Fuel Pump Problem?

[LaryHill]

The electric fuel pump has started to run constantly in my '71, 1.9 GT. I'm not sure if I should be looking at the float bowl or my DGAV 32/36. I noticed that when I turn the key without starting the engine, the pump will not shut off, and I can see fuel dripping in the primary chamber. The fuel pump is an AC EP42 (12V). Can't find any specs for it. I'm about to go out and purchase a low pressure (2.4-4.5psi) pump. Am I headed in the correct direction or should I be looking at the carbuetor? Looking for guidance!

Larry

[pvcar]

well to post on fuel pumps i had purchased one about 3 months ago from kragen auto parts and installed it near the rear of my gt and wired it to the key on side of the fuse box pump worked great but with only about a 100 miles on it the pump started to not work on occasion, so i took it back since that pump had a lifetime warranty only yhing is they dont make it anymore and no one has one, so i had to exchange for there universal fuel pump which is pretty nice i think, and is very silent when rubber mounted near the back of the gt.

[kwilford]

Originally Posted by LaryHill I'm about to go out and purchase a low pressure (2.4-4.5psi) pump. Am I headed in the correct direction or should I be looking at the carburetor? Looking for guidance! Larry

The Weber and Solex carbs won't tolerate more than 3.5 psi. If the pump puts out more, install a good quality fuel regulator.

[pvcar]

the pump from kragen is rated from 3 to 5 psi i believe is what the box said.

[kwilford]

Originally Posted by pvcar the pump from kragen is rated from 3 to 5 psi i believe is what the box said.

Which will flood a Solex or Weber carb

[pvcar]

well i have the weber 32,36 instaled on my gt and am running the pump for the past 3 days in varying weather and conditions and load conditions and hasnt seemed to hinder my performance, and it starts up cold like that and like our gts are known some what not to start when hot but doe fine in hot conditions too. guess its luck maybe.

[LaryHill]

I guess the solution is with changing the fuel pump. I've been trying to find a local outlet for a pump with the correct specs. The best I could find was 2.5 to 4psi. I will wait until Monday and call OGTS, I'll see what they can offer.
My other concern was with the carbuetor. In the fuel flow system, will the pressure that is generated from a full float bowl trigger the electric fuel pump to stop?
Larry

[kwilford]

Otto has recommended the following pump:

Carter (Federal-Mogul) P60504 electric fuel pump

as described in this thread:

http://opelgt.com/forums/showthread.php?t=4139

and you might also read his thread on fuel pump safety shut off switches at:

http://opelgt.com/forums/showthread.php?t=3306

[kwilford]

And here is a pump that was recommended by someone on the list from JC Whitney:

http://www.jcwhitney.com/autoparts/E...CatalogDisplay

[pvcar]

it does not seem like the back pressure from it pumping to much fuel for the amount being used would cause a regualr pump to shut off, i could see it maybe causing it to fail due to the pressure build up but ive never heard of that happening how good of condition is the weber in? could something have failed inside the carb just a thought.

[tekenaar]

Originally Posted by kwilford And here is a pump that was recommended by someone on the list from JC Whitney: http://www.jcwhitney.com/autoparts/E...CatalogDisplay

Sorry, but no matter how well you isolate this pump when mounted near the rear (where it should be!), it's NOISY . . . irritatingly so!!!

If you've checked that you DON'T have excessive crankcase pressure, as suggested in an earlier post in this thread, and still want to go with an electric, low-pressure FP, I would suggest this one.

[pvcar]

well the way i mounted mine was by using a rubber mount almost exactly like the one that is used on the gts lower radiator mount a circular piece of rber with two threeaded bolts on each side i drilled hole underneath almost directly above the axle bolted on the mount then made a mounting plate out of some pretty thinck sheet metal i had laying around bolted pump to sheet metal then bolted sheetmetal to other side of rubber mount, the only time u can really hear it is if u get in the car turn the key to on and not start the car u can here this very faint hmmmmmmmm noise but once u start the engine u cant even hear it. ill take pics of how i did it and post um.

[baronbors]

I put the new electric fuel pump in last week (2.5 psi) Seems to be working great. No more pumping for 5 minutes when cold to get it started. Now I am comtiplating bypassing the old fuel pump entirely. Is this a good idea? How would it be done? Can I merely re-route the fuel line leaving the old pump intact? Think I need some guidance on this

[jeff denton]

I can't help you with Opel-specific fuel pressure requirements as mine uses the good old Carter electric pump (as do all my rigs) and a Holley carburetor.
But I do want to once again beg you all to make sure you understand and install a relay to cut the pump off when you lose oil pressure, such as might happen if you crash your car and leave the key on in those awful moments immediately following the crash.
Because if you don't, the crash will very likely be quite inconsequental (sp?)
compared the tremendous fire being fed gasoline at 7psi and 150 gph.
Any questions? Feel free to let us show how to do it (again) or use the search feature, as it is all there.
I have a friend with severe burn scars, has had lots of surgery on his face but a long way to go. He was in a Chevy pickup (fuel tanks outside the frame rails) that got T-boned. Twenty years ago. Right, had nothing to do with fuel pumps, but, think about it.
Please.

[baronbors]

Originally Posted by jeff denton But I do want to once again beg you all to make sure you understand and install a relay to cut the pump off when you lose oil pressure, such as might happen if you crash your car and leave the key on in those awful moments immediately following the crash. .

I double switched it- The defroster switch is now my secret fuel pump switch along with a MG inertia cut off switch courtesy of evilbay. But I still need to know how to eliminate the original fuel pump?

[GTJIM]

Originally Posted by baronbors I double switched it- The defroster switch is now my secret fuel pump switch along with a MG inertia cut off switch courtesy of evilbay. But I still need to know how to eliminate the original fuel pump?

The inertia switch is a good idea. Pays to remove the original mechanical pump from the fuel circuit by simply using a piece of fuel hose. You can then remove the old mechanical pump and make up a block-off plate to seal up the mounting hole or just leave the old pump there, as long as it is not leaking oil. If the old mechanical pump is left in the fuel circuit, sooner or later the diaphram will rupture and your nice new electric pump will just pump fuel into the sump or dump fuel on the ground through the leak.

[soybean]

I agree with GtJim. Eliminate the pump. I got a fuel pump block off plate from OGTS when I went to a electric fuel pump. At the time I had everything out from under the car, I used 5/16 steel tubing and ran it from rear to front and replaced the old plastic fuel line. When I got in the engine compartment, I ran above the frame rail with the tubing, cut apx 8 in out of the tubing, ran the 8 in cutout with 5/16 fuel line. The idea being, if I ever wanted to go back to the mechanical fuel pump, all I would need to do was splice into the cut out with new fuel line. The rest of my steel fuel line was fed through the radiator support and up to the front of the car, through a two row Summit Oil/Fuel cooler, around to the passenger side through the radiator support and up the side to end within 10 inches of the carburetor where it goes back to rubber fuel line to the carburetor. Jarrell

[tekenaar]

Originally Posted by baronbors I double switched it- The defroster switch is now my secret fuel pump switch along with a MG inertia cut off switch courtesy of evilbay. But I still need to know how to eliminate the original fuel pump?

From a much earlier post attached pic, how about THIS!

[soybean]

That's the plate. And there's the other way to shut off power to the fuel pump. That was the way I was going, even have all the parts, but failed to loosen the plug that the parts go in before painting engine block with POR 15 and Engine Enamel. It's locked in forever now. So I'm going with a resetable inertia switch on this engine. I won't make the same mistake twice. Jarrell

[tekenaar]

Originally Posted by soybean That's the plate. And there's the other way to shut off power to the fuel pump. That was the way I was going, even have all the parts, but failed to loosen the plug that the parts go in before painting engine block with POR 15 and Engine Enamel. It's locked in forever now. So I'm going with a resetable inertia switch on this engine. I won't make the same mistake twice. Jarrell

How about a T-fitting at the OP/light sender? More than one way to skin a cat.

[soybean]

I thought about that Otto, but had gone too far by that point, so I'm going with a resetable inertia switch. Gotta learn from your mistakes. "Red one" will be right. jarrell

[jeff denton]

Jarrell, what are you running for an oil pressure gauge/idiot light?

[soybean]

Jeff, I'm running the original sending unit. In fact I sprung big bucks for a new one from OGTS. I've got a Sprint Exhaust on this engine. Jarrell