[ladybenz300e]

ok,i'm completely new to this, my car 1986 300E won't start at all, I don't even know where to start. It seems like it's not getting fuel or something. Can anyone advise me on how to diagnose the problem? I'd rather figure it out myself then go to a shop and get ripped off because I'm a woman.

 

[jhodg5ck]

To start, do you hear any humming/hissing from the right rear of the car when you turn the key on (lower the rear window)?

Jonathan

 

[ladybenz300e]

To start, do you hear any humming/hissing from the right rear of the car when you turn the key on (lower the rear window)?

Jonathan

nope

it starts sometimes and sometimes it does not. In my honda, I had a similar problem, and it was just the main relay.

 

[RBYCC]

nope

it starts sometimes and sometimes it does not. In my honda, I had a similar problem, and it was just the main relay.

Check the fusing at the OVP relay.
It's located behind the battery.

Blown fuse or bad relay can cause the symptoms you are realizing !

 

[jhodg5ck]

OVP won't cause the pumps not to run.. I'd say pull your FPR behind the battery (it will have your RPM limit written on it) and jumper sockets 7 & 8.

Jonathan

 

[jmoney6]

that snot true in my 93 300e 4-matic with the OVP disconnected the car will not start. Check the OVP its to the right of the battery a box with 2 fuses on it. If you find that this is the problem do an E-bay search for on. I just picked one up for 15 dollars new.

 

[Jrs2000]

We all made the assumption that the car is turning over. If the fuse on the OVP is in order than check fuel pump relay.

Start by pulling the relay and jumpering sockets 7+8 (3rd top and bottom over from the passenger's side).

You should hear the fuel pumps run, they aren't very quiet.

If they run, you next check is to turn the key to position two and checking the voltage between socket 9 and 11, it should be battery voltage.

If that is proper chances are your no-start problem is the result of a bad fuel pump relay. You can get them on Ebay used for roughly $15 and new for $80. If you go to the dealership they will run you upwards of $200.

My car has been off the road for almost a month because of a bad fuel relay. I bought one on Ebay and the guy couldn't find it. He finally "found" it and the one he found and sent me wasn't the one I ordered. I let him know that it wouldn't work and he has been looking for it for 3 weeks now.

I finally got sick of waiting for that guy so I bought another one from Ebay and specifically told the guy I wanted that exact part number. I get the relay and he sent me a A/C relay. They both sent me another one today so hopefully I'll get it going by next week. By the time these idiots are done I'll have a small collection of relays.