relocating fuel pump, what do I need? |
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relocating fuel pump, what do I need? |
lolkema |
May 9 2023, 01:21 PM
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#1
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Newbie Group: Members Posts: 24 Joined: 17-July 05 From: Idaho, USA Member No.: 4,425 Region Association: None |
I always try to use the search options but each time I get about 5 million hits and I never seem to be able to find the answer I am looking for. So apologies if this has been asked before, now onto the question:
I would like to relocate the fuel pump to the front to prevent vapor lock issues. Can I use the original fuel pump or do I have to get a newer model pump? This is on a '74 fuel injected 1.8. I did already replace the fuel lines with stainless steel pipes and replaced all hoses last year. Thanks for the help! |
r_towle |
May 9 2023, 01:32 PM
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#2
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
well, you need to do a few things, depending upon your preference.
the stock front mounted pump is under the tank and has an access panel on the drivers side bottom of the "firewall" that is between the tank and the front trunk. One option is to mount it in the stock location, which requires cutting that rectangle in the wall, and finding the OEM stock pump mount (they are out there) A second option is to mount the pump down below the tank, next to the steering rack, yet covered by the skid plate...which is a common choice. Either option requires the newer style pump which is one in, and one out. Its not too costly...it was used on many vehicles so its readily available for well under 100 bucks. hose routing in the front is tank--screened fitting---pump--filter---passenger side fuel rail---drivers side fuel rail...back to tank There is a fuel pressure regulator in the loop also. Rich |
Dave_Darling |
May 9 2023, 05:07 PM
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#3
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914 Idiot Group: Members Posts: 14,986 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
I disagree with Rich about what pump you need. My 74 1.8 had the stock three-port pump up in the steering rack area.
Extra stuff you will need that isn't on your car: - A wire for the fuel pump power supply. - Fuel line converter fittings. (There are pre-made hoses with 7mm ID on one end and 9mm ID on the other, or you can mill or weld up fittings on your own, or use brass plumbing fittings from your hardware store.) - New fuel hose. (The hoses on your car are not new.) It's a good idea to change the center tunnel fuel lines to Tangerine Racing's stainless lines, because the supply line will now have a lot more pressure in it than it originally did. You will have to do a bit of re-plumbing of the return hoses. In particular, you will have to move the Y fitting that connects the fuel pump's "R" port into the return line from the rear up to the front of the car. Since the return line is a larger diameter than the regular fuel hose, you have to do some adapting, either with fittings or with a special piece of hose. You will need to run your fuel pump power wire from the stock plug under the engine bay, through the main wiring harness, up into wherever you are putting the pump. It is possible to power it from a regular "switched power" source, but I strongly recommend you keep the original functionality of the fuel pump control system. Which means running the power wire up front. --DD |
r_towle |
May 9 2023, 05:36 PM
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#4
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
Sadly you asked this question after I put everything back.
But I assume the fuel pump power is run off the fuse box? I can’t see my 75 because it’s all under the tank again. If you can find a new 3 port fuel pump, congrats. The two port pumps are readily available and slightly easier to plumb. Rich |
Dave_Darling |
May 10 2023, 01:41 AM
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#5
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914 Idiot Group: Members Posts: 14,986 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
The L-Jet fuel pump is run from the dual relay. It runs when the vane inside the air flow meter is opened, and possibly also when the starter is cranking.
You can run it from a "switched power" source on the fuse panel, but that can lead to continuing to pump fuel after the engine stalls. Or, say, if there is a wreck or an engine problem. That's a fire danger, and you're better served by keeping the stock functionality. --DD |
ClayPerrine |
May 10 2023, 07:36 AM
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#6
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Life's been good to me so far..... Group: Admin Posts: 15,463 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
The L-Jet fuel pump is run from the dual relay. It runs when the vane inside the air flow meter is opened, and possibly also when the starter is cranking. You can run it from a "switched power" source on the fuse panel, but that can lead to continuing to pump fuel after the engine stalls. Or, say, if there is a wreck or an engine problem. That's a fire danger, and you're better served by keeping the stock functionality. --DD (IMG:style_emoticons/default/agree.gif) The wire to the fuel pump can be rerouted to go forward with the wiring harness. You will have to extend it, following the factory harness, all the way up under the tank. I also like to put in a hidden switch in the fuel pump wire as a pump cutoff. The pump ground can be connected to the ground point by the fuse box. You can use a stock 3-port pump. But I won't go looking for one if you don't have one. They are outrageously expensive these days, and they make the plumbing more complicated. I use an Airtex E-8445 pump and a fuel filter for a carbureted 70s Ford as a filter screen. The fuel filter is threaded on one end, and the inlet side is the same size as the suction port on the tank, so you don't need any adapter hoses. I have been using the Airtex pump for years, and had no issues with it. I even use it on the 4.0L monster motor. But I still carry a spare in my took kit. But I also carry enough hose and some wires and alligator clips so that I can siphon gas from the 914 and put it in the tow vehicle if we are somewhere where we don't have enough gas to make it to a gas station. |
lolkema |
May 10 2023, 08:41 AM
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#7
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Newbie Group: Members Posts: 24 Joined: 17-July 05 From: Idaho, USA Member No.: 4,425 Region Association: None |
Thank you all for the info, I do have the 3 port fuel pump, everything in the car is stock. I am happy I can use the original fuel pump, now it will be just some pieces of hoses, clamps and wiring that I need. I have already replaced the fuel lines with the stainless steel pipes so that has been taken care of.
Thanks! (IMG:style_emoticons/default/beerchug.gif) |
burton73 |
May 11 2023, 09:31 AM
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#8
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burton73 Group: Members Posts: 3,524 Joined: 2-January 07 From: Los Angeles Member No.: 7,414 Region Association: Southern California |
Sadly you asked this question after I put everything back. But I assume the fuel pump power is run off the fuse box? I can’t see my 75 because it’s all under the tank again. If you can find a new 3 port fuel pump, congrats. The two port pumps are readily available and slightly easier to plumb. Rich 3 port brand new Bosch made in Germany are available but cost a lot. I had one in number 41 my 6 that I switched out for Fuel Injection Bob B |
dr914@autoatlanta.com |
May 11 2023, 10:56 AM
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#9
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914 Guru Group: Members Posts: 7,857 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
fuel pump relocatation kit or fuel pump update kit, you can call me for advice and can buy either from our site
I always try to use the search options but each time I get about 5 million hits and I never seem to be able to find the answer I am looking for. So apologies if this has been asked before, now onto the question: I would like to relocate the fuel pump to the front to prevent vapor lock issues. Can I use the original fuel pump or do I have to get a newer model pump? This is on a '74 fuel injected 1.8. I did already replace the fuel lines with stainless steel pipes and replaced all hoses last year. Thanks for the help! |
JamesM |
May 11 2023, 01:56 PM
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#10
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Senior Member Group: Members Posts: 1,900 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
I always try to use the search options but each time I get about 5 million hits and I never seem to be able to find the answer I am looking for. So apologies if this has been asked before, now onto the question: I would like to relocate the fuel pump to the front to prevent vapor lock issues. Can I use the original fuel pump or do I have to get a newer model pump? This is on a '74 fuel injected 1.8. I did already replace the fuel lines with stainless steel pipes and replaced all hoses last year. Thanks for the help! First thing you need to do is decide which way you want to go as their are various routes you can take. If you want to go with how Porsche did it there are two ways, but people have come up with many more of their own as well. Factory bulletin on relocating the pump on early cars involves moving the 3 port pump by the steering rack (though you can move a 2 port pump here as well) The other way the factory did it was on 75-76 cars to mount it on a separate removable "bubble" panel in the front trunk under the driver side of the tank. This uses the 2 port pump, smaller tunnel feed lines, some 75-76 specific mounting parts and a hole being cut in the bulkhead in front of the gas tank. I prefer the late style install if you have the parts to do it. I always run the smaller feed line in the tunnel for the sake of easier hose routing/no inline reducers needed at both ends and in either case (trunk or steering rack) I like to run the 2 port pump as well, again as it simplifies the hose setup. Quickest/cheapest way from a parts sourcing standpoint though is probably going to be putting the 3 port pump by the steering rack. |
914_teener |
May 11 2023, 09:24 PM
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#11
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914 Guru Group: Members Posts: 5,197 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
I always try to use the search options but each time I get about 5 million hits and I never seem to be able to find the answer I am looking for. So apologies if this has been asked before, now onto the question: I would like to relocate the fuel pump to the front to prevent vapor lock issues. Can I use the original fuel pump or do I have to get a newer model pump? This is on a '74 fuel injected 1.8. I did already replace the fuel lines with stainless steel pipes and replaced all hoses last year. Thanks for the help! First thing you need to do is decide which way you want to go as their are various routes you can take. If you want to go with how Porsche did it there are two ways, but people have come up with many more of their own as well. Factory bulletin on relocating the pump on early cars involves moving the 3 port pump by the steering rack (though you can move a 2 port pump here as well) The other way the factory did it was on 75-76 cars to mount it on a separate removable "bubble" panel in the front trunk under the driver side of the tank. This uses the 2 port pump, smaller tunnel feed lines, some 75-76 specific mounting parts and a hole being cut in the bulkhead in front of the gas tank. I prefer the late style install if you have the parts to do it. I always run the smaller feed line in the tunnel for the sake of easier hose routing/no inline reducers needed at both ends and in either case (trunk or steering rack) I like to run the 2 port pump as well, again as it simplifies the hose setup. Quickest/cheapest way from a parts sourcing standpoint though is probably going to be putting the 3 port pump by the steering rack. Or put it behind the passenger side on the "firewall". Two rivnuts the stock isolators and a fuel filter. All servicable from that location without pulling the cover and entagling extra fuel lines underneath the steering rack cover. Done both and for sure the relocation in the rear just above the air deflector in my opinion is WAY easier. |
lolkema |
May 13 2023, 08:49 AM
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#12
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Newbie Group: Members Posts: 24 Joined: 17-July 05 From: Idaho, USA Member No.: 4,425 Region Association: None |
Or put it behind the passenger side on the "firewall". Two rivnuts the stock isolators and a fuel filter. All servicable from that location without pulling the cover and entagling extra fuel lines underneath the steering rack cover. Done both and for sure the relocation in the rear just above the air deflector in my opinion is WAY easier. But would that cure the vapor lock issues? It seems to me it is still located in a spot where it gets really hot. |
rhodyguy |
May 13 2023, 09:01 AM
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#13
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,080 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
When mounting the pump on the FW under the tin, the pump is far away from the vent on the flapper valve that heats up the pump in the stock location. That’s where I mounted my LP pump. I removed the stock pump wire end for one that fit the new pump and utilized the stock pump wires. Andy’s jumper wire trick to power the pump.
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StarBear |
May 13 2023, 09:20 AM
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#14
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Senior Member Group: Members Posts: 1,884 Joined: 2-September 09 From: NJ Member No.: 10,753 Region Association: North East States |
Also with a 74 1.8: used the stock 3-port pump but switched to the circular filter instead of the square one. Once in a while it rattles around in there but then goes away.
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