The electric fuel pump on my EFI slant is so noisy you can hardly hear the exhaust, even thaough it has no mufflers at this point. Does anyone know of a good, cheap electric fuel pump that is also quiet? What I have is Bosch, marketed by Accell. All the ones in Jegs are either VERY expensive ($400), or look essentially like the one I have. Who out there has experience with a pump that they know is quiet? It must put out 45-50 PSI, and be rated for up to 400 hp. That's the other thing, all the other pumps listed in Jegs are for 2000 HP applications. The six injectors are 30 LBS per hour if that helps define the needed volume.

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

Try looking on the Megasquirt website for OEM options, espeically in Lance's "Megamanual". 90s Ford trucks??

I've heard mounting them on rubber-isolated mounts also helps a lot.

Lou

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Home of Slant6-powered fun machines since 1988

Thanks for the tip. I have the pump currently mounted on rubber muffler hanger straps. It's still LOUD. I am begining to suspect that the fuel pump is behind the mysterious random lean conditions that I seem to experience once in a blue moon. All of a sudden the AF ratio will go way lean, and all the electronic feed back seems to be within expected parameters. The one variable I cannot monitor here is fuel pressure. I am wondering if it drops down from the pump, and thus goes beyond the limits of what the regulator will, or can control. What kind of fuel pump are you running Mr. 270?

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

Are you running a stock tank. I'm working on EFI and as a test run am using a low pressure pump(that supposedly would suck better), and I've had quite a few problem. When I go to EFI I'm going to use a fuel cell mounted in the trunk with sump feed on it and force feed the pump. With a stock tank to me it seems as though you'd always have to be full in order for things to work right. My pump is very quiet when it's getting enough fuel, when it's starving I can hear it above my Music and exhaust.

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

Backing up Mr. Shiva - I assume fuel slosh/level is not to blame?

I won't have my MPFI system running until sometime in May. I have the MSD external (45GPH, I think?) pump from Summit. Don't know how loud it is. Pretty quiet sitting on the car not pumping for the last 8 months...

Lou

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Home of Slant6-powered fun machines since 1988

I'm not saying it's an inherant flow in the stock tank, it is a problem with fuel/slosh, and I'm saying that if he's using a stock tank it could have been very easy to get the pump in a bad spot, though equally possible to get it in good. I'm saying that his pump could be starving because it might not be fed well enough by the stock tank if the fuel pump isn't in a good spot(even in a good spot if he used the stock pickup there's still quite an up-turn in the plumbing). I'm not sure if it's the case, just a thought. I know that a lot of pumps when they start running out of fuel get crazy loud, but once they're lubricated they get quiet again.

At least, this has been my experience.

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

Now that is a thought. The pump is down low on the frame rail, below the level of the tank. It is being fed by the same line that fed the stock pump, so one would think the design of the gravity feed to the stock pump would still work all right to get a prime to the electric pump. I will definately look at that idea though, to see if maybe the pump is not getting a full supply line of fuel to work with. I will lok for restrictions in the line. It does rise first, and then fall back down to the rail, just like the stock line.

It could just be masked by other road noise, but it seems quieter once I get going. Witht he return line, you would think the pump was putting out the same all the time, no matter what was being passedd through the regulator. At any rate, I have convinced myself the pump is not reliable, so now I am not driving the car until I get this sorted out.

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

I went on line and looked at the MSD pump from summit. It essentially the same as the Accel pump, probably made by the same company. I wrote to Rance, who I bought the pump from, and he said these pumps are NOT designed to pullk through a regualr pre filter. I DO have it behind a regular prefilter, so maybe I ruined the pump myself. Maybe it was running somewhat dry all the time. I will take the filter of, and see if things get better.

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

When I did my efi, I kept hearing, "don't skimp on the pump and fuel delivery system because it'll create annoying little problems down the road". My Bosch pump makes some noise as well . . . I can hear it chatter but its not that loud.

Lou I missed you a couple of weeks back in RTP and now I'm in Bangkok. Its a little closer but still thousands of miles away.

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Cheers!
Al T

Vader - What do you mean by a "regular" prefilter? I have mine running through a 3/8" standard carb filter (on tank side). We'll see how it sounds...

Al - Bummer I wasn't there to hang out. Tried sending you an email recently about an M90 blower I bought - maybe old address? Should start to play with that this summer. Hopefully we can hook up in person sometime soon.

Cheers,

Lou

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Home of Slant6-powered fun machines since 1988

All I know is What Rance told me. I will look for his e-mail tomorrow at work and see if he has more to say about that. I have the same kind of filter you do.

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

Vader,
I believe that I'm using the same pump that you're using. It is an Accel pump that I got from Rance. I definately hear it when idling, and I don't want to give the impression that it is real quite, but I don't notice it once the car is moving. This was the case even whan I used a muffler before installing the turbo. It's about five years old now. I also have a pre-filter and if I'm recalling correctly it was recommended in the literature that came with the pump. I have always used a 3/8" line but only installed the 3/8" pick-up when I went to the turbo.
One thing that does bother me, and that I haven't been able to resolve, is a very rapid "flutter" in my fuel pressure gauge that seems to occur quite often at idle. This doesn't seem to affect how the engine runs when it happens. It has occured off and on for years now so I don't think the pump is failing. Have you ever noticed any of this pressure "flutter"?
Bob D

Hi Bob. I do not have a fuel pressure gauge I can see while in the car. What kind of gauge do you have. Is it electronic with a sending unit. I do not want fuel in the cockpit. What I have noticed is once in awhile the AF ratio will go quite lean. I am blaming this on the pump , since all the sensor feedback seems to be in the normal range when this occures. I just shrug my shoulders, shut the engine down, and things seem to be back to normal the next time I start the car. Rance did tell me he does not recommend a filter in front of the pump. I would not have done a pre-filter unless I read it, or was told to do it by someone. But right now, he is saying, take off the pre-filter, and put an EFI sock on the pick up tube in the tank. It's really frustrating to be this far with this project, and still feel like I can't just drive it. I wish someone could recommend a known, quantity pump that I could apply that I could count on to work well and be quiet as well.

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69 Dart Swinger, 230 ci slant, t-5 five speed, intercooled turbo, 4 wheel disk brakes, tubular upper control arms.

The fuel pressure gauge that I use attaches to the fuel rail. I believe it was made by Accel. I can only observe it from under the hood.


When your A/F gauge reads lean does it stay lean for a few seconds or is it rapidly "swinging" back and forth? The rapid "swing" is normal when you are running closed loop and the feed back circuit is constantly correcting for the ideal mixture.
Bob D

A couple of comments based on my non-slant EFI projects.

I have only used in tank pumps with the stock EFI filter sock. Those installs use a stock "bucket" that the return line dumps into to keep slosh and a low tank from letting the pump run dry. Down side to the bucket is on hot days that fuel is getting pretty hot when the tank is low. (Eric, your situation sounds like it needs a bucket)

The Impala SS crowd uses the Walbro in tank pump up to 500 hp. They seem to last as long as stock pumps. They utilise the stock EFI sock. I haven t used one because the stock pumps seem to work fine in my applications. ( 350 hp, 375tq pulling a loaded trailer in 2 feet of snow/mud in low range 1st gear,,,,1.5 mpg)

A good pressure regulator is key to constant pressure/flow. I use an adjustable regulator and can reduce A/F ratio bounce by optimizing pressure.

I had to go to larger injectors because my stock injectors "cycled out" at high flow conditions.

My A/F ratio bounces more during a learning cycle. When I go from a "big load" to empty the puter takes a while to relearn and will "bounce". The same occurred on a recent road trip when I used Wyoming/Dakota ethenol fuel. It took 1/2 a tank to "relearn" regular fuel.

In tank pumps are far quieter than external pumps. I have an external Carter on our mudbogger that iI can hear through the open header noise. The same motor combo in my work truck is barely audible due to the in tank pump.

I use an in tank sock and after pump EFI filter in all my applications. The stock GM sock seems fine.

I have considered an inline cooler in my return line.

I have experienced a faulty/sticky pressure regulator causing low pressure under heavy load conditions. (too much fuel bypassed)

Flogging to learn...learning to flog. Hope this helps.

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Yeah....Im the one who destroyed this rare, vintage automobile.....