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Discussion Starter · #1 ·
My 72 has a high pressure fuel pump mounted under the car just behind the drivers seat and ahead of the rear wheel. The pump literally just died last week so I have to replace it now. I've hated this location from day one. It's my understanding that my EFI system is from a later model Manta that would have had a 1.9 as well. I bought the Bosch pump that OGTS sells and of course the connections are different than the vintage pump that's under the car now.

I would like to move the pump & filter assembly to the are in front of the engine compartment where the battery is located. I have a reservoir there as well for the windshield washer fluid...... so I think there would be plenty of room.

Any thoughts or concerns?

I don't know if the elevation would be too high, but compared to where it is now, it would only be 2 or 3 inches higher, tops.

I've never liked it where it so close to exhaust system.
 

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Über Genius
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Electric fuel pumps are designed to push fuel, not pull it.
 
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I’ve had my fuel pump mounted to the drivers side in front of the radiator for 2 years without any problems, feeding a carburetor is not the same as FI from what I hear. I think most people mount their electric pumps underneath the tank, unless you feel robust enough to install one in the tank?
 

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Can Opeler
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Care to elaborate? Pretend I'm stupid.
Fuel pumps don’t like to suck fuel out of the tank. They prefer to push the fuel that comes to them. AKA the pump needs to be mounted below the tank fuel level. In other words directly below the tank or in it.
Best place is right beside the driver’s rear wheel well.

Search “Opel GT electric fuel pump” on YouTube. I have a video that shows the location. A high pressure pump should fit there with a bit of work.
 

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Just Some Dude in Jersey
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I use the Edelbrock returnless sump fuel pump. It's mounted in the engine compartment of my GT. It only has to high pressurize the 18" of fuel line and the rail, no direct fuel return. There is a vapor return line that you install to the vapor lines at the tank. It's dead quiet. It requires that a low pressure fuel pump be installed to bring the fuel forward from the tank. I use the red Edelbrock low pressure pump for carbs to do that. It has the regulator and swirl pot/surge tank built in. You'll have to plug off the fuel rail return line. I don't know if you can keep the stock regulator attached, I removed mine.
429580
 

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Opel Key Master
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You don't have to run a stock style, I have a couple mounted back in the same area, and they are straight through pumps. They have their own mounting ears, you just need around 40-45 PSI universal pump
 

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Opeler
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I would check the specs on pumps. Many state they should be mounted below the tank and within 18” of the tank. As stated earlier in the thread, most pumps are designed to be pushers....you can burn pumps out by not using them properly, plus from my research, they’ll be much noisier, and fail quicker as the noise is related to pump strain.
 

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Discussion Starter · #9 ·
Thanks guys......... I get it now. Like I said before I just don't like the current location as the whole apparatus just seems so exposed. Maybe I'm over thinking it. Prior to the fuel pump failure, there were no issues with the fuel injection system. It's just a pump failure so I suppose I should keep it simple and keep it where it is. The guy that owned the car before me was an employee or sub contractor of Opel Gt Source so I assume there was some level of "engineering" that went into it all.
 

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Opel Rallier since 1977
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FI universally systems put the pump at or in the tank. Pulling fuel through a long hose opens the possibility of the fuel vaporizing in the line with the suction; this is OK with a carb as each carb carries a bowl full of fuel that acts as a reservoir to cover any times if/when the pump sucks vapor. There is no such 'reservoir' in an FI system beyond the high pressure pump. So your pump really needs to go by the tank, OP, which is where it is mounted in the stock '75 Manta and Ascona FI system.

40 psi is not quite adequate for the '75 Opel system. You need excess pressure to allow the regulator to work properly. (For reference, the stock '75 FI pump will put out over 100 psi when deadheaded into a closed line.) One pump that is rated for the job is an Airtex E8312. I would imagine that the Bosch unit that OGTS has sold you will work fine too.
 

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I mounted mine on the left rear frame rail behind the rear wheel.
 

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Über Genius
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Care to elaborate? Pretend I'm stupid.
I will explain it like you're stupid.

Take a straw.
Make a spit wad.
1)Now put the spit wad on the table. Try to get the spit wad into the straw.

That is the pump pulling fuel from the tank.

2) Put the spit was in the straw, Blow the spit wad across the room

That is the pump pushing the fuel.

In this experiment, you are the pump, the spit wad is the fuel.
 

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Discussion Starter · #13 ·
I will explain it like you're stupid.

Take a straw.
Make a spit wad.
1)Now put the spit wad on the table. Try to get the spit wad into the straw.

That is the pump pulling fuel from the tank.

2) Put the spit was in the straw, Blow the spit wad across the room

That is the pump pushing the fuel.

In this experiment, you are the pump, the spit wad is the fuel.
LMAO

Thank you sir for the edumacation. I was overtaken by the idea of putting it up front and how cool it would be. I still might relocate but I'll have to stay around the tank.
 

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Opeler
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I mounted mine on the left rear frame rail behind the rear wheel.
That's exactly what I was going to say. There is a nice flat spot that is out of the way behind the rear wheel.

I've been through several configurations of in line fuel pumps before finally giving up and installing a pump in the tank. I started with a Vortech high flow pump. That one really only wanted to push fuel. When the tank started getting low it started making angry noises and if you ever turned left with less than a quarter tank it would suck in an air bubble and get very loud, and may even require manual priming to make it happy again. After getting sick of this I added a second electric pump from a ford van and a small surge tank to feed the Vortech pump. This set up seem to work better until the ford pump decided to spit one of the electric terminals out and start leaking fuel. I then installed a cheap low pressure universal pump that I had laying around in place of the dead ford pump. This again seemed to work well for a while until I was doing more autocrossing and was having fuel starvation issues even with the small surge tank and two fuel pumps and two fuel filters. Being fed up at this point, I ripped out all the extra pumps, filters, and hoses and installed a single pump in the fuel tank with a single filter in the engine bay. I used a Chevy S10 Blazer fuel pump assembly which has it's own surge tank of sorts. I have had no fuel starvation issues even when cornering on full Hoosier slicks.
 
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