Thanks Arthur.. I dont have a fuel pressure gauge installed on this car. My other cars all have pressure gauges installed in the fuel lines.

Going to the store to pickup one tonight.. What type of reading should I expect...

Im now thinking that I have triggered a non-ODBII fuel shutoff code when I spilled gas everywhere. What you think?

You are thinking too much..
Take a FP reading and see what you have ...if the reading drops off , you have a fuel problem..if it doesn't , you have a possible ignition problem .
If their is no ignition on HFM/SFI systems, the injectors shut down for cat protection.
Do a FP test............and check your wire harness...

FP specs for 104/HFM :

At idle
3.2-3.6 bar with vac line connected to FP regulator
3.7-4.2 w/o vac
2.5 bar after 30 min shut down of engine, key OFF.

okay.. I know Im thinking too much.. but nothing has worked..:confused:

Purchased the Fuel Pressure tester. Hooked it up to the test port and got a reading of 7 psi. Had someone turn the car on and turn start the car. Nothing changed. Needle didnt move..

What next?

<<Had someone turn the car on and turn start the car. >>

turn the car on and turn start the car ?????...

you want to tell me what that means

Yep.. someone turn it on and then tried to start it.. It ran for 2 seconds and died...
no fuel.. Freaking 8 month old fuel pump is fried?

But the relay is switching it off!

My question was ..What does "turn the car on and turn start the car ..." mean ??

Are you telling me Key ON , engine OFF 7psi, and then same with engine running????

What does "turn the car on and turn start the car ..." mean ??
Turn the key to on and turn the key to start.. turn on ignition... But it has spark and no gas..

Okay.
The pressure is remaining the same at all key positions: off, on, start. It runs until gas is gone: 2 seconds..

I just drained all of the pressure using the pressure kit.. And did the test over.. All 3 positions: no pressure... and no run this time...

What do you think is going on? Im not experienced with MB's. But Im willing to learn. Im taking off work tomorrow and hopefully fix this (while the MB parts shop is still open). So, what are your recommendations...

Check fuses first..give them a spin.

The ecu needs a TN speed signal to operate the FP relay..
..but you want to check the FP and filter for flow by themselves ..so, make a jumper wire with a fuse in-line and jumper pins 87 and 30 at the FP relay connector while you have the gauge on the fuel rail..do not run the car, just run the pumps so you can verify that side of the fuel delivery..you should see 3-4 bar pressure and it should hold after you remove the jumper.........
....if still low/no pressure , the problem is FP or filter. If pleanty of pressure, then the relay is not seeing a TN signal and dropping the pump circuit..could be a poor connection at fuse feed to ecu , unplugged cam sensor, or bad OVP feed to ecu...tap the ovp a few times ,, the fuse can look fine , but the OVP can be bad and that will cause no feed to ECU, which in turn means no feed sigto FP relay.
Isolate/verify pumps w/jumper first...

Thanks. I will post my results tomorrow morning..

On the Jumper wire, what size fuse, 30amp?
Pin 30 has 12v constant (even with the ignition off). Just connect the jumper to the relay pins or to the actual connector base holes?

This may seem like a stupid question, but is there any gas in the tank? Maybe you lost it all on the garage floor!

Richard could be correct.

I would add at least 2-3 gallons of fuel before going any farther

Richard & Doc..
The tank is 3/4 full.. Plenty of gas.. But thanks for asking..

You can have a good reading BUT still be low on fuel on the pick-up side of the tank.

Don't be fooled.

The W202 chassis has 2 sending units. 1 can give a bad reading.

Good point Doc.. Leaving now to pickup 5 gallons of gas to add.. And I will start testing within an hour.. Conference calls all morning.. :rolleyes:

Testing Update.
1. Added about 4 gallons of fresh fuel. Tank is now full

2. Checked the Fuel filter for blockages.
Results: Looked clean (changed 8 months ago with pump)

3. Checked the FP with a fused jumper wire and gauge on the fuel rail. Ignition off.
Results: Gauge went to 54psi and could hear fuel returning to the tank. Removed jumper. The test gauge leveled off to 50psi after 5 mins and holding.

Now, Im checking the relays again. New FP relay installed yesterday & fuse is new.
I do have a backup OVP relay in my box somewhere. Will install and test for OVP failure.

Where is the Cam sensor located?

New Update: After 30 minutes, the fuel pressure has dropped to 42psi. Im loosing pressure slowly. Would the injector seals cause this?