v constantly or remove it...
What is that telling me? Computer? If so which computer controls the fuel system?
Super Member
Joined: Sep 2006
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From: New Jersey
1989300CE(sold),1996Accord,02CBR954
No you actually sound way more inclined mechanically than me.I was just saying you might want to check into it...
Newbie
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1989 Mercedes 300e
1989 Mercedes 300e
My cars lights would flash like the anti theft system had been activated. Never made any sounds and well now it won't crank. We have disconnected the anti theft module and still can't get it to start. I don't know what else it could be.
Newbie
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1989 300e
Mmadrid07, Mine just started doing the same thing. Turn the key, all the lights come on but will not crank at all. Battery is good. I keep trying for a few minutes then it started. Next day same thing, I put in in neutral and it started. I'm afraid to go anywhere with it. How do you disconnect the anti theft module?
Super Member
Joined: Jan 2015
Posts: 920
Likes: 46
From: Worcestershire UK
W124 260E
Sorry to say but been through this , mine was the immobiliser .Removed all of it to get her up and running again. Check-first- With none runner i would check out the Crank Possition Sensor first switch on spin engine over and look at the rev counter ,can you see the pointer in the revcounter move at all .No movement tells us that cps is shot. Other thing is the FR fuel relay you used did that work before in the other car before you fitted in your car socket .You can have a dud number 2 relay
Newbie
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From: Auckland NZ
1987 W124 300E
W124 300E starting problems.
1987 300E K-jetronic without Oxygen Sensor. 200,000km's. Car cranks OK, starts and sounds good but only runs for a few seconds. It's not flooding, its running out of fuel. I disconnected each pump in turn and both are working. I tried starting it with a jumper so the fuel pumps ran all the time but there was no change. I tried it with and without the cold start valve connected, same problem. Removed the CSV, plugged the hole on the inlet manifold, connected the CSV up but no spray when cranking. Disconnected the electrical plug at the valve and ran 12v directly to the valve, it sprays fine. Idling valve cleaned and working. Tried adjusting the mixture screw in the top of the fuel distributor to make it run richer but no change. put the adjuster back to the original setting. Found a comment when I searched Bosch for the basic or initial setting of the mixture screw. It said remove one of the pipes in the top of the fuel distributor and adjust the mixture until the fuel was just entering that port; it made no difference.
Still cranks, fires and stops and I've run out of swear words in English, French and Dutch!
The crazy thing is that I was under the bonnet tinkering when it suddenly stopped running.
There is a huge number of people out there who have experienced the same problem, (no, not the swear word one) you would think an answer would be easily available.
As you can see I've not replaced anything yet; I'll start with the Control Pressure Relay or "Warm-up Relay" as it is sometimes called.
Still cranks, fires and stops and I've run out of swear words in English, French and Dutch!
The crazy thing is that I was under the bonnet tinkering when it suddenly stopped running.
There is a huge number of people out there who have experienced the same problem, (no, not the swear word one) you would think an answer would be easily available.
As you can see I've not replaced anything yet; I'll start with the Control Pressure Relay or "Warm-up Relay" as it is sometimes called.
Super Member
Joined: Jan 2015
Posts: 920
Likes: 46
From: Worcestershire UK
W124 260E
As said in my post that the crank possition sensor may be up the creek .You can play for hours with out the right checking equipment and you wont find the problem .Switching wires out ,can damage the electronics making things worse. I have a chart that might help if you need to do it yourself.
Newbie
Joined: Jan 2016
Posts: 10
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From: Auckland NZ
1987 W124 300E
1989 300e starting problem
I haven't tested the pressures yet because I noticed something when I adjusted the mixture a little bit toward the rich side (clockwise). I touched the flap sensor, pushed it down a little, and I heard a "click". Is that normal?
Super Member
Joined: Jan 2015
Posts: 920
Likes: 46
From: Worcestershire UK
W124 260E
selector switch
Mmadrid07, Mine just started doing the same thing. Turn the key, all the lights come on but will not crank at all. Battery is good. I keep trying for a few minutes then it started. Next day same thing, I put in in neutral and it started. I'm afraid to go anywhere with it. How do you disconnect the anti theft module?
