Hello, I just picked up a new project to tinker on :o) Its a 1983 320i that I bought from the original owner. Its been sitting in a carport in town for the last few years and has not moved. (he says it was running 6 months ago) Fuel does not have a bad smell from what I can tell.
I replaced the battery and positive cable and the engine turns over, just wont fire up.
From my research, there are 2 fuel pumps on these cars? One in tank with the sending unit and one under the rear of the car next to the fuel filter. When I crank, I think I can hear the one in tank cycling.
So I got under the car and it looks more like two fuel pumps and a filter? Are these both fuel pumps?
File Jul 16, 6 37 51 PM.jpg
Last edited by JoeBeemer; 07-16-2017 at 06:40 PM.
The pump is on the left, the thing on the right maintains fuel pressure when you shut the engine off, preventing vapor lock... can't remember what it's called.
The external pump (pictured) is quite loud on mine... loud enough to hear inside the car. If it's sat for a while, I'd bed there's rust and sediment in the tank... might want to pull the in-tank pump/fuel level sensor unit and take a look inside the tank. I ended up having to drop the tanks and have both acid cleaned.
Last edited by steide; 07-01-2017 at 03:50 PM.
Awesome, thanks for the reply. Ive already got the back seat out, so Ill check the tank to see how they look inside.
How hard are the tanks to drop if I need to do that?
I don't remember it being too difficult... a couple retaining straps. Be careful on the bolts, don't want to strip them. If memory serves, I dropped them together, then separated them once on the ground. It's been a few years since I did it, though.
one pump, 1 accumulator, 1 filter
Here a pic of the car :o)
IMG_3246.jpg
Last edited by JoeBeemer; 07-16-2017 at 06:34 PM.
no the accumulator does not need to be replaced unless the internal diaphragm is leaking. to test pull the small black hose off the accumulator and run the fuel pump, if gas comes out then it's defective.
why do you feel the need to change the pump. the pump is triggered by a signal from the negative post of the ignition coil and not by the key. the best way to test the pump is to bypass the relay. pull the relay out of the socket and using a jumper wire connect socket # 15 (power from fuse 3) to # 87 (pumps). this has to be done with the key in the run position because fuse 3 is only hot when the key is "on"
Last edited by Tom D; 07-02-2017 at 04:11 PM.
Tom D
77 e21 - m42
88 e30m3
04 330 dinan3
84 r1000rt
02 r1150rs
all of them gray
14 f800gsa - red headed stepchild!
Have you tried starting fluid first?
Spray some starting fluid in the air filter intake, then crank for a few seconds. if it doesn't sputter at all, then you have an ignition problem. if it sputters and dies, then you have a fuel problem, continue with testing the pump. you can also rent a fuel pressure tester for free (with a refundable deposit) at most auto parts stores.
Is that a cloth braided hose on the accumulator? If it's never been replaced, it's probably seeping fuel and allowing the external fuel pump to suck air bubbles. Same with the other two pieces of suction hose that connect to the metal "Y" fitting on the suction side of the external fuel pump.
Tbd
Nothings ever easy...lol Im trying to pull the in tank sending unit and pump. Why cant I get this thing out?? I can lift it and move it around but does the pump have to be unbolted to get proper clearance? See pics below..Looks like a rusty metal tube on one side and pump housing on the other. ughhh.
IMG_3577.jpgIMG_3576.jpg
Bookmarks