98 ML320 No Start - No Fuel - Page 2 - PeachParts Mercedes-Benz Forum

360glass · #16 01-03-2005, 06:15 PM

The wheel well liner that needs to be removed in order to change the fuel filter....I just can't get the darn thing off.....the cap for the fuel pump was easy.....

Ric,
Ann Arbor
2000 ML320, 118k

sdanville · #17 01-04-2005, 02:27 PM

All I can tell you is..if I did it, you can do it.
double check that ll the fasteners are clear and work it and bend it until it clears. I did it twice.
I replaced the filter 1st then the pump a week later.

I had to take the seat back out to tighten the big gas pump screw.
it leaked the 1st time.

360glass · #18 01-05-2005, 04:50 PM

OK then....I thought it would come out easy...Thanks...

Carlisle · #19 02-14-2005, 09:02 PM

I was going crazy. I upgraded/replaced the fuel filter using the instructions from the TSB and then while the truck started (no leaks) the fuel gauge was dead. I went to work inspecting the contacts at the fuel pump, which were a bit corroded. Cleaned them up and then the car would not start, no fuel, no fuel pump sound. I tried everything; from the pump back but I had no power. First at the pump and then at the wiring connection, which is inside the left rear, wheel well. Finally I check power at the fuse #38, NADA.

I re-read this thread, which suggested a similar problem, which determined the pump, was bad. MPLAFLEUR had no power at the fuse, so he jumped the contacts at the relay. First I had to determine which contacts, #5 and #3, they are the 2 biggest ones. I checked everything with a voltmeter and continuity tester first. I shorted the contacts and pushed in the relay. I then had power at the fuse. Still no pump, I was dejected and going to give up, call the tow truck. Then all of a sudden I heard the pump come on. I never touched the key. It just started on its own. I then removed the jumper from the relay, reinserted the relay and everything works. Again the fuel gauge is out, but I will live without it until I can have the dealer look it over.

I still do not know why the problem solved itself. I am suspicious of the computer/ignition, which did not give power to the fuel pump relay, but worked after the truck was started, stopped, and the jumper taken off.

This thread saved me. Thanks all.

mplafleur · #20 07-11-2005, 10:30 PM

It look like just over a year and 30,000 miles, the pump failed again.

Sheesh, the original did better than that.

I am going out and verifying again.

mplafleur · #21 07-18-2005, 08:24 AM

Uneeded replacement on my part.

The truck started later, so I was unable to determine what the culprit was. Having replaced the fuel pump and filter last year with simalar symptoms, I called Phil and ordered a new pump. Replaced it and the wife drove the M-class a couple of days, maybe it was one. It died again after leaving church while I was hefting trusses up on my new garage.

Bringing a load of tools to the gas station 20+ miles from home, I tried, but my wife ran the battery down as she'd been sitting in the hot sun for over an hour. I turned blower motor and the key off and set about looking around. I pulled the brass cap off the fuel rail. I did have some fuel, but no sure how much is expected in a hot soak engine. It kind of bubbled out. I brought a timing light, so I put that on and asked my wife to crank the engine. I didn't see any flashes immediatley but then saw some and the truck started up. Hmmm. That's great. Another intermittent.

A couple minutes later the truck stalled. I put the light back on. No flashes, therefore no spark. This must be a CPS problem. The ECU must need CPS to determine crank. If it doesn't see the crank, it won't turn on the fuel pump nor will it trigger spark.

Looks like another parts order.

sdanville · #22 07-18-2005, 09:06 AM

I too replaced my fuel filter and pump before replaceing my CPS to fix my on off engine.

I'd bet a 6 pack you can fix it fast.
you need a good torx socket - i bought mine at NAPA.
$60 +- for the part and I have been rolling for many many months.

there are two listed for My ML320, I just remember 1st I ordered the more expensive one and it didnt fit, the cheaper one fit.

mplafleur · #23 07-18-2005, 02:24 PM

I just called Phil and told him to ship it.