Fuel system (tell me in not mad?)

Need technical Q/A then you're in the right place

Moderator: martauto

rix313
E30 Zone Team Member
E30 Zone Team Member
Posts: 4967
Joined: Fri Oct 31, 2008 11:00 pm
Location: Silverstone

Post Sat Sep 01, 2012 4:15 pm

I have been trying to get my newly fitted engine to fire. I have had a few chuffs etc from it and it's wanted to go but doesn't run for more than a couple of seconds.

Now I was a bit unsure as to whether I had the fuel lines connected to the rail the correct way. Turns out I didn't so I swapped them over and the car then stopped firing at all. I have recently fitted a new tank but used all the old pipe work and labeled them and took photo's when I removed them.

After some tests n such it seems that the return pipe is being pressurised by the pump. Now I realise that this sounds like a simple (well swap the ends over at the pump you donk :hammer: :hammer: ) question, however after tracing the lines from the engine back to the pump, I can't figure out what I've missed? The lines which run over the tank are bent and moulded in such a way that they can only go the way I have done them?

Here's the newly assembled tank on the floor:

Image


And here is the fuel pump and pipes:

Image


Can any one see anything I'm just plain missing? Is it possible the pump has thrown a wobler at all? (I didn't touch the pump I just removed it and put it in a bag).

Any input or ideas appriciated.
daimlerman
**BANNED**
Posts: 15968
Joined: Mon Feb 27, 2006 11:00 pm
Location: Grumpy Old Man

Post Sat Sep 01, 2012 4:43 pm

Swap the pipes at the engine bay end.
Youth is wasted on the young.
Jim320i
E30 Zone News / COTM Team
E30 Zone News / COTM Team
Posts: 10627
Joined: Sun Oct 25, 2009 11:00 pm
Location: Leicestershire

Post Sat Sep 01, 2012 5:01 pm

Plug those 2 plugs in? :D

Image
Grrrmachine
E30 Zone Wiki / Team Member
E30 Zone Wiki / Team Member
Posts: 8043
Joined: Sat Feb 09, 2008 11:00 pm
Location: Warsaw, Poland

Post Sat Sep 01, 2012 5:03 pm

You've not done something silly like put the fuel filter on the wrong way round, have you?
rix313
E30 Zone Team Member
E30 Zone Team Member
Posts: 4967
Joined: Fri Oct 31, 2008 11:00 pm
Location: Silverstone

Post Sat Sep 01, 2012 5:33 pm

Nothing in the engine bay has changed at all. It's all been at the tank end. I would change the pipes at the engine bay round however this would cause problems further back as the return pipe (currently pressurised) would become the main pipe and it A. doesn't have a bead on to hold the pipe under pressure (potential to blow off). B. the pipes it runs through are smaller so the flow is restricted.

I could swap the pipes where the tank pipes meet the chassis pipes however as mentioned before, they are formed in such a way they would not fit properly the other way round.

If any one could just confirm for me which of the pipes on the pump are supposed feed and return I think that might help?

:mad:
Sawyer_E30
E30 Zone Regular
E30 Zone Regular
Posts: 660
Joined: Mon Mar 03, 2008 11:00 pm
Location: Sittingbourne

Post Sat Sep 01, 2012 5:43 pm

Jim320i wrote:Plug those 2 plugs in? :D

Image
Yeah, it looks like there is no power to the pump.
E30: The only E-number you should be concerned about
Grrrmachine
E30 Zone Wiki / Team Member
E30 Zone Wiki / Team Member
Posts: 8043
Joined: Sat Feb 09, 2008 11:00 pm
Location: Warsaw, Poland

Post Sat Sep 01, 2012 6:00 pm

The Wiki only has a pic of a single-pipe pump. Don't know if that helps:

Image
SGP
E30 Zone Regular
E30 Zone Regular
Posts: 502
Joined: Thu Aug 31, 2006 11:00 pm

Post Sat Sep 01, 2012 9:33 pm

Surely the return pipe shouldn't be pressurized ?
If it ain't broke..
Fix it till it is :)
DanThe
E30 Zone Team Member
E30 Zone Team Member
Posts: 28647
Joined: Sat Sep 10, 2005 11:00 pm
Location: Staffs

Post Sat Sep 01, 2012 9:42 pm

Grrrmachine wrote:The Wiki only has a pic of a single-pipe pump. Don't know if that helps:

Image
You can see the blanked off return on the top of the plate next to the elec connection