djfelip

Hey guys,

I wanted to see if I could get a little help from the master mechanics on this forum. I took my 2001 CLK 430 into the shop today to get check engine light diagnosed. It came back with two codes p0170 and p0173 which are fuel trim issues. After running a star diagnosis the tech informed me I have an under performing fuel pump.

I was given a summary of the work to be performed and I wanted to make sure this sounded correct because this was not a dealer I took the vehicle to.

Replace Fuel Pump - $786.10
Replace Fuel Pressure Regulator - $302.10
Replace Fuel Filter - $143.90

That was the run down of parts to be replaced excluding labor rates so that’s pure parts costs. I have been doing a bit of research on my own and was able to locate the pump & filter at http://www.germanstar.net/208f.htm.

I have been unable to locate a fuel pressure regulator, I was told it was not installed from the factory but it is in fact part of an old recall on the fuel pumps. Is the FPR a separate unit from the pump or is it internal?

I plan to order and replace the parts myself but I want to make sure I am replacing everything with the correct stuff.

Thanks,

redcoupe

Most times with those codes its the Mass Air Flow sensor.

Ausmbtech

Sounds more like the Air Mass Meter as previously stated.

Secondly, the fuel pressure regulator is actually in the fuel filter. Not sure where your tech thinks it is..........

If you had a fuel pump problem then you'd really know about it. I've only seen a few late model pumps fail and none of the cars started except one, that one stalled as soon as it was put in gear.

djfelip

I am going to clean the Mass Air Sensor and see if that fixes my problem before I replace the fuel components.

I do notice a loss in power, I was told that the output from the pump was lower than it should be. He also told me that he tested the pump output before and after the filter and the output was the same. That would indicate to me my fuel filter is fine but I am going to replace it anyways if I end up replacing the pump. I will let you guys know what happens I might end up making a DIY guide for the fuel pump.

Thanks for the help any other suggestions would be greatly appreciated.

redcoupe

Just cleaning the mass air flow sensor wont fix the problem, you need to replace it and reset self-adaptations.

lkchris

Ditto.

You do not need a new fuel pump and indeed the regulator is in the fuel filter which you can feel free to replace--just be sure you use new OE clamps.

You need a new mechanic.

djfelip

Ok quick update on this one. It was the fuel pump that was the problem i had the output tested. I just finished changing it and the filter out. How do I property reset the self adaptations and the ecu? I cannot currently get it to idle more that 20 seconds.
Thanks guys,