Have an issue with an S500 that's driving me nuts.

Car is owned by an older gentleman and friend who is not computer literate. Came to me because I own a 560SL and asked for help knowing I got my MB going because of great help from the forum.

Car started with a warm stall issue. Live in rural Alabama far away from the big city, so he took it to a local indie who it seems never saw a german car before. he replaced injectors, fuel pump, plugs, and fuel filter. Naturally, none of which helped. Now it's my problem.

Operating temp and 2000 rpm stall made me change the fuel pressure regulator first. (After checking fuel pressure first).

No help. Car will fire and then immediately die.

128k on the clock so thought regulator was a good bet.

Need to be pointed in the right direction before I cost my friend more money.