Fuel Pump Relay

[mrclean]

Hi, on my 85 735i I'm trying to jump out the fuel pump relay because in order to test the injectors I need pressure in the lines. However, it tells me to jump out pins 30 and 87 on the relay, but the book doesn't tell me where it is located, so....I'm wondering if anyone here knows where that is located and possibly have a diagram, because I want to know if I have a bad injector before monday, and to see if my bad vaccum line has been causing all my problems that I found upon tearing the whole fuel system apart. I know I should have found it earlier, but I just found the one under the throttle assembly when i was pulling off the fuel rail. So any replies are appreciated.

[bryan1970]

why not just crank the engine? is ther something preventing you to do that? it just seems like that would be an easier route to get pressure in the lines. and by bad injector are you looking for a leaking injector or just one that doesn't work period?

but to give you help on your question i don't know exaclty which one it is but i think the relay is in the fuse block under the hood.

[Dirty_Tool]

Im asssuming you cannot crank the engine because you are removing the fuel rail and are going to do a leakdown test on the injectors correct? Here is a picture of the location for the fuel pump relay but the picture is very poor. I cannot seem to find a diagram for the circuit but if worse comes to worse then you can just power up the fuel pump directly. Also in case I do find a schematic, what transmission do you have, auto or standard?

DT

[mrclean]

I don't want to crank the engine because when I was pulling 2 of the injectors out I believe the little plastic cap on the end of the injector tip came off and fell into the hole, so I don't want to lose it to the compression of the cylinder. 4 of them still had the cap but 2 didn't, so I want to possibly pull of the intake and see if it fell in. Is this cap on the end of the injector important, or is it just a heat protector that won't affect performance. I want to check all the injectors before I go and pull off the intake. I'm checking for a leaky injector, and one that is either plugged or just plain not working, because i've been having a misfire problem that was not solved by cap, rotor, wires and plugs, but they did help. But I'm still having bogging down problems, a fairly stable but rough idle, and it sometimes misfires even at higher rpms. i already checked compression and it was fine, so I don't suspect a head gasket problem, so I'm checking the injectors to see if one is all gummed up or firing improperly. Oh, and Also, its a manual, I wouldn't have gotten it without it.

[mrclean]

Thank you for that diagram, exactly what I needed.