Hard Start for 1987 560SEL

[American28]

Thanks for any help. I have reviewed alot of the other posts before I posted hear without finding clear applicable help.

Recently my 1987 560SEL has been sometimes hard to start. This happens about 1 in 10 times starting and all the other times it starts fine. Usually I have always held my foot off of the accelerator and turned the key and it would start right up beautifully. Now sometimes it will not start after cranking for 5 to 10 seconds. Then if i put my foot on the accelerator and it will always start but seems bogged down or flooded for a few seconds and will smoke slightly and have a weird almost sweet smell to the exhaust (but not a gas smell). As stated, all other times it starts fine. I dont recall this happening more or less during first start up or cold days or after a long drive, it just happens whenever. I sure would appreciate any help. Thanks!