Hello Alan, tbanks for the insight. Yes the mech. pump was replaced with a ’ non glass bowl’ type. It certainly sounds like I need to start out by checking the fuel pressure.
Paul
Please do not buy these cheap & nasty Chinese pressure regulators, I bought one & it was leaking fuel quite heavily into the trunk (boot.) Buy either the Holley regulator or a Malpassi Filter King
You need to go back to whoever fitted that fuel pump and get them to remove it. It is not suitable for use with Weber carbs.
The original fuel pump can be easily overhauled if necessary and will deliver the correct pressure. Overhaul kits are freely available and are simple to do.
There is no need for having a fuel regulator whatsoever fitted to your car at all if you have the correct and original mechanical fuel pump fitted.
Alan.
Check your fuel level from above, too, to make sure the float height was an error. It sounds far enough off not to be the case, but I’d double-check to make sure. Brass vs plastic floats also have different height settings.
To check from above, once you get it all back together take one emulsion tube out of each. As the carbs are just relying on idle jets, you should notice no difference at idle without emulsion tube’s and their main jets). After running briefly to allow fuel level to stabilize in the carbs, shut off and look down the carb throats with a light for obvious drips - location will suggest whether any observed drips are coming from the main or the acc pumps. Remove carb tops and peer down the chamber for the emulsion tube in each carb with a light. You should be able to see the hole to the venturi on the wall of the chamber. Generally, fuel level any higher than 1mm below that hole will cause flooding - and if you noted dripping in the throats and this fuel level observation is right at the hole, you can bet your floats are too high.
There’s no output from the gauge.
Paul,
BTW - if you don’t know if your original pump was still the glass bowl type, and even if it was if it’s long gone now, you should be able to get one off of eBay. I did for about $20. The one I got needed rebuilding. I didn’t want to deal with that, so I sent it to Ken at DBE and he rebuilt it for $115, parts and labor. The next time I have the carbs off, I’ll put it on, verify the pressure, and if possible remove the regulator and simplify the system.
Steve
The problem is not all glass bowl pumps will deliver the same fuel pressure!
AC Delco made these glass bowl fuel pumps for a lot of different manufacturers and a multitude of car models all with a variety of different size engines and carburettors, and visually from the outside all these AC Delco glass bowl fuel pumps all look the same!..But they are not all the same, they deliver different pressure and have different strength internal springs.
That is why it is so important to retain the original mechanical fuel pump with its correct internal spring that is appropriate for the Lotus twincam to deliver the correct fuel pressure for the Weber carburettors.
Also do not be tempted to purchase one of the new imitation AC glassbowl pumps that are now on the market. They are Far Eastern junk and will definitely not deliver the correct fuel pressure.
Alan.
Hello everyone and thanks for your thoughts and suggestions.
As it happens, I still have the original off the car. When the garage put a new one on (this was some time ago now), I asked for the original back…
If I was to renovate / refurbish / rebuild the FP, how difficult of a job is it? Anyone actually done this here?
maybe before you go too far, its worth looking at the entire system.
What fuel lines do you have now? From tank to carbs.
is there anything else you might consider adding to make it more livable. Some add an electric pump to bring fuel up to the carbs, makes starting quick if its been parked a spell. momentary switch or other?
Some also add a pre and post filter which evens out the pulses from a mechanical or electric…
Good news that you still have the original fuel pump!..Always assuming of course that it is the original pump that Lotus fitted as original equipment and has not been previously replaced.
Yes I have fitted lots of these AC Delco pump overhaul kits over the years on a variety of cars. Not hard at all. Obviously it depends on your practical apptitude to such things but straightforward enough job.
You just replace the parts supplied in the kit.The diaphragm just hooks in place and the valves are usually staked to hold them in place in a couple of places so just need to be carefully re-punched over.
Not all pump overhaul kits contain the spindle seal rubber (top hat seal I call it) so try and get a kit that includes this seal.
15-30minute job.
Just a thought though…The all metal pump you currently have fitted is wrong and will deliver the wrong pressure and cause flooding but why was the pump changed in the first place ?
The original pump needs to go back in the car but that puts you back to where yoiu were in the first place so what was your original fault?
Bear in mind that Weber carb flooding can be caused by many things not connected at all with the fuel pump…
Alan.
Hello Alan,
All good questions.
I’m reasonably mechanically adept, but over the years I’ve either been too busy or didn’t have the correct facilities, thus I’ve had a number of garages (some good, some not so) look after the car when it needed maintenance.
I’ve owned the car since 1983, so am reasonably familiar with it’s history.
The original fuel pump had developed a fuel leak and so I’d asked a local garage to resolve it. They swapped the pump. This was several years ago.
I’m guessing (garage has changed hands since, so I can’t ask) when they swapped the pump, they reduced the float level to stop/prevent carb flooding.
@steve lyle,
“…There’s no output from the gauge.”
Of course, I had my head wrapped around fuel pumps.
Thanks
P.
Hello All,
I’ve decided that you’re all correct and that the best course of action is to referb. the fuel pump I have. I definitely prefer that route rather than adding new H/W in the form of a fuel p. regulator.
Any kit recommendations? I’m based in the US, so was wondering if there was a kit this side of the Atlantic to avoid the international shipping.
I did see that someone on a different thread referred to the ‘oil seal’. Is this a normal part of a rebuild kit?
@alanr, I also saw that you posted previously:
“Flexolite are the people you need for all AC mechanical fuel pump parts. They even sell the elusive rubber top hat seal (that doesn’t come in a repair kit).
flexolite.co.uk/categories/ … nd-filters”
Is this the same as the oil seal referred to above?
You mention “…Bear in mind that Weber carb flooding can be caused by many things”
Very true. I just (today) went out and purchased a 0-10PSI fuel pressure gauge ($17 from a local shop here in Austin), so the current fuel pump pressure along with the rebuilt FP pressure are on my list to check so that I’m working with known data.
Thanks
Paul.
Both DBE and RD Enterprises have rebuild kits, no doubt.
Thanks Steve,
I looked at the kit from “RDEnt” and also the one from Flexolite. They were about the same cost but the Flexolite one seemed to have an extra gasket, so I ordered from there and just decided not to worry about the international shipping (which was a bit pricey)
Yes Flexolite do the full kit which I have used previously. Best to ensure that you have also ordered the ‘top hat’ spindle seal as well. I don’t think it comes in the kit.
Alan
Well Flexolite were pretty quick on the ball and have already shipped the kit. I guess when I open up the fuel pump, if the seal is damaged, I’ll have to obtain one then.
Hello @h20amelan,
Good point. I don’t think I want an electric pump but I probably could use a fuel filter.
The fuel line from the pump to the carbs is only a couple of years old. Not sure about the one from the tank to the pump.
Cheers
Paul.
I had thought you had posted elsewhere, with a photo of some older plastic line.