500 SEC died, need help to resuscitate - PeachParts Mercedes-Benz Forum

#1 02-04-2003, 09:48 AM

Driving home yesterday, for about 2 minutes the car ran really rough, no power, then died. Can not restart. Most of the fuel system in this car is new: fuel pumps, fuel distributor, fuel pump relay, idle control box, idle control valve, fuel filter, fuel injectors, also new ovp. Could this problem and symptoms be related to the ignition coil? How do i check? It just cranks and cranks with no result. Also, a lot of noise that seems to be coming from the cruise control box (I think! Box on front of motor with a lever coming out of it going to throttle body.). Could the cruise control box affect anything?

Steve Gutman · #2 02-04-2003, 10:47 AM

Were there any other noises or anything? It could be a coil, ignition control module, or many others.

What noises come form the cruise control? I don't think the cruise control could be causing your problems but if it arcing from that area it could be something else. I don't know how to check the coil. Anyone?

#3 02-04-2003, 11:38 AM

No other noises, just the cruise control box, making a rapid clicking sound.

#4 02-04-2003, 04:02 PM

What is the easiest way to check for fuel to the injectors? Pull the lines of at the injectors to see if fuel flows out? or is there another way. Forgive my lack of technical skills!!!

#5 02-10-2003, 10:15 AM

Checked for spark, very little. Changed ignition coil, distributor cap and rotor, excellent spark now. The problem seems to be with the fuel pump. Intermittently comes on and off. Checked the fuel pump relay by jumping to bypass but pump still intermittent. My question is, and this may sound stupid, does this car have one or two fuel pumps?

Steve Gutman · #6 02-10-2003, 10:32 AM

If your fuel pump is old, they do fail and need to be replaced. Replace the filter while you're at it. I have to admit that I don't know if they are supposed to run intermittently or not, but I don't think so. There is a bypass for the fuel so I think it runs continuously. How many miles on the car?

#7 02-10-2003, 10:38 AM

283,000 miles. Engine rebuilt @ 210,000. The fuel pump relay did go about 6 months ago and i replaced it with a new one. I bypassed the relay and the fuel pump exhibits the same behavior as with the relay installed. Its not a steady on/off either. Very irratic, comes on for a second, goes off for 10 seconds, comes on for 5 seconds, off for 2 seconds, and so on. Does the same thing with or without the relay installed. I can only tell what is happening with the pump by listening, and there is no fuel pressure at the the injectors. Do you know how many pumps this car has?

Steve Gutman · #8 02-10-2003, 02:35 PM

Your car has only one fuel pump. THe thing next to the fuel pump that sort of looks like it is a fuel filter.

Noticing that you recently replaced the fuel pump, I am not sure why it could be failing. Did you run 12 V straight to it? If the pump is running intermittently I think it's bad. You must have spent a lot. You say you got a new fuel distributor. Did you replace it yourself? This is a bit of a mystery.

#9 02-10-2003, 02:45 PM

Thanks for the info on the pump. The distributor is new, well, refurbished, but my technician put that on along with most of the other fuel system parts. I replaced the fuel pump relay, as it was just a matter of pulling the old one out and putting a new one in the slot! I also replaced the idle control box, idle control relay, they were easy too. The fuel pump was a rebuilt one, so maybe it had a defect. Good to know there is only one, lot less money to spend!!! Funds are dwindling away with this car, but, it is well worth it. Love this car! Seeing as a fuel pump costs about $200, i think i'll just have it replaced. What could the labor cost? $100 maybe? not really an in depth job is it?

Steve Gutman · #10 02-11-2003, 03:01 PM

You could change it yourself. It is pretty simple. I can't go throught the procedure now but If you try it, use a flourescent trouble light so gas doesn't spray a hot bulb.