inspect water separator/fuel filter

[tolsen 630]

I wonder what pressure is in the fuel combo filter? While it's working, I mean, not just at-rest pressure.B .... wheels turning again ...

2.5 bar gauge pressure.

[dukemon 0]

[

Just had my Smartie in to Pugs in Edmonton to check out a 'lack of power' at the top end of the shift. Car starts and runs normally but when anything more than normal acceleration is required [ie anything 2800 rpm or over] the car will not give you anything extra no matter how hard you press on the accelerator. Neil threw it on the scanner there because I did have a 'check engine' light. He though it would be the egr valve but the scanner indicated that the trouble was with the high pressure end of the fuel pump... something to the effect that the pressure was to high. Read all the posts on the fuel filter/water seperator and wondering if this is maybe whats causing me grief. Unless Mercedes replaced it under warranty that filter has never been replaced and Im coming up on 175000 k now.

[MikeT 744]

I would have thought it'd be causing lower pressure if it was partially blocked....the high pressure pump is the more likely area to look - perhaps the rail pressure limiter is malfunctioning. Didn't the shop have any ideas to pursue?

[dukemon 0]

[He must have somebody he consults regularly in Germany because he said he was going to have a chit-chat with them. Said He'd never seen this problem before.

[tolsen 630]

Perhaps yours has a remap? Remaps can cause fault codes like too high pressure.

[dukemon 0]

Nope never had a remap...... maybe its just an issue with the rail limiter as Mike suggested or a sensor connected to the fuel pump?

Edited November 12, 2012 by dukemon

[dukemon 0]

Well there is nothing that a thousand dollars cant fix..(well maybe there are somethings). Finally took the Smartie to David Morris in Edmonton. Their scanner gave them the same code as Neil at PugCity was getting. They must have seen something like this before because they did some troubleshooting and found a wire in the rear wiring harness that runs along the rear bumper to the fuel pump that was either showing no conductivity or higher than normal conductivity. Anyways it was a defective wire that had a kink in it. They called me partway through the repair to say they had to take the rear bumper off to get to the wire. They quoted me at about $540 total for the repair....I kinda though ah well thats not so bad....is it? I showed up the next day to pick up the car and was presented with a bill for $934 and some cents. ..... Im not gonna say anymore! I paid it, left the dealership and then phoned the service manager to express my serious annoyance. He agreed it was not a good way to conduct business and that is the last I've heard from them. Gotta go get my door-handles replaced under warranty later this month...looking forwards to that.