SL/R230: 2008 SL550 low fuel tank causes misfire
Thread Starter
Newbie
Joined: Sep 2018
Posts: 9
Likes: 0
From: Fort Lauderdale, FL
2008 SL550 with 83,000 miles
2008 SL550 low fuel tank causes misfire
2008 SL550 low fuel tank causes misfire. This problem only happens when the fuel gauge goes under 1/4 tank. Dirty fuel tank?
Thread Starter
Newbie
Joined: Sep 2018
Posts: 9
Likes: 0
From: Fort Lauderdale, FL
2008 SL550 with 83,000 miles
Also, after the misfires the check engine light goes on. Scanner code reads, spark plug or coil are bad. Restart the car and the check engine light goes away.
If it is a weak fuel pump then why would the car fly when the gas gauge is full or 1/2+ full. This situation only happens when gauge is 1/4 or less. Could the gas gauge be malfunctioning, showing 1/4 tank yet be closer to zero fuel left?
If it is a weak fuel pump then why would the car fly when the gas gauge is full or 1/2+ full. This situation only happens when gauge is 1/4 or less. Could the gas gauge be malfunctioning, showing 1/4 tank yet be closer to zero fuel left?
Last edited by dsmall7777; Sep 9, 2018 at 12:54 PM.
Senior Member
Joined: Jul 2015
Posts: 355
Likes: 41
From: amarillo texas
2003 sl 500
misfire
If your scanner can ID a specific plug the easiest thing to do is change it out, perhaps the fuel filter too and see if condition improves. I sort of want to go with Rodney on this that the fuel pump may be low on pressure. It may be possible to test it for proper pressure when tank reaches 1/4 full or less and see if that is the real problem.
moretech
moretech
MBworld Guru
Joined: Dec 2009
Posts: 10,782
Likes: 1,011
NO LONGER ACTIVE
Yes - that's what I'd so - check pressure and current draw with a full tank, and then again at < 1/4 when it starts to run poorly. Pressure at the fuel rail should be 53-60psi. Current draw should be 10-16 amps.
