DESPERATE for a solution, please help!

My 1984 500SEL V8(117 engine) suddenly cuts out in traffic after being run for a half hour to an hour. I was nearly killed yesterday at a dangerous intersection when she just quit! The car will not restart unless I remove the fuel pump relay and use a jumper between #7 & #8. Then it starts instantly. I replaced the transistorized spark unit because the manual says the fuel pump relay gets it's signal from the TD terminal. Also found a used relay and swapped that at the same time. When I took it for test ride, it cut out suddenly at an intersection and like I said, nearly got me killed. This car already has a new fuel pump and filter previously. I checked the female connections at the fuel pump relay, they seem fine. I know that it has to do with the fuel pump relay circuit since the jumper retarts the car by eliminating the function of the relay. I am at my whits end because the only way to test it, is to drive for awhile and it always cuts out suddenly in traffic. This problem started awhile ago when it would cut out occassionally but always restart in about five minutes. Luckily it never did it in traffic, but now it won't restart unless I use the jumper. Please help, as I live where you have to walk long distances even to go to the food store, and I'm sixty years old.

Woody:

There are a lot of past posts on this subject. I've posted at least a half dozen. You've started in the right spot -- Fuel Pump Relay. However, I would suggest replacement with a NEW unit. I had an '84 190E that did exactly what you describe. Turns out the stock FPRs were not hermetically sealed and subject to internal corrosion. This led/leads to intermittent contacts. The NEW, replacement units are sealed to prevent this from happening.

Good luck!

Brian16V

[tower]

I ran through a similar experience with an 88 volvo. You would drive around and the whole car would just die. The ultimate solution was in both the fuel relay and what volvo calls the "radio suppression relay". The fuel relay obvious what it does, but the radio suppression relay is actually a relay in the engine compartment controlling the fuel injectors. So that the radio doesn't pick up the rf of the injectors firing constantly, they run a lead to this relay from the key, and relay on the power to the injectors.

Both of these problems were pinned down to the little printed circuit board in the relay developing microcracks in the soldering. Solution is to reheat the existing solder to make if flow and generally the relay is 100% again.

Maybe want to give it a try. It is the true 2 cent solution. Look at volvo's www.brickboard.com you find some interesting information in the faq's that could apply to you.