I think I've read every topic here on moving the fuel pump forward and replacing the plastic fuel lines with steel (Including Clay Perrine's excellent write-up). Here are some things I'd like to know that I haven't seen anyone address:

1. Some folks use 3/8" and 5/16" lines. Some use 3/8" only. The factory lines are two different diameters, but does it really make any difference? Have the folks who have used 3/8" only had any problems?

2. Where have you put your fuel filter after the move?

3. How have you modified the wiring for the new location? Did you just extend the existing wiring up through the tunnel to reach the front location or did you rewire to draw power from the front of the car?

I'm about to do this project and want to make sure I get what I need. Summit is an easy source and they carry both sizes, but I'd prefer to buy just one 25" coil if it will work.

No problem with using only 3/8" except that the outlets on the bottom of the early tanks are two different sizes and the small one goes to the small line. So you have 3/8" hose going to a 5/16" outlet on the tank.

I had the fuel filters under the tank. You want your filter before the pump to avoid damage to the pump.

I extended the wiring from the back to the front when I did my green car.

QUOTE (ErnieDV @ Jan 23 2005, 10:23 PM)

I think I've read every topic here on moving the fuel pump forward and replacing the plastic fuel lines with steel (Including Clay Perrine's excellent write-up). Here are some things I'd like to know that I haven't seen anyone address: 1. Some folks use 3/8" and 5/16" lines. Some use 3/8" only. The factory lines are two different diameters, but does it really make any difference? Have the folks who have used 3/8" only had any problems? No problem, 5 years, 3/8ths line to front. 2. Where have you put your fuel filter after the move? 3. How have you modified the wiring for the new location? Did you just extend the existing wiring up through the tunnel to reach the front location or did you rewire to draw power from the front of the car? I'm about to do this project and want to make sure I get what I need. Summit is an easy source and they carry both sizes, but I'd prefer to buy just one 25" coil if it will work.

I think I've read every topic here on moving the fuel pump forward and replacing the plastic fuel lines with steel (Including Clay Perrine's excellent write-up). Here are some things I'd like to know that I haven't seen anyone address:

1. Some folks use 3/8" and 5/16" lines. Some use 3/8" only. The factory lines are two different diameters, but does it really make any difference? Have the folks who have used 3/8" only had any problems?

No problem, 5 years, 3/8ths line to front.

2. Where have you put your fuel filter after the move?

Front by the pump. Home Depot.
3/8ths flexible copper (I feel that my oil fired furnace uses it, it works for me)

three wire wrapped in plastic, look in the bulk wire area.
Fuel filter is the same

Put a barb on the end of the coper tubing to ensure that the rubber stay in place.
Use screw type clamps to connect rubber to copper

Good luck

Rich

QUOTE (r_towle @ Jan 24 2005, 12:29 AM)

1. Some folks use 3/8" and 5/16" lines. Some use 3/8" only. The factory lines are two different diameters, but does it really make any difference? Have the folks who have used 3/8" only had any problems? No problem, 5 years, 3/8ths line to front. 2. Where have you put your fuel filter after the move? 3. How have you modified the wiring for the new location? Did you just extend the existing wiring up through the tunnel to reach the front location or did you rewire to draw power from the front of the car? I'm about to do this project and want to make sure I get what I need. Summit is an easy source and they carry both sizes, but I'd prefer to buy just one 25" coil if it will work. [/QUOTE] I think I've read every topic here on moving the fuel pump forward and replacing the plastic fuel lines with steel (Including Clay Perrine's excellent write-up). Here are some things I'd like to know that I haven't seen anyone address: 1. Some folks use 3/8" and 5/16" lines. Some use 3/8" only. The factory lines are two different diameters, but does it really make any difference? Have the folks who have used 3/8" only had any problems? No problem, 5 years, 3/8ths line to front. 2. Where have you put your fuel filter after the move? Front by the pump. Home Depot. 3/8ths flexible copper (I feel that my oil fired furnace uses it, it works for me) three wire wrapped in plastic, look in the bulk wire area. Fuel filter is the same Put a barb on the end of the coper tubing to ensure that the rubber stay in place. Use screw type clamps to connect rubber to copper Good luck Rich

Copper lines are a very BAD idea for fuel lines. Copper will work harden and crack (can you say "fuel leak"), and the soft copper lines sold in hardware stores for water lines will start flaking internally when exposed to gasoline. BTDT.

As for the fuel filter, put one in front of the pump under the tank. You can use a carburetor fuel filter, with a 5/16 outlet and a 3/8 inlet. This will adapt the suction line on the bottom of the tank to the pump without the special rubber line the factory used. Put a second, high pressure filter between the pressure line and the fuel ring on the engine. I use a filter from a 80s Nissan Maxima. It's designed for FI, and it filters out the fine dirt before it gets to the injectors.

The wiring can be run from the original location, following the harness forward until it's under the tank. You only need to run the power lead, you can tap the ground point next to the fuse block to ground the pump.

Hi
I recently replaced the intunnel plastic line with 3/8" steel brake line. A 3/8" x 60" steel
brake line will cost you about $5 and works great. On the end of the steel line I use the
approprate size rubber fuel line, this seems to feed my v/8 fine.

I agree with the copper line advice. BAD! My real question is "why change the lines at all"? I've never heard of ANY failure of the lines within the tunnel that wasn't caused by an external stimulus, like a screw run through it ............. The Cap'n

QUOTE (Cap'n Krusty @ Jan 24 2005, 10:10 AM)

I agree with the copper line advice. BAD! My real question is "why change the lines at all"? I've never heard of ANY failure of the lines within the tunnel that wasn't caused by an external stimulus, like a screw run through it ............. The Cap'n

Arlington Texas fire department report. March 1992.

"Cause of engine fire determined to be failure of the plastic fuel lines. "

That was my wife's car. The report goes on to detail the failure due to cracking of the plastic.

clay, in your wifes car, was the fuel pump relocated to the front before the fire (did the line fail due to pressure or from becoming brittle from age)?

As for copper work hardening, yes, it does, but if you secure it well and use flexible couplings at both ends, there is little to no chance it will ever flex enough to create that problem. Interesting that gas reacts that way to the copper tubing, never heard that before.

It's pretty much been covered here, but I would recommend 5/16" turing over the 3/8" tubing. The 3/8" is just harder to bend, harder to route, and has larger fittings (if you are using any fittings). The 5/16" is plenty large for the fuel volume (unless may be you have a big six or V8). It also makes connecting to the 7mm fuel line and fuel pump ports easier.

Demick

QUOTE (type11969 @ Jan 24 2005, 10:33 AM)

clay, in your wifes car, was the fuel pump relocated to the front before the fire (did the line fail due to pressure or from becoming brittle from age)? As for copper work hardening, yes, it does, but if you secure it well and use flexible couplings at both ends, there is little to no chance it will ever flex enough to create that problem. Interesting that gas reacts that way to the copper tubing, never heard that before.

Yes, the fuel pump was relocated before the fire. But the 75-76 914 used the same lines, and they had the fuel pump up front from the factory. At the time of the failure, the car had carbs and a facet 8 psi pump. I had removed the FI temporarily due to the inablity to find a critical part. The part showed up 2 days after the fire.

The fire was traced back to the bend in the plastic line where it comes out of the firewall. It split and gasoline sprayed back over the hot heat exchangers at 70 mph. It lit off the magnesium in the fan shroud. The Arlington FD took a tanker truck full of water and 2 huge CO2 fire extinguishers to get the magnesium cooled down enough not to relight.

For what it's worth. I will never own another 914 with the factory fuel lines still in it. I have been literally burned once by this. It won't happen again.

well i will say the stock lines can hold some pressre when my return to the tank was clogged, my fuel pressure would climb to about 90 psi. and then when fixing it i put in my fuel reg backwards, it was running at 90 psi for 10 mins till i figured out why it was running like shit, a little rich .

1. I’m redoing mine for a Megasquirt install and using 5/16" stainless from Summit for both feed and return lines. The MSD pump I’m using has a 3/8" inlet and a 5/16" outlet, so it’ll serve to reduce the diameter from the tank outlet to the new feed line.

2. I’m following Clay’s lead and using 2 filters also, one before and one after the pump.

3. I ran a single power wire from the rear trunk where I’m mounting the MS relay box to under the tank, and plan to ground it in there somewhere.

Anyone have any pics of the fuel filter located under the tank?

How do you access this fuel filter?

QUOTE (watsonrx13 @ Jan 24 2005, 03:49 PM)

How do you access this fuel filter?

That's exactly what I was thinking about when I asked about the filter. I always cringe whenever I hear about new cars that have a fuel pump problem because you have to pull the fuel tank to deal with it. I recognize why it's necessary to have one up front between the tank and the pump, but I'd hate to have to pull the tank to deal with a filter problem.

The later models have an access panel below the tank in the trunk that the pump mounts to.

pic

filter behind the pump

Here's my pump and filter moved to the front trunk.

Demick

Damn.

ejm, I wish I would have seen your pics about 15 years ago when I relocated my pump up front. I bought the late pump and cover, but "invented" the rest. I never saw a 75 or 76 before I did my car.

I Didn't know the firewall was "flanged" and I didn't know that the fuel pump mount plate unbolted from the pump like that. Looks like I should redo that on my car....

Did I thank you for the pic?

I just happened to finish this task over the weekend. It's not as clean as the other posts but it'll be covered by the gravel gaurd.

Cheers,
Nate

even though it's covered by the gravel guard, i would NOT run my fuel pump/filter there.

in an accident or incident (hit a curb, etc), it would be much more likely to have a problem with things located there rather than up directly below the fuel tank or in the front trunk.

my 02, n

QUOTE (ClayPerrine @ Jan 24 2005, 05:09 AM)

As for the fuel filter, put one in front of the pump under the tank. You can use a carburetor fuel filter, with a 5/16 outlet and a 3/8 inlet. This will adapt the suction line on the bottom of the tank to the pump without the special rubber line the factory used.  Put a second, high pressure filter between the pressure line and the fuel ring on the engine. I use a filter from a 80s Nissan Maxima. It's designed for FI, and it filters out the fine dirt before it gets to the injectors.

I would put as fine a filter as possible BEFORE the fuel pump.

The stock Bosch roller pumps have very close tolerances, and anything that will foul the injectors will probably also be harmful to the pump. That's why the factory put them before the pump. The cumulative effect of grinding many little bits of grit under the rollers in the pump will cause it to lose capacity. That makes it have to work extra hard to hold enough pressure in the line for your fuel injection to work well. Eventually it will wear out, and they ain't cheap to replace when they do.

Use a filter (like the factory big box one) that has enough size so it isn't restrictive. Those pumps suck hard; I would be surprised if they don't suck the guts right out of a carburetor filter. Even if they don't, they are moving so much fuel that you may be changing the filter more often than you want to. Most of what they pump is returned to the tank, but they have to move enough to keep the pressure up at the injectors.

QUOTE (Natedog @ Jan 24 2005, 10:47 PM)

I just happened to finish this task over the weekend. It's not as clean as the other posts but it'll be covered by the gravel gaurd. Cheers, Nate

Nice sharp edges to cut those rubber lines.......

Yes, I am being a bastard on this subject. But if I prevent even one 914 owner from watching his car burn on the side of the road, then its worth it.

Well - those are good points, and I don't want to have a fire on my hands! So I'll take another look at the pump/filter and try moving it up into the trunk like Demick did.

Cheers,
Nate

I took your suggestions to ACTION!
I moved the fuel pump into the front trunk area.
This 914 has been in TWO fires before I got it. I don't want to have # 3 happen on my watch!

Cheers
Nate

here is mine.... doesnt get much slicker than 2 brass 90's

facet on rubber isolaters....

NateDog, I didn't see any problem with that location .... 911's have had it there from at lease ~1969 to '89. I would bet money that VW/Prosche relocated the 914 pump under the tank because they had the room, but it wasn't bad to place it next to the steering rack. My car and another GT replica I work on both have the pump located there. Personally, i would worry more about placing an object in my front trunk that would slide over and hit the pump.

As for comment about the pump being mounted below the steering rack and an accident causing trouble there, if you hit that hard, your not worrying about the pump or the lines, because if you bend that support member, i have a feeling that the pump is the least of your worries... ie: welcome to frame alignment and body shop land.

Otherwise, nice/clean job on your install.

Friends:

Mine:

bout timne you wandered over here BigD

BigD - thanks for the comments.

I like this new spot for the pump better than underneath. It'll be easier to work on and change out the filter.

Cheers,
Nate

nate, you are going to hate that pump solid mounted to the body

Aaron - I see that you used some small rubber bushings to mount the pump. I used a couple pieces of rubber that add up to about 1/3 of an inch. It might not be enough to make a difference, but it's what I had on hand. I'm gonna give it a try first, but I'll keep an eye out for some rubber bushings.
Now that I've moved the pump up to the trunk I've got a lot more space to work with. I was kinda limited for space when I had it down underneath.

Cheers
Nate

DAPO...but whatever, it works....

-L

Here's mine. I relocated the pump in my 74' using a cover plate from a 75-76' I extended the wiring through the center tunnel. I used threaded rivets in the firewall.

Only problem is that with the old stye pump, you have a lot of hoses stuffed in there. I wish I had a new type pump with a single inlet and outlet. Less hose to worry about.

- Bryan

The 75 and 76 cars had fuel pumps with 1 inlet and 1 outlet.

Yup, I'd buy a pump from a 75-76' if I hadn't already sold one of my kidneys to buy a new early style pump about a year before I did the relocation.