duluth 41 Report post Posted May 8, 2023 Hi all, I have a 2002 e39 530i. I had not driven it for a month or so and when I went to start the car it would crank, start, then immediately die again. Scanned it and got P0102 (low voltage for MAF). Unplugged maf/cleaned maf- same result. Any ideas where to start ? Quote Share this post Link to post Share on other sites
BM WORLD 1258 Report post Posted May 8, 2023 dead fuel pump ? fuel pump relay ? how much fuel in the tank ? massive vac leak ? intake boot split ? Quote Share this post Link to post Share on other sites
duluth 41 Report post Posted May 8, 2023 50 minutes ago, BM WORLD said: dead fuel pump ? fuel pump relay ? how much fuel in the tank ? massive vac leak ? intake boot split ? About a quarter tank. No split in the intake boot. Will check fuel pump/relay. Thanks Quote Share this post Link to post Share on other sites
BM WORLD 1258 Report post Posted May 8, 2023 29 minutes ago, duluth said: About a quarter tank. No split in the intake boot. Will check fuel pump/relay. Thanks check for constant fuel supply when cranking , one common issue on these is syphon tank system seals/orings failing so when quarter tank and below it wont suck fuel from left side of tank try adding some fuel to the tank then see if it starts and runs or check if rhs is empty but still has fuel on lhs the green fuel relays often fail on these in the boot and fuel pumps die also with age etc (and sucking air from running on empty) 1 Quote Share this post Link to post Share on other sites
