How to check for fuel Pump problem 88 260E
 

My car does not start. A couple days before it quit working for good, it would die while driving then restarted after like 10 minutes. I do not hear the fuel pump come on when I turn the ignition key. Before I change the fuel pump out, how do I know for sure it is the fuel pump or relay? I see that there are 2 pumps for this model. Where do I look for the chassis number? Thanks.

You can hot wire the fuel pump to run without the relay as a test, this is usually the easiest, although it doesn't contain any diagnostics for the inputs to the relay, it'll definitely tell you the pumps are good and the engine is capable of running. The 2 sockets are the middle 2 across from each other, near the plastic centering pin (on the relay side). The fuel pump relay is the one that DOESN'T say "KLIMA" on it, it's the one that says "6 Zyl" and an RPM, which is the safety cutoff rpm.
Gilly

Thanks for the reply. I am sorry but I don't know much about cars. Could you please explain to me in easy steps on how to hotwire the fuel pump? Thx.

i'm sorry.but if you dont undrstand nothing,than should we post pictures .Sorry i think the best way to repair your car is maybe to bring it to a shop.We could tell you how to do it,but if you do it wrong than you might screw things up more than you have now

Thanks, Gilly. I did as you recommended and the car started. It was the relay that malfunctioned rather than the fuel pump. I want you to know I appreciate it.

Meangrean, although no thanks to your negative post, you challenged me to do what I thought I couldn't do.

Chris

I was about to order a new fuel pump relay, however, I saw another post here talking about putting some new solder over the old on the back of the pump relay post (post 30 I think). I tried it and it worked perfect. The old solder looked like it was craking a bit. I just put some new solder on the top and I guess that helped with the heat exchange. It saved me the cost of a new pump relay. I can't believe it was so easy to do. Few months back, when I was driving my 1999 320E, it suddenly died on the freeway. Then, I waited a while. The car restarted but died again while driving. I towed it to the dealer and they charged me over 500 dollars to fix it. I am now sure it was the same problem. Thanks you guys for the help.