Starting problem with 1981 Mercedes 380 SL


#1

Experienced a problem this week, car started but immediately died and would not restart. 36 hours later tried again with same result. Only 89K miles, fuel pump replaced a year ago. Any suggestions? Captain Ed


#2

This should be a CIS injection model so after offering my heartfelt condolences in your time of grief, the first step with running problems on a CIS car is to run the fuel pressure checks.

These are specialized tests requiring a specialized pressure tester and someone who is familiar with CIS; a blight upon the face of the Earth if there ever was one. If not a Benz guy someone familiar with older VWs, BMWs, or Volvos would work as the principles are the same.

There’s a number of wild guesses that could be made but pressure checks are the beginning.


#3

Captain Ed

Have you tried bridging the fuel pump contacts at the relay, which is . . . I believe . . . located between the glove box?

I’m just throwing it out there, because the fuel pump relays often fail on those older Benz cars with CIS

Here’s another idea . . . the idle air control valve might be bad. I distinctly remember a 380SL in excellent condition that wouldn’t stay running . . . because the fuel pump relay AND the idle air control valve were bad. Interestingly enough, the bad parts were new aftermarket parts. After replacing them with genuine Benz parts, all the problems were resolved

I’m sure it couldn’t have been your car, because this car had 160K miles

The first thing I would do is make sure the fuel pump(s) are getting power and ground. They’re readily accessible when you crawl under the car. Should be near the rear axle


#4

Thanks. Sent an email to Messer Motoren Werke in Richland, WA to set up an appointment.


#5

Is that a Benz independent shop?