Hi,

I have a 1987 300E, completed tuned up and replaced two fuel pumps last month because the car has been neglected excepting adding water and oil. The car starts fine however when the speed is gradually increased 20-25 mph the car would hesitate then pick up the speed, the engine rpm would increase from 2000 rpm to 3000 rpm then drop down to 2000 rpm, after that it seems fine without any problems. When returning home, I have to drive up a slightly short steep hill, the car would, sometimes, behave the same and hiccup 3-4 times when I press the accelerator along the climb. Do I have the similar problems, as posted this thread #16215 and I should check vacuum leaks and adjusting the fuel mixture and EHA?

Approximately how much would it be costing me if I let a mechanic, specializing in Mercedes but not from dealers, to do the work? Certainly I hope my problems have nothing to do with the transmission.

DL

seems like a clogged fuel filter based on my experience. with mine.

Since the car has been neglected, it certainly wouldn't hurt to replace the fuel filter, but there is a myriad of things that could cause this problem. I would start by disabling the EHA and see how it runs.

Lift up the passenger side carpet and disconnect the Oxygen sensor connector that is under there. Inspect this connection closely before you do, as this connection being bad could even cause this problem if shorted with water or something.

If disabling the EHA has no change, then you need to check fuel pressure and check out the ignition system.

If you can't do this yourself and you decide to find a shop, make SURE that they have experience with the CIS injection system. It is a different breed of cat than the vast majority of electrically fired injector systems on modern cars.

Hope this helps,

Also the classic symptoms of a failing air flow sensor.

Make sure that the tech who works on it has specific experience with these problems on this model or you will end up a thousand bucks poorer with a new fuel distributor that did not solve the problem.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Hi, all:

Thank you all for the advice. Although I'm so un-tech but I feel better when I bring the car to a shop and I may act like I do know what I'm talking about. It's really interesting, I stumbled on to this forum by chance and I'm amazed about the advice that I have received so far.

DL

Thanks to all again. Here are two dumb questions:

1. What is EHA?

2. Where is/are fuel filter(s)? The two fuel pumps were replaced last month since bother of them were leaking, so I was told. Were the fuel filter supposed to be replace when replacing the pumps?

DL