Argh! Fuel pump issues...

[paulh]

so my 99 has been leaking fuel basically since i got it, not enough to really be concerning, but enough that you noticed it. so a month or so ago i decided that i should replace the lines going from the external fuel pump to the tank since they looked really bad. well that pretty much made things worse, and ive avoided fixing it till tonight. i thought the issue was that i hadnt gotten a good seal at the fuel pump, due to shitty hose clamps and some non fuel injection rated hose. well i thought wrong, it seems that the pump is leaking! not much, but a pretty steady pace, from some sort of silver metal bit by the outlets of the pump. so, since i have a snowballs chance in hell of finding a spare fuel pump (of course i didnt buy a spare when i could have at carlisle! ) anybody have suggestions on how i can fix this mess? i know later gas tanks wont fit my car, so i suppose that is out, and im kinda at a loss for ideas. anybody have a spare d-jet fuel pump kicking around?

Paul

[Jordan]

I was talking to Luke last weekend about switching tanks with the '74 (which was d-jet) since they don't have the internal pump (which I wouldn't need for carbs). If I understand the conversation right even though the suspesion points changed slightly in the rear '73+ , the rear floor is the same? (I'm still not 100% sure) so a later tank should fit fine, it's just the internal vs. external fuel pump on CIS vs. d-jet. and I;m not sure how that will play out.

Also, I'd ask him about a fuel pump from that car...he already has the tank out.. it is probably still attached somewhere.

[paulh]

I was talking to Luke last weekend about switching tanks with the '74 (which was d-jet) since they don't have the internal pump (which I wouldn't need for carbs). If I understand the conversation right even though the suspesion points changed slightly in the rear '73+ , the rear floor is the same? (I'm still not 100% sure) so a later tank should fit fine, it's just the internal vs. external fuel pump on CIS vs. d-jet. and I;m not sure how that will play out.

Also, I'd ask him about a fuel pump from that car...he already has the tank out.. it is probably still attached somewhere.

yeah i think all the later 2door tanks will fit, but not the 3 door ones, or any 900 ones obviously. i forgot that car was djet, ill have to shoot Luke a PM about that pump. im thinking also i might be able to disassemble the pump and reseal it, but thats iffy at best. if all else fails im probably just going to rig up a bosch pump from a mercedes or jaguar, as they have external fuel pumps too.

Paul

[Jordan]

Yeah the 3-door ones have the filler on the other side..and then the trunk floor pan changed after 80 (IIRC).

[paulh]

ok, i've fixed it, it seems that the o-rings in the thing failed, probably due to the 10% ethanol fuel that its been getting that it was never designed for. the 3rd port on the fuel pump seems to be some sort of over pressure bypass valve that the fuel pump can return fuel to the tank with if needed. seems like one of those weird early EFI things that they dont do anymore. what i did was use a newer bosch roller fuel pump from a 900t mounted in the same location as the original pump, lines hooked right up to it, and i just stuck a bolt in the 3rd line, which is now unused. car runs great, i can replace the pump when it goes bad, and you cant even tell that its been modified once its all installed. and best of all, the inside of the car wont constantly smell like gas now :lol:

Paul

[DeLorean]

good ideas I come up with, eh? Now granted, Paul WAS the one who actually fixed it and figured out what to do with the mystery 3rd line, but I did suggest "just sticking a newer bosch roller fuel pump in it"

[Geoff]

and best of all, the inside of the car wont constantly smell like gas now :lol:Paul

Unless, like me, you eat lots of beans and spicy food!

[paulh]

heres some pictures of the bosch pump installed, wrapped it in gorilla tape and it fits right in the clamp that the old pump was in :lol:



cant even tell its not stock!



Paul

[paulh]

also, a fun side note, that fuel filter you see there...there wasnt one before, seems that the previous owner didnt see that as neccisary, and he had eliminated it :lol: to his credit though, he did rig up some sort of weird pressure gauge inline with the fuel pump, presumably to test the fuel pressure, but it didnt work, he probably had it on the wrong port or something :lol:


Paul

[GRMPer]

So, as a confirmation, a 77 tank would fit a 74? (both 2doors) Does the 74 have the round access holes like the 77?

It might be easier to fix the 77s tank (with it's newish fuel pump) rather than flush the varnished/rusted 74 stock tank.

Per

[Luke]

The 77 tank would fit in, but you wont have the access holes in the rear floor for the intank fuel pump. You could either cut one or build an "metal plug adapter" that same diameter as the fuel pump that clamps inside the large rubber bootie on 77 tank and adapts to external lines and pumps.

[GRMPer]

Yea, I pulled the tank tonight...it's crustacular inside...the 77 may make more sense to fix that one hole vs a lot of sealing. I'll take it by the shop that does gas tank repairs tomorrow.

looks like there's a lot of lines going to/fro in the 74, the 77 is simpler in comparison, although larger. I'll probably have to lengthen those turnbuckles that bolt it in.

Yea, it's a diversion, but I've got about 2 months before Odie can get its cage...

[paulh]

Yea, I pulled the tank tonight...it's crustacular inside...the 77 may make more sense to fix that one hole vs a lot of sealing. I'll take it by the shop that does gas tank repairs tomorrow.

looks like there's a lot of lines going to/fro in the 74, the 77 is simpler in comparison, although larger. I'll probably have to lengthen those turnbuckles that bolt it in.

Yea, it's a diversion, but I've got about 2 months before Odie can get its cage...

yeah lotsa lines on the djet cars, theres a return from the fuel rail on the top of the tank, a large feed out of the tank to the pump, then a small line going to the fuel rail, and then the third line off the pump goes back into the tank, seemingly some odd overpressure device.

Paul

[GRMPer]

Ok, the tank guy said to use the 77 tank, not the 74, so I'll be converting to an intank pump and simpler lines. Also need to get longer brackets to fit the 77 tank (the original 77 brackets were rusty, the 74s are a little short)

next up, see why there's no sparky. positive/negative sides of coil are both positive..so maybe the points or coil are toast...I'll investigate this afternoon.

Per