not2fast

My 2012 GL550 has become slow to start after sitting for more than a day. I feel it is something to do with the fuel pressure as it seems to prime and then run fine.

I have read to change the fuel filter since it has a valve in it. I don't see any gas on the ground under it, but do smell gas after bringing it home that goes away a day or 2 later.

Any ideas?

DarthVaderpa

Slow start is caused by either weak/discharged battery or a "bad" starter. If the fuel pump fail or has a clogged filter, the the engine will rotate but it won't start.

not2fast

It is not the batter or starter. Those work fine. Once it starts I can shut it off and it starts instantly.

I will probably start with the pump and filter.

DarthVaderpa

I had a similar issue. I replaced both fuel pump and sensor and later found that the starter was not providing the adequate torque. Sometimes the engine turn slow, sometimes it start instantly. After replacing the starter no more slow starts.

not2fast

Interesting. Yeah. I can drive it and go away an hour and it starts up instantly, but if it sits overnight it feels it needs to prime the fuel line.

DennisG01

I don't think a starter or battery would cause the gas smell, though. Maybe a leaking injector?

not2fast

That is the strange thing. I feel something is causing the release of fuel pressure. I am guessing to find a leaking injector I would start by pulling the plug.

DarthVaderpa

I had "intermittent" slow start for a while. The the fuel pump failed and got it replaced. The gas smell as well as a weird fault code (P0446 Evaporative Emission Control System Vent Control Circuit Malfunction) happened after replacing the pump. Shortly after that the level sensor failed. I guess that there was a loose vent line. After replacing the pump, the sensor and clearing the fault as well as the gas smell the slow start got worst. I got the starter tested and found that it did not meet the torque requirements. I got the starter replaced and problem solved.

not2fast

So starter fixed fuel smell? Did you have the same issue on restarts within an hour of starting it for the first time for the day?

Mine doesn't seem to be intermittent. I know when it will be hard to start.

DarthVaderpa

the fuel smell was fixed after replacing the sending unit. Before replacing the starter I has the same issue on restarts. I thought was the battery, but got the battery tested and found OK.