*** Fuel issue(s) ***

[mgburg]

I'll try to keep it as short as possible...

XFIL's funeral in Decatur, IL.. Taking the Xwife and son to see dad/GP get "dusted off" into the wild-blue-yonder (Air Force Vet/Cremated). While approaching Bloomington/Normal, I'm hearing the fuel-pump (FP) whirring away...just south of B/N, the car spazzes, then slows down to stop...engine not running...try to start it...sounds like no fuel. I get out, remove the emergency 1 gallon of fuel from trunk, pour into tank, replace container, get in, VAROOM! We're on our way! (Problem with the fuel gauge not reading correctly? Hmmmm...) Nope...about 2 miles from I-74 on the N. side of Decatur...dropping off...spazzing...dead again...this time with a full tank (filled up after the emergency fill)...fuel pump? OH EF'N GREAT!!! Spent Saturday/Sunday trying to locate a fuel pump, "located" one from some parts store that asked ALL THE RIGHT QUESTIONS AND GOT ALL THE RIGHT ANSWERS and the pump that shows up has some thingamabob on the O/P end that looks like an elongated nut that a specialized-bolt has to pass through a connector that crimps onto the fuel hose that the other end is attached to a similiar connector that attaches the same way to the EXTRA-LARGE fuel filter...woo! Anways, it's decided to try to limp 350 miles back to La Crosse Sunday night/Monday morning on the off-chance the fuel pump wasn't just "over-heating" and spazzing out on its own...nice decision...we get home about 12-midnight Monday morning...no tow-jobs...just drove an 1-1/2 at a time, took a 15-30 minute break, started right back up and drove to the next time interval...

The following morning...a car-sized puddle of fuel under the Benz (Thank God it was parked outside on the concrete!) Believe it or not, I waited a week before I took the car to the "nearest" Benz dealer in WI., up by Wausau...turned out to be the fuel-line coming into the fuel pump via the "accumulator" - so, about 212USD later, I was out of there...but I still experienced (I failed to mention this to begin with) the slow, 5-10 seconds of cranking before the engine fires and stays running...it's the same whether the engine is warm or cold...

TWO DAYS LATER: Another puddle!?!?!?! I look under (puddle isn't AS large...) and I notice it coming from the O/P side of the FP area...so I call the Wausau Benz, then I drive up there again and find out that the other hose, feeding to the engine itself, is cracked and seeping...another 185USD, I'm on my way back...performance is ENHANSED!!! I'm climbing hills, not "saturating" at 85mph...I'm able to hit 90mph and I still have pedal travel left...COOL!!!

BUT...the dreaded 10-second cranking gremlin is still w/me...

Now, it's less than 35° F., and I couldn't get the damn thing started unless I "squirted" some raw fuel into the throttle-body (TB) area under the air filter cover...and once I got it started and shut it off, it won't start again...she's parked in the driveway, slightly askew from straight in...it's driving me nuts...it looks like I was "tipsy" when I got home...all in the dang daylight!!!

Am I looking at leaking vac-lines for the vac-advance? Did the FP finally pump its last? Is the accumulator finally not? Is there some set of relays that aren't doing their job? I don't hear the FP when I switch the key to Position 2...not even for a fraction of a second...and if there are relays, where the heck are they located???

FYI: This is a 1977 280E, 123.033.12.021xxx body, w/the M110.984.12.016434 engine...she probably (odometer is stuck on 115,115) has around 150,000 miles on her...any logical, orderly way to go through this before I "flat-bed" her to...

H E L P !

[BENZ TEK]

I am assuming that you are talking about your 280. I would change the fuel pump check valve and fuel accumulator. The problem you are having is that after the car sits a while all of the fuel drains back to the tank instead of staying up at the engine. Thats probally why you have the 5 to 10 seconds before the car starts. The systen has to prime itself in order to get enough fuel pressure through the fuel distributor to the injectors. Also check to see if the fuel distributor is leaking fuel into the bottom of the intake. After a while they leak past the orings. Remember the injectors are pressure operated!! They will not open untill enough pressure is registered. A fuel guage connected in line would be great right about now to see if the pressure is dropping after you turn the car off. Good Luck!!

[mgburg]

BT:

Where can I get a fuel guage to check the pressure?

And, the accumulator...that's the piece just before the FP's I/P, right?

[BENZ TEK]

Originally Posted by mgburg

BT:

Where can I get a fuel guage to check the pressure?

And, the accumulator...that's the piece just before the FP's I/P, right?

You will have to find a guage from a mercedes repair shop to properly check it out. You will need to hook the guage in line ( T into the line) to check for fuel pressure drop. you need to be able to monitor it to see how fast it drops. Also you are correct on the accumulator!! That is the location. It is silver.