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Sat May 12, 2018 6:03 pm

I just purchesed and installed a carter electronic fuel pump after reading many positive reviews of the pump on the Samba.

I installed it under the gas tank and replaced my fuel 1/4 " fuel line with 5/16 to match the pump input and output .

I installed a jegs fuel pressure gauge at the carb. It started right up and initially read 2.5 psi.

I thought that was a little low but it was the same pressure as my mechanical so it shouild be fine.

The next day i started it up and it only read about 1.5 psi , i drove it around and checked it again and it was up to 2.5 psi.

My buggy ran a little rough and seemed lean, but it was only 50 degress out today.

The gauge seams to read between 1.5 and 2.5 psi , 1.5 is to low.

Any ideas about what could be the problem?

I will drive it again tomorow it is suposed to be 60 out and see if its still rough.

I have a single weber 40 DCNF carb on a 2007 cc engine with w100 cam and 1.25 ratio rockers. It normally runs perfect.

Thanks for your help!

Sat May 12, 2018 8:25 pm

Is gauge on output of regulator?..... If it is you may have lousy regulator, or bad gauge, the Carter rotaty pump (GP60504) are rated at 3-4 PSI at full demand, you should NOT need regulator with these pumps....

Dale

Sat May 12, 2018 9:04 pm

I did this same setup last week using the Carter and a Jegs psi gauge. I used it on Dual Weber 44idf's using a regulator set at 3 psi. I started noticing the psi would drop to zero after about 10 min of idling although the engine acted normal. I called Carter to ask about it and they said the pump has an internal bypass in it so if you are not running a fuel tank return line it will start bypassing until demand picks up and you will see psi climb back up when the pump stops bypassing. I found I did not have to run a tank return line on this setup as the pump bypassing did not affect the engine demand. Carter said it would not cause harm to the pump by not running a return line. First time I used a Carter so we shall see. P4070.

Sat May 12, 2018 9:13 pm

Most of these complaints end up being cheap gauges, usually liquid filled.

If you want to test the fuel pressure, use a professional quality vac/fuel pressure testing gauge.

Sun May 13, 2018 5:20 am

oldschool5er wrote: I did this same setup last week using the Carter and a Jegs psi gauge. I used it on Dual Weber 44idf's using a regulator set at 3 psi. I started noticing the psi would drop to zero after about 10 min of idling although the engine acted normal. I called Carter to ask about it and they said the pump has an internal bypass in it so if you are not running a fuel tank return line it will start bypassing until demand picks up and you will see psi climb back up when the pump stops bypassing. I found I did not have to run a tank return line on this setup as the pump bypassing did not affect the engine demand. Carter said it would not cause harm to the pump by not running a return line. First time I used a Carter so we shall see. P4070.

Wow thats cool, I bought the p60505 which is internally regulated 3-4 psi so there is no need for regulator. I wounder if mine has an internal bypass as well. I went with this pump because CB sells it , air cooled sells it and i know alot of people use it. It looks like yours has a higher flow rate though. I a definitly experienceing the same issue though. It sounds like it maybe ok then.

I will drive it again today and see how it runs.

Sun May 13, 2018 5:34 am

modok wrote: Most of these complaints end up being cheap gauges, usually liquid filled.

If you want to test the fuel pressure, use a professional quality vac/fuel pressure testing gauge.

I was wondering about the accuracy of these gauges. I checked the old pump a couple of times with a cheap vac/fuel pressure gauge and with this jegs gauge it was 2.5 psi.

I decided to replace my glass fuel filter at carb with a preasure gauge. I liked my glass filter but i worried about failing.. I read about glass filters breaking and thought a fuel pressure gauge at the carb would be better.

Sun May 13, 2018 5:44 am

Those pressure gauges in the engine compartment are usually very inaccurate and really what good are they for monitoring purposes. Remove it and tee in your vac/pressure gauge for testing and if all is ok remove and move on.

Sun May 13, 2018 5:53 am

74 Thing wrote: Those pressure gauges in the engine compartment are usually very inaccurate and really what good are they for monitoring purposes. Remove it and tee in your vac/pressure gauge for testing and if all is ok remove and move on.

Good idea, i will check it with vac / pressure gauge. I didn't know these liquid gauges were so inaccurate. The box my fuel pumo came in was beat so i was worried i got a damaged fuel pump. The pump looked fine when i opened it , but was suprized Jegs would ship something in a smashed box. It was double boxed so i know it was not smashed in shipping.

Thanks everybody for the info.

Sun May 13, 2018 9:14 am

the other thing which will cause low output pressures are inlet restrictions. Typically the fuel tank vent, or the fuel tank filter. I personally remove the filter on every car I have, and regularly change the in line filter.

I have seen tank outlets (even with no filter) clogged 100% with rust. Blowing it back to clear it is a ghetto fix, and will leave you fixing the problem properly soon. Best to flush the tank.

Sun May 13, 2018 6:18 pm

[email protected] wrote: the other thing which will cause low output pressures are inlet restrictions. Typically the fuel tank vent, or the fuel tank filter. I personally remove the filter on every car I have, and regularly change the in line filter.

I have seen tank outlets (even with no filter) clogged 100% with rust. Blowing it back to clear it is a ghetto fix, and will leave you fixing the problem properly soon. Best to flush the tank.

The tank outlet conection is brand new 5/16 " with no filter on it. I don't think its a vent problem because it ran perfectly before i put the electronic fuel pump in.

At this point i am pretty sure i got a bad pump from jegs. The box was damaged when i received it .

The pressure varies between 0 and 2.5 psi at the carb . If he engine was running right would dismiss the gauge reading .

Also the pump is loud , i had friend listen to it that has the same pump and he says his was quiet.

I am calling Jegs tomorow and sending this pump back.

Mon May 14, 2018 1:22 pm

So I pulled my Carter electronic fuel pump today it's on its way back to JEGS and they're sending me a new one. But I couldn't resist hooking up my old mechanical fuel pump.

So I hooked up the mechanical fuel pump left the pressure gauge inline and put my glass filter back in line and the car ran perfect just like before I switch the pumps.

The issue I was having which is why I went to electronic up in the first place is that the mechanical pump was having trouble keeping up with demand at 70 mph .

So for example started the car up glass filter filled up with gas pressure was 2 1/2 PSI. Took about a 20-minute Drive jumped on the expressway going about 70 miles an hour no issues but then when I pulled off and parked it at my house. I noticed the glass was almost empty and the pressure was reading 0.

So neither pump is keeping up with the fuel demand , but the electric was worse than my mechanical.

I'm hoping that the new electric pump will work properly and I just got a bad one.

I have a vented 69 Dodge Charger gas cap on my dune buggy I am taking John's advice and I did drill out the vent size a little bit not sure if that will make a differance. I can't check the original vent because it's under the hood which is permanently attached.

Thanks everyone for your advice and help I'll keep you posted when I get to new pump

Mon May 14, 2018 5:21 pm

the stock pump is good for 160hp, so you have something else going on (a fuel restriction) you haven't discovered yet.

it's also pointed to when you said the new pump was loud. They are only loud if they are restricted on the inlet side.

Though I will say there are 2 different rotarys, they have the same PN but the country of mfg is different.

Mon May 14, 2018 6:55 pm

[email protected] wrote: the stock pump is good for 160hp, so you have something else going on (a fuel restriction) you haven't discovered yet.

it's also pointed to when you said the new pump was loud. They are only loud if they are restricted on the inlet side.

Though I will say there are 2 different rotarys, they have the same PN but the country of mfg is different.

Hi John, thanks for the info i was worried i bought to small of a fuel pump for my motor. When i told a friend that the pump had a flow rate of 30 g/hr he thought was low.

How big of a gas tank vent do i need? I know it is vented thru the gas cap , but i cant remember if there is an addition vent on tank. I did increase the size of the gas cap vent hole but have done anouther test drive yet.

Since the tank was completly drained and a new larger 5/16 fuel line conectiion was put in i can't fined a restriction there . Also i did not put a filter screen on the inside of the tank.

The pump is located directl under the tank and there are no kinks in the 5/16 fuel line.

The pump box said made in USA, it will be interesting to see what they send me.

Thanks, Greg

Mon May 14, 2018 7:16 pm

Tank does not need to big a vent, it just has to be big enough to break any seal that will cause a vacuum... The rate of fuel use per hour is a lot less than you think, if pump can do 30 gallons per hour, think of how far you drive in one hour at 70MPH bet you are getting better than 2.3 miles per gallon.... If you get 15 miles per gallon that means you are only using about 4.6 gallons per hour... If you get 20 miles per gallon your fuel usage is only 3.5 gallon per hour at 70MPH...As a guess your pump is running at about 15% of its rated capacity (do not totally rely on accuracy of my numbers though because I slept through math class in hi skool)... Your actual consumption rate is a lot less than pump capacity....

Early VW only has vented cap, later ones with all the smog crap has non vented cap....If you have vented cap on your tank there should not be a problem....

Dale

Mon May 14, 2018 7:58 pm

Dale M. wrote: It does not need to big a vent, it just has to be big enough to break any seal that will cause a vacuum... The rate of fuel use per hour is a lot less than you think, if pump can do 30 gallons per hour, think of how far you drive in one hour at 70MPH bet you are getting better than 2.3 miles per gallon.... If you get 15 miles per gallon that meana you are only using about 4.6 gallons per hour... If you get 20 miles per gallon your fuel usage is only 3.5 gallon per hour at 70MPH...

Your actual consumption rate is a lot less than pump capacity....

Early VW only has vented cap, later ones with all the smog crap has non vented cap....If you have vented cap on your tank there should not be a problem....

Dale

That makes sense to me, but i noticed the other carter pump people are using is 70gph. I friend of mine thought my fuel pump was tiny, but he is a V8 guy , LOL. I think his fuel pump was rated at 150gph and he had two pumps.

You answered my question about the venting and my gas cap vent should be adaquate. I have seen the larger tank vents on beetles so i wanted to make sure.

I probably got a bad pump , the box was damaged. I will see how it runs with the replacment pump.

My main concern is that it does't seem to get enough fuel at high speeds. It does 70 mph easy but i have never had it over 80mph. At 70 mph in 4th i am only at 3K, i should be able to blow past 80 easy.

Thanks for the advise., Greg
When i get off the express way my fuel filter is almost empty and now fuel pressure gauge it is around 0 psi.

I got figure out why it can't keep up.

Mon May 14, 2018 8:05 pm

Have you got stock screen in tank?.... Has it ever been changed.... Have you tried air pressure to blow out line from pump to carbs.... Is you fuel filter installed correctly...

Dale

Mon May 14, 2018 10:19 pm

I think it is the vent-what year and make is your car?

Tue May 15, 2018 3:52 am

sounds like your vent, drive without the gas cap on to rule it out

Tue May 15, 2018 4:46 am

Dale M. wrote: Have you got stock screen in tank?.... Has it ever been changed.... Have you tried air pressure to blow out line from pump to carbs.... Is you fuel filter installed correctly...

Dale

There's no screen in the tank, lines brand new 5/16 can blow through it easily, have a vented gas cap with a tiny hole in the middle for venting.

Tue May 15, 2018 4:52 am

Slow 1200 wrote: sounds like your vent, drive without the gas cap on to rule it out

I thought about doing that , not sure I want to do 70 miles an hour on the expressway with my gas cap , Lol