MGB & GT Forum

I have a 1965 MGB with 3 main engine that needs a complete rewire job. Two questions......1. Where is the best location to mount the electric fuel pump; 2. The original harness goes under the car to the rear section, is there a better routing for this?
Nick

1. Stock location ahead of the right rear wheel

2. Not really. Some have run it along inside the car along the passenger side inner sill but I see no advantage to this.

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"Speed costs........how fast you want to spend?"

If you went to GI and wrote "mgb fuel pump location" one of the pics you'd get is below - I believe this is from Dave's pages. But you wrote "electric fuel pump" so what do you have?

IMO to run the oem rear loom inside the car will take a bit of thinking about as the wires are already cut to length and terminated. OTOH inside is where I'll run my AAW as they get cut to length and don't come with attached terminals on the end.

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Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.



Edited 1 time(s). Last edit at 2017-04-30 06:41 PM by MGB567.

I looked at the possibility of running the rear part of the loom inside, as my new floor panels didn't have captive nuts attached. Decided it was a fool's errand and ran it as original. It does make a lot of sense when you're under there, and everything fits up as it should.

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Chris Howells

1968 MGB Purchased already dis-assembled but which is largely back together so I'm a lot less ignorant.

Oops, I goofed! I have the regular, not electric fuel pump. Thanks for catching that.
Nick

Ahh...what's the "regular pump"?

All MGB's had electric pumps from the factory.

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"Speed costs........how fast you want to spend?"

I was answering Barrie Braxtons question from an earlier post.

The advantage of the earlier pump location is that any leakage of gas happens outside the car and its boot, so no dangerous formation of explosive mixtures. The disadvantage is the higher vulnerability of the open contacts in the traditional pump from the environment (the small vents and hoses on the contacthousing provide some protection though). BL later moved the rear of the pump with its contact part into the boot area, adding some risk of gas escaping. However, the original location is still the best IMO, certainly if using an SU or Hardi with full electronic contacts, invulnerable to dirt.

PS I noted a slight sweating on the banjo gasket rings on my Hardi, maybe due to new types of gasoline? But it sits well outside and hereby I have no risk of explosive situations at all

I was differentiating between points pumps (noting that SUs can be IC) and one of those aftermarket jobbies many seem to like. So if OP has an SU look no further than the pic I included.

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Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.

There is no easy internal route to the rear of the car for the wiring harness. When I worked as part of the MG RV8 development team we routed the harness internal to the cabin under the centre console. This involved the addition of steel brackets welded to the transmission tunnel and a raised centre console to cover it all. Personally I'd keep the existing wiring routings. What I would do is use modern waterproof multi way connectors to remove the bullet connector collection in the engine bay. I's also add a few spare wires for things like fog lights etc.

I'm still not sure what a "regular" pump vs an "electric" pump is.

As David mentions, I suspect moving the RV8 harness in the cabin was considered a safety item. Having a harness exposed under the car may have been considered dangerous in later years.

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"Speed costs........how fast you want to spend?"

Sorry for any confusion about the fuel pump. The fuel pump I have is like the one in the picture, not one of those square aftermarket models. I have been considering running the "rear" harness through the passenger side of the car and mounting the fuel pump in the stock location. This way I only have one wire running under the car. What are your thoughts?

It'll be unreliable. A single wire will be unsupported and will eventually vibration fracture. It'll also be floppy and potentially snag on something. Put it in a bundle with other wires to give it some protection, i.e. leave the harness under the car. It's not the way we design them now but it does work and has done for 50 years.

I think OP means "regular" is a points type, whilst "electric" means electronic.

A slight confusion on terminology, like " it runs on batteries, not electricity", meaning it doesn't run on mains.

Herb

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They are all electric on the B, some use mechanical points, and there are now electronic ones. I fitted an electronic Hardi pump last year, which still makes a similar priming sound to the points SU when you turn on the ignition, and doesn't require any vent pipes to be fitted, so the oe vent pipes I had coming from the boot were just tucked up and left in situ..