Help Getting a 1989 300e Back on Road - PeachParts Mercedes-Benz Forum

lorainfurniture · #1 12-23-2012, 05:08 PM

You are very simply not getting fuel. Don't bother changing anything until you figure out why gas is not getting to the cylinder. Bad ovp will make the car run terribly, but run.

First, disconnect an injector line from the injector. Bend it up slightly to get a small cup or something to catch fuel. Stick a screwdriver or something to deflect the air "plate" as low as you can. Turn the key up until you start, but don't start.

It should squirt out a piss-like consistincy of fuel. If it does, you have clogged injectors, if it does not, then you have to start going backwards.

dh34 · #2 12-24-2012, 03:15 AM

Quote:

Originally Posted by stormyc88

Maybe try testing the fuel pressure? The pumps may be running but not creating enough pressure to crack the injectors, which take at least 60psi (I think)

Or maybe whatever gas was in there for the last two years went bad and gummed every injector or other part of the injection system(long shot)

Or maybe something with the ignition switch is disrupting power to the fuel pumps when you turn the key to "start" versus "on" (here's that voltage check you mentioned)

At the very least, if there was no stabilizer in that gas when it was parked, I would drain it somehow and put in fresh gas with techron or seafoam. Todays gas with ethanol in it does not last!

I'm no expert, but I hope this helps
Im sure others will chime in with plenty of ideas, this is a great forum!

-Chris

I syphoned most of what was left of the old fuel and then a fair amount of ugly old gas drained when I changed the fuel filter. I put fresh fuel in prior to the first start attempt. I disconnected the fuel line prior to the fuel distribution system and there was pretty good pressure when the key was turned.

Quote:

Originally Posted by lorainfurniture

You are very simply not getting fuel. Don't bother changing anything until you figure out why gas is not getting to the cylinder. Bad ovp will make the car run terribly, but run.

First, disconnect an injector line from the injector. Bend it up slightly to get a small cup or something to catch fuel. Stick a screwdriver or something to deflect the air "plate" as low as you can. Turn the key up until you start, but don't start.

It should squirt out a piss-like consistincy of fuel. If it does, you have clogged injectors, if it does not, then you have to start going backwards.

I disconnected the line at the injectors. The line was wet, but not streaming when the key was turned or starter engaged. My question is - is there a single input or valve that would prevent the fuel distribution system from allowing fuel to the injectors? I want to make sure there is no vacuum line or simple check this before I replace the fuel distro.

I appreciate y'all taking the time during the holidays to help with this.

Dan

Gilly · #3 12-24-2012, 05:01 AM

Your original statement that this eliminates the fuel pump relay as the problem is wrong. If you give it a squirt of fuel (ether or whatever, something flammable) and it fires, it means you are not getting fuel, so you more than likely have a fuel pump issue, the pump itself or the relay. You can "jump" the relay easily and see if it runs, then you know.

MORE than likely NOT the OVP because the car WILL run without the OVP, just not very well.

For a car sitting a long time the pump may be seized, sometimes a tap with a hammer (on the electrical motor itself) will unstick it.