Electric Fuel Pump

I recently installed one of CB Performances' 3.5 lb electric fuel pump. Twice now the thing stopped running and I didn't know it until the engine quit due to fuel starvation. It comes back on after a few minutes. Is there a thermal switch in the thing or do I have other electrical problems. I thought I would get any comments before I dive into it. What I thought I would do first is carry a tester and see if when it quits, do I have potential at the fuse block? Any other suggestions?

I've got (the rotary) one and have no problem unless I forget my "secret" power switch is on "OFF".

Warren:

Checking at the fuse is what I thought. Even better would be to check right at the pump, if you could turn the wheel out of the way or something to get at it.

There is no thermal switch as far as I know in a CB rotary pump - it keeps turning no matter what (except in your case!) How did you ground the pump where you mounted it?

Is the reason you put in a new pump that the old one was quitting? If so, then the problem sounds upstream from the pump in the wiring somewhere.

This may be basic but maybe the filter is getting clogged then when the motor shuts down the filter back flows some, allowing for a restart. ~ Alan

I was thinking clogged filter or no air vent to fuel tank so it creates a vacuum. Do you either have a small air vent line or a vented cap? If not try loosening the cap - which would let air in tank. You need a good clean tight ground too. It should pump and pressurize line to 3.5# then stop and restart when pressure drops. On on my old MGC, I used to have to be whacked pump by rear wheel every once and awile -- was again good for few months then (just to appease LUCAS the Prince of Darkness).

Hi Warren.. I've always heard that these type pumps should be located near the gas tank because they push fuel and not pull it. that being said you might consider relocating it near your tank and closer to battery w/good ground. of course I may be way off here too.. LOL.. good luck my freind!

Speedster "D"

Alan - I don't think it's the filter as when I pulled over to the side of the road, I could't hear the pump running.
Gordon - I installed the rotary pump because I wanted to "clean-up" the engine compartment. I actually fixed something that wasn't broke.
David - I installed the pump right under the fuel tank. And, although I think the ground is good, I will check it. How do you like that, an answer before you responded.
Wolfgang - I am not sure this pump shuts down when 3.5 lbs is reached. The other day when I had the key on to work on other issues, the pump just kept running. Running, of course, until I smelled gas and pulled the wire off the fuse block. Bad on me. Lots of wasted fuel on the garage floor. It only came out of one of the big Webers. Now that I think about it, maybe that is why the pump didn't see any backpressure. That would explain why it didn't shut off in the garage, but why would it shut off while driving? I just love wrenching on these things. What else would I be doing? Oh, maybe driving the damn thing would be a possibility.

Warren,
Knowing the way you drive you're just going faster than the fuel...;)

Seriously,
if you "pulled the wire off the fuse block", you might have damaged the connection. I'd check there first.

Warren
Call CB and tell'em how it is. They'll be there for ya.
Ernie

Check your ground wire

One concern with an electric fuel pump is that should you have an accident and a fuel line is ruptured the pump will continue running this could easily cause a fire and we have seen what happens to a speedy when it burns! My car has fuel injection so the fuel pressure is way up there, my aftermarket engine management system has an output to turn the fuel pump on and off. It also shuts the fuel pump down as soon as the engine rpm drops to zero. How you sort his out on a car without a programable management system is going to be difficult. Any body got any ideas?

Easy:

Add another oil pressure switch to the engine and wire a relay to it such that when oil pressure drops to zero the fuel pump is switched off. Some oil senders have two connections: 1 for a gauge and another for a light. You may use the light connection to drive the relay.

Same trick is used on Hydroxy generators to positively stop them when the engine is stopped.

gn

You can also use a relay from a VW Rabbit or Audi Fox. It allows you to connect to the tach wire and keep all the wiring up front. The relay has its own fuse for the fuel pump. I think you can search for more information about this option.

I am in the middle of rebuilding my 44 IDFs, thanks to Lane. When I went down to my local buggy shop to buy a kit, they told me that 3.5 lbs of fuel my rotary pump was producing was too much. They insisted I needed a pressure regulator. They said the needle valves on the floats may not stop the flow. I called CB Performance and they said 3.5 lbs was fine. Also, they said the pump doesn't shut off when it sees back pressure. By the way, my float was way off, which was probably why I was pumping fuel on the garage floor. Any thoughts on the pressure regulator? I guess it wouldn't hurt.

Warren,
I have the same carbs and fuel pump and haven't had any issues yet. I don't know the specifics of the install other than we decided to install it right behind the "passenger area" wall. My wrench didn't seem overly concerned with it being too far away from the tank.
Also, I can hear my pump running if I turn the key but only when the car has been sitting for awhile. I don't hear it if I shut the engine off, run into the store, come out and turn it back on. I know my buddy installed two relays, one for the fuel pump and one for the oil cooler fan. I can ask him what he did specificly if you want.

Warren....
13,000 miles on my 44 IDFs with the rotary pump mounted below the tank: FLAWLESS!

Warren:

The fuel on the garage floor (??) is a little disturbing;

If you had a stuck (open) float valve, then the gas would flow through the bowl overflowing it, then down the inside of the carb and into one or more cylinders. It should stay in there, unless it finds its' way out through an exhaust port, but I doubt it. This also holds true for a mis-adjusted float level, although THAT wouldn't necessarily make the bowl overflow - it could heat up when first shut off, percolate the gas out and maybe THAT would end up on the floor, but it's a long shot and would take close scrutiny to find out what's going on.

If it's on your floor, then something else is going on and it's probably leaking from another place.

On the pump; I would also check to see where the fuel lines run close to the engine. If they are right above a heat source (this includes the pump being close to heat, too) then the fuel lines are subject to vapor lock as the heat percolates the gas in the hose. I read above that you mounted the pump right under the tank, so that'll eliminate vapor lock ahead of the pump (they can't create enough suction to overcome it).

The CB rotary pump should be running as long as the key is turned on. Period. It has no pressure switch in it to turn it on and off - it just runs. If it's NOT running, then you've either got a bad pump, or it's not getting 12 volts or has a bad ground. If it IS running and the engine isn't because it's not getting gas, either you have a line blockage or vapor lock.

From what you've described in posts above, I'm still thinking of an intermittent electrical connection on the pump.

That pump puts out 3.5 lbs. of pressure, or just about as much as a stock, mechanical, VW pump. Adding a pressure regulator in line with that pump is a waste of money. The pilot valves at the floats should be able to handle it just fine (mine have been doing so for 8 years....)

gn

After what Gordon said maybe it's not my fuel pump I hear running? I hear something running though. What else might it be?
Which brings me to another issue (not to hijack). A funny thing has been happening with my headlights. When I turn them on they don't come on right away. What happens is very strange; the highbeam light on my dual guage lights up and after a minute or two the highbeam light goes out and the headlights come on. The parking lights come on right away, it's only the headlights that take a few minutes.
If it's best, I'll move this to another thread, I just thought I'd throw it out there.

"Ghost in the Machine", Mickey.

OOOoooooooooooooo........

Seriously, though, that's just weird. Maybe heat-related? I'd look for loose connections or partially broken wires.

Loose connection, or, maybe a going-bad headlight switch.

Or maybe it's one of those safety features from the 1970's: Let you sit there for a minute or two in the dark to contemplate whether or not you really are too drunk to drive......

Oh, you're OK? Well, then....You've been a patient dude. Here's your headlights.

Seriously, your parking lights are on a separate circuit within the headlight switch, and they seem OK, so I would concentrate on the headlight side.

The intermittent high-beam light is intriguing, though. THAT is tied to the high beam circuit, so now I'm betting on a loose ground somewhere, because when the headlights are OUT (but the switch is on) they're finding ground through the high beam lamp (believe it or not) and causing it to light. When they find their proper ground (it's intermittent, remember?) then they get a better ground path through THAT and the high beam light goes out.

Make sense? (I know I'm confused....)

gn

Thank you Gentelman. It indeed was a bad ground. I searched high and low for hours and finally found it. Not really, I just popped the hood and there it was, just a bad connection on the ground. It took all of 3 minutes to fix.

Now back to your regularly scheduled Electric Fuel Pump thread -

Carbs:
Yesterday I finished up the 44 IDF rebuild, put them back on the car and it ran like a dream. (By the way, does anyone know what IDF stands for?) I checked the flow and all four barrels and they were almost exactly the same. I will recheck after I adjust the valves and check the timing, but it runs so smooth and quick I hate to mess with anything.
Fuel pump:
As far as the fuel pump goes, luckily it didn't work when I turned the key on. That made troubleshooting pretty easy. I checked the ground by cleaning it up and re-attaching. Still no potential. I checked the fuse block with a tester and when I pushed on the tab, the pump came on. It turned out to be loose tabs holding the fuse. I bent them a little, and reinstalled the fuse. Seems to work fine.
Fuel leak:
It doesn't leak now with the engine off and the fuel pump on. I can only think that perhaps the fuel was coming out of a loosely tightened hose clamp. Not sure, but after rebuilding the carbs, I can't see how the fuel could have been pumped out of the carb. I will be returning the pressure regulator. I don't think I need it, regardless of what my local shop says.

Anyway thanks to Gordon, Danny, Lane and all who offered suggestions. Man, you guys are a great source of information. Wish we could all get together and go for the biggest caravan cruise in the world. The problem with that is there probably isn't a Pub large enough to hold us all. Well that settles that, let's head for Lane's house.

Hey Warren, I've often thought that "IDF" stands for "I Didn't Fix it". I've had good luck this weekend, as have you, so maybe I'm wrong. Hey, it could happen.

C'mon over. I've got beer in the fridge.

Went on a 200 miles round trip cruise from Morro Bay to Carmel and back with Eddie Janis (black, flawless Speedster), 2 Cobras, 1 Ford 500 GT, 3 muscle Shelbys, and a couple of other fun cars. The 44's never missed a beat, nor did the electric fuel pump. I did use quite a bit more fuel than Eddie though. He's running 44's on a really nicely built 1776. I am running 44's on a 2180 (I think-never verified it yet. Haven't had the heads off for any reason). Could that be the difference? My main jets are 135s, (just what the Weber folks say they ought to be). However, that is not what Tomlison book says, he says they ought to be around 165. Well, wouldn't that even use more fuel? I really don't want to mess with the jetting as it is running really good.

Warren;

Sounds like your fuel delivery problem is solved!

"I really don't want to mess with the jetting as it is running really good.

1776cc engines were GREAT for gas mileage, often up into the 30's, no problem. 2100+ engines and larger are often at least 10 mpg less than a 1776. I've got a 2,110 running slightly rich and I do 26 - 29, depending on speed and I think that's great.

If you're anywhere in that range, and if it ain't broke, don't fix it...

gn

Warren,
I had a 1600cc with 34's in it before I put in my CB 2005cc engine with 44's and I've noticed my gas gauge doesn't work the same as it used to and the world seems to drive much slower all of a sudden. ;-)

Warren -

The car looks great (old school)! Sounds like a great way to spend the day! Glad to hear you're having fun with your Speedy again!

Thanks Jim. Yes, it's truly been a lot of fun. I am still sorting out a bunch of minor problems, but I will get it right eventually. I absolutey don't know how the guys with minimal wrench experience can even get along with these cars.

Gordon - I went to my local VW service guy to get some parts to fix an oil leak problem - too much oil blowing out the back. Yes, I've read the breather thread, but I am going to do what this guy suggests for now. That is to install lines from the breather box to the air cleaners. I will do that and see what happens.

The interesting point was when we talked about the fuel pump again, he insisted that Weber 44s require NMT 2.5 lbs. He stated the float chamber valve seats are just not strong enough to hold the extra pressure back. He claimed that his Weber manual states that 2.5 is the max. When I told him that a bunch of my buddies said that 3.5 lbs was fine, he got a little testy, talking about his 40 years of experience and you know, blah, blah, blah. I guess I will wait and see. I don't want to piss this guy off as he has been pretty good to work with, i.e., he said to bring in my main jets and he will measure them for free to see if they really are what is stamped on them. I think I am running too rich, but then, what the hell do I know. Like you said, "if it ain't broke, don't fix it.

Yup, install breather hoses from the breather box to the air cleaners. Should help, and can't hurt. Make them around 5/8" ID, if you can.

The interesting point was when we talked about the fuel pump again, he insisted that Weber 44s require NMT 2.5 lbs. He stated the float chamber valve seats are just not strong enough to hold the extra pressure back. He claimed that his Weber manual states that 2.5 is the max. When I told him that a bunch of my buddies said that 3.5 lbs was fine, he got a little testy, talking about his 40 years of experience and you know, blah, blah, blah. I guess I will wait and see. I don't want to piss this guy off as he has been pretty good to work with, i.e., he said to bring in my main jets and he will measure them for free to see if they really are what is stamped on them. I think I am running too rich, but then, what the hell do I know. Like you said, "if it ain't broke, don't fix it.

I'm not a Weber expert. Let's see what those on here folks say, but there are a LOT of people on here running the same carbs with CB rotary pumps putting out 3.5 lbs. or so with no problems. All I had was Bob Thomlinson's book on Webers and I've lost it so we'll need some help.

Getting back to your carbs; So how do you know you're "running too rich"? Spark Plugs sooty? Black smoke or backfiring out the exhaust? Gas mileage less than 20 mpg? Have you put an air-fuel mix gauge on it to see just what it is?

You said up above that it's running great, but now you want to mess with the fuel mixture? OK, pull the main and idle jets and see what sizes they are (BTW - 135 mains on a 2180 would be silly lean), and at the same time take along your spark plugs and see if your guy can tell if it's running lean or rich from the plug colors (hint - there's a plug color chart in most Chilton Service manuals - find them in your local library. Second hint: label each plug for location, as you don't know if it's different on different cylinders yet, so location is important). Better yet, see if he has a wide band air fuel mixture gauge and have him test your car. THAT should settle things for sure.

good luck.....gn

3-3.5 lbs. is what EVERYONE says, including Bob Tomlinson and I think Jake. At least that's what mine is set at.