Looking for insight on placement of fuel filter and pump. I know there are varying opinions, front or back but here is my twist and want to see what anyone thinks. It’s okay if you question my thinking.
To bring you up to speed, I have the entire fuel system removed and just installed stainless fuel lines from Tangerine. I’m thinking about placing the fuel filter up under the tank and leaving the fuel pump in the rear. I just ordered a Bosch 69133 pump to replace the original one. So this changes routing the fuel lines to two ports, one on each side of the pump verse three on one end of the pump.
The hard lines come into the engine bay facing towards the passenger side which does not provide enough room to place the filter then the pump without looping the fuel lines.
I’m trying to think how to keep things neat and simple.
I’ve attached a picture of the pump mounting location, original to the car. Please share your thoughts and ideas. If someone is really for mounting everything up front under the tank, I’d like to see some good pics . That seems like that could get crowded and hard to work on later. Just having a filter up there with a bit of extra hose, I’m thinking I could easily pull that through the 6” hole to change without much hassle. Thanks, MikeClick to view attachment Click to view attachment
Full Version: Placement of fuel filter
Nice work, looks good and clean in your car !
I did recently change the 3port to a 2port. Fuelpump and filter both in the back, and I 'looped' the line. . Still tidy enough for me, since it fits there with the other stuff and not in plain sight.
In my post you see the longer fuelline because of that loop
http://www.914world.com/bbs2/index.php?showtopic=345333
I did recently change the 3port to a 2port. Fuelpump and filter both in the back, and I 'looped' the line. . Still tidy enough for me, since it fits there with the other stuff and not in plain sight.
In my post you see the longer fuelline because of that loop
http://www.914world.com/bbs2/index.php?showtopic=345333
QUOTE(Frankvw @ Jun 25 2020, 01:19 AM) 
Nice work, looks good and clean in your car !
I did recently change the 3port to a 2port. Fuelpump and filter both in the back, and I 'looped' the line. . Still tidy enough for me, since it fits there with the other stuff and not in plain sight.
In my post you see the longer fuelline because of that loop
http://www.914world.com/bbs2/index.php?showtopic=345333
Great information. Thank you.
keep the loops as long and easy as you can - but keep them fixed close to the longitudinal (if you go for 72-74 fix of FP to longitudinal). its hard to do.
my theory is the fuel likes to vaporize if the loops or bends are too tight.
(yet to prove that in a hot aus summer so have to see if i have them loose enough).
the back loop out of the fuel pump is hard one with the two port FP - unlike og three port which had all the lines come out of one end (pointing towards rear) - that allowed the FP to sit close into the corner.
a tight fit with the two port in the 72-74 location given its got lines coming out of either end.
the pump is mounted in my car with the out side to injectors pointing to front of car - so we could still mount a filter before the pump in orig location. that makes the loop out a tightish one as its trying to get back and go towards rear of car.
when i ran the car in the 90s/early 00s never had vaprization problems with the og set up - and aus is hotter than cali in summer.
wish icould still buy an og three port pump as it suits the amount of space available for lines. but its an outmoded design and i get that.
looks to me like you have early fuel pump mounting location off rear firewall.
i believe this location had the most problems with fuel vapor lock.
just the same it would let you do a simple linear run of filter, pump and pressurised exit out the other end.
what i describe above for 72-74 gets more complex.
my theory is the fuel likes to vaporize if the loops or bends are too tight.
(yet to prove that in a hot aus summer so have to see if i have them loose enough).
the back loop out of the fuel pump is hard one with the two port FP - unlike og three port which had all the lines come out of one end (pointing towards rear) - that allowed the FP to sit close into the corner.
a tight fit with the two port in the 72-74 location given its got lines coming out of either end.
the pump is mounted in my car with the out side to injectors pointing to front of car - so we could still mount a filter before the pump in orig location. that makes the loop out a tightish one as its trying to get back and go towards rear of car.
when i ran the car in the 90s/early 00s never had vaprization problems with the og set up - and aus is hotter than cali in summer.
wish icould still buy an og three port pump as it suits the amount of space available for lines. but its an outmoded design and i get that.
looks to me like you have early fuel pump mounting location off rear firewall.
i believe this location had the most problems with fuel vapor lock.
just the same it would let you do a simple linear run of filter, pump and pressurised exit out the other end.
what i describe above for 72-74 gets more complex.
to assist.
a pic from when i was halfway through forming metal fuel lines on mine.
(you can see how far i am stretching my metal fuel lines across firewall in contrast to USA steel line set ups - but i have a rhd car with some different problems to negotiate).
you have to be careful looking at this pic because it is a rhd converted car,
ignore the handbrake cables you can see swooping out of firewall.
( i could not ignore them of course as i had to get around them).
lhd cars don't have that!!!
what you can see in this photo are the og plastic lines still clipped to rear firewall and heading right to where fuel pump is located (inclusive of the original clips that held the plastic lines to firewall.
this is a 74 car.
my car does not have the metal clip off firewall you have in your photos which i assume must be to mount a pre 72 fuel pump.
i have also posted pic from factory manual showing 72-74 fuel pump location. (you can see how hard it is to get a fuel line out the back of a two port fuel pump - the og pump was jammed right up in corner). the factory manual i have does not show the earlier fuel pump location. (other guys can correct me if i am wrong but i believe they did a recall on 914s and moved the fuel pump to the post 72 location - but probably left the original bracket there).
if what you have is a pre 72 with the pump bracket, (what i think i am seeing in your photo?) then the piping should be a breeze (maybe). its a straight shot.
you do a fuel filter at end of steel pipes and pre pump. its a low pressure filter.
BUT
(but i notice USA steel line kit isn't giving you a lot of room at end of steel tube pre mounting point for fuel pump if that bracket is the fuel pump mount).
to consider - if you do the og pre 72 mount of fuel pump (if that is where it went), then you might get the original back in the day vaporization problems.
as suggested in previous thread.
you def. want a filter before the pump.
that is the original set up and it stops the crap that might come in from the tank. but if you want to be cautious, you can also have a high pressure filter after the pump to save your injectors (tending towards unobtainium) from the pump detonating its innards if it goes wrong, if you are retaining the injector set up.
i hope the factory manual photo makes sense of the tricky fit for the two port modern pump set up when you come to the 72-74 location.
the guys advocating a later 75-76 set up make a lot of sense.
its way less problematic given you cannot get the original pumps any more.
i contemplated it.
and almost did it.
and might yet, if the loop i had to make out of the back of the two port pump gives me problems in the summer.
i just tried to be as close to original as i could. not sure why now, given how much i had to change in the end.
i possibly could have done it differently by mounting my pre pump filter off the rear firewall before the pump and then shot the pressure feed out of the other end of pump.
but i committed to the pre pump filter in the og location for 72 -74. and i moved the FP slightly rearward of where it was jammed into corner of longitudinal and rear firewall - to get the line out of the back of the pump.
i did my post pump filter in the engine bay. there was no room left below.
Click to view attachment Click to view attachment
a pic from when i was halfway through forming metal fuel lines on mine.
(you can see how far i am stretching my metal fuel lines across firewall in contrast to USA steel line set ups - but i have a rhd car with some different problems to negotiate).
you have to be careful looking at this pic because it is a rhd converted car,
ignore the handbrake cables you can see swooping out of firewall.
( i could not ignore them of course as i had to get around them).
lhd cars don't have that!!!
what you can see in this photo are the og plastic lines still clipped to rear firewall and heading right to where fuel pump is located (inclusive of the original clips that held the plastic lines to firewall.
this is a 74 car.
my car does not have the metal clip off firewall you have in your photos which i assume must be to mount a pre 72 fuel pump.
i have also posted pic from factory manual showing 72-74 fuel pump location. (you can see how hard it is to get a fuel line out the back of a two port fuel pump - the og pump was jammed right up in corner). the factory manual i have does not show the earlier fuel pump location. (other guys can correct me if i am wrong but i believe they did a recall on 914s and moved the fuel pump to the post 72 location - but probably left the original bracket there).
if what you have is a pre 72 with the pump bracket, (what i think i am seeing in your photo?) then the piping should be a breeze (maybe). its a straight shot.
you do a fuel filter at end of steel pipes and pre pump. its a low pressure filter.
BUT
(but i notice USA steel line kit isn't giving you a lot of room at end of steel tube pre mounting point for fuel pump if that bracket is the fuel pump mount).
to consider - if you do the og pre 72 mount of fuel pump (if that is where it went), then you might get the original back in the day vaporization problems.
as suggested in previous thread.
you def. want a filter before the pump.
that is the original set up and it stops the crap that might come in from the tank. but if you want to be cautious, you can also have a high pressure filter after the pump to save your injectors (tending towards unobtainium) from the pump detonating its innards if it goes wrong, if you are retaining the injector set up.
i hope the factory manual photo makes sense of the tricky fit for the two port modern pump set up when you come to the 72-74 location.
the guys advocating a later 75-76 set up make a lot of sense.
its way less problematic given you cannot get the original pumps any more.
i contemplated it.
and almost did it.
and might yet, if the loop i had to make out of the back of the two port pump gives me problems in the summer.
i just tried to be as close to original as i could. not sure why now, given how much i had to change in the end.
i possibly could have done it differently by mounting my pre pump filter off the rear firewall before the pump and then shot the pressure feed out of the other end of pump.
but i committed to the pre pump filter in the og location for 72 -74. and i moved the FP slightly rearward of where it was jammed into corner of longitudinal and rear firewall - to get the line out of the back of the pump.
i did my post pump filter in the engine bay. there was no room left below.
Click to view attachment Click to view attachment
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.