TR6 Fuel pump question

[Peter R]

Hello all, I just introduced myself on the new member forum, and I have a question.
The fuel pump of my TR6 (USA carb version) has developped a small external leak, and I consinder replacement with a Facet electrical pump and pressure regulator.
I fear that if these mechanical pumps fail, and start leaking fuel into the engine oil system, this may go unnoticed untill disaster strikes.
I also think that the likelihood of this kind of failure becomes more real as result of the ethanol content in today's fuel.

So here my questions: Is my fear justified ? and what is your experience with the Facet electical pumps ?
Thank you,
Peter.

 

[Geo Hahn]

I realize a TR6 pump differs somewhat from a TR3 or 4 -- but on those the only leaks I have had thru the years have been very slight and totally my own fault: insufficient tightening of a fuel line fitting and over-tightening of the bail holding the glass bowl (distorted the casting).

I think the seal commonly supplied these days for the bowl is ethanol-safe but if in doubt, an effective seal can be made from cork. I have used both at times.

The pressure involved is so low (compared to PI systems) and the leaks, if any, so small that the risk is possibly no greater than any of the other fuel connections (which will still be present with an electric pump).

Of course, there are other reasons why some will prefer an electric pump and indeed I carry one as a spare to get me home if/when the mechanical fails on the road.

Oh, and welcome to the Forum!

 

[TR3driver]

Hello Peter, and welcome to the asylum!

If your mechanical pump still has the original diaphragm in it, then it makes sense to me to replace it as preventative maintenance. They last a long time, but not forever and 40 years is a very long time by automotive standards. Any diaphragm (or pump) made in the past 20 years or so should be ethanol-resistant. Here in CA, we had MTBE even before ethanol, with effects on rubber very similar to that of ethanol. But with that simple precaution, like Geo, I've never had other than minor external leaks over several hundred thousand miles.

Electric pumps are not without their own hazards as well. For example, I accidentally left the ignition on in one of the Stags (which came with electric pumps originally, which also fail from ethanol/MTBE) and a tiny leak in one of the float valves let it fill a cylinder with fuel until the engine would not turn over. There were also some pressure regulators that were not ethanol-resistant and would start leaking fuel. (After all, they have a diaphragm inside similar to the mechanical pump.)

BTW, the Facet pumps are available in various pressure ratings. If you are going to use a regulator, be sure to get a pump with a rating that is several psi higher, as the regulator needs some pressure drop for proper operation. But for normal street operation, you can just get a pump with the proper pressure rating for your carbs and skip the regulator.

 

[Peter R]

Ok, thanks for your reply, it makes sense to carry an electric pump as spare, I ordered a rebuild kit for my mechanical pump, this pump may be as old as the car itself, and a rebuild is probably long overdue.

 

[Lukens]

I carry one as a spare to get me home if/when the mechanical fails on the road.

Oh, and welcome to the Forum!

George,
I've considered doing he same. Do you carry the fittings, wiring, etc. to make the swap in an emergency? Would that be any easier than rebuilding your mechanical pump (in an emergency)?
Russ

 

[TR3driver]

The wiring can be as simple as a couple of "clip leads", which are good things to carry anyway. I keep 3 or 4 of them tucked in with the DMM, as they are also handy for testing or if a wire or switch fails. Or on a TR3, even if you lose the ignition key

https://www.amazon.com/SE-TL10-10-P...ref=lh_ni_t?ie=UTF8&psc=1&smid=A2WRUBMLJPZ2AL

 

[Lukens]

https://www.amazon.com/SE-TL10-10-P...ref=lh_ni_t?ie=UTF8&psc=1&smid=A2WRUBMLJPZ2AL

I've got a few hanging around, but for 4 bucks I ordered a set. Thanks

My question to George was, is it any easier to plumb an electric pump in (on the road) then fix the mechanical one. Your opinion?

 

[Geo Hahn]

Yes, along the side of the road it is much easier to plumb the electric than to repair or swap the mechanical.

I have it ready to go with a fuel line and clips. It attaches to the 5/16" soft line that normally feeds the mechanical pump and the other end to the 1/4" hard line to the carbs.

Takes only a minute or two to hook up. I have used it more often on others' cars than on my own.

If you use the white-wire side of the coil for your power feed then the pump switches on & off with the ignition switch.

 

[TR3driver]

Well, I've never actually tried rebuilding a mechanical pump on the side of the road; but temporarily plumbing in an electric sure seems easier to me. No little screws to lose in the dirt! When I had to substitute the spare on the Stag (which already had an electric pump), it only took perhaps 15 minutes to get back on the road again.

 

[Lukens]

Yes, along the side of the road it is much easier to plumb the electric than to repair or swap the mechanical.

I have it ready to go with a fuel line and clips. It attaches to the 5/16" soft line that normally feeds the mechanical pump and the other end to the 1/4" hard line to the carbs.

Takes only a minute or two to hook up. I have used it more often on others' cars than on my own.

If you use the white-wire side of the coil for your power feed then the pump switches on & off with the ignition switch.

I like that.

 

[TR3driver]

If you use the white-wire side of the coil for your power feed then the pump switches on & off with the ignition switch.

On later TR6 without a white wire on the coil, you can grab power from the white (or green) wire at the fuse block. Which will also leave the pump controlled by the ignition switch.