New fuel pump, causing Flooding

[Iowa409]

I spoke to Don today, I had a Summit fuel pump rated at 110 GPH, 6-8 PSI with an internal pressure shut off valve.

My car was pretty dialed in and we were getting it sounding pretty good.

I found a fuel leak on the housing of the fuel pump, who builds a fuel pump out of cast aluminum, best I can figure is at the outlet port I must have overtightened the fitting, last year, creating a crack, but I didn't notice it, now that the car is running, engine in place the vibration/over revving, I am sure I've been stressing it, lol

SO here we are, I go to ORiley's and buy part number M23017 fuel pump, says direct fit for 409/340.
Flow Rate : 50 GPH, Pressure Rating : 6PSI

So in my opinion and talking with Don, my flows and pressure is much lower than the original, and my lower HSP motor should respond fine to that, I agree with his Thinking, makes sense.

On re-firing the engine, suddenly the Brand new Edelbrock AV2 1906 is flooding the heck out of itself, literally dripping fuel, heavy at the throttle levers/base/carb base.

The only thing that changed was the fuel pump??? I should add, and I forgot to tell Don this, the new fuel pump has a inlet and a outlet port obviously, but there is a third port, a vent maybe? it had a protective cap on it, so I left it on, maybe its got to have ability's to breathe and I am doing something wrong there?

Done had some great ideas to check, 1 check output pressure at fuel pump, I am going to get a lower scale pressure gauge this morning to test that, good starting point.

He also thought maybe some crud or debris up in the needle area, I'll keep ya all posted on that test, should be later today.


The joys of working out the bugs to make it a reliable dependable car, after a major overhaul...........

 

[Iowa409]

I think this tester will do the trick.

https://www.oreillyauto.com/detail/...evrolet/impala?q=fuel+pressure+testing&pos=14

 

[tenxal]

#1 Replace needle&seats and adjust floats. Todays fuels are hard on them, especially after sitting a while.
#2 Check fuel pressure

With todays fuels, we've found it best to run the carb(s) out of fuel if it's going to sit for a while before being started. If you have the original 4GC carb on that 409/340, the Delco spring loaded needle and seat assemblies can be helpful.

 

[IMBVSUR?]

I would check the seat first. I just went through my quick fuel carb. I kept everything clean and never touched the seats. Flooding just like you speak of occurred. Rear bowl seat was the culprit. Yes they could have put the wrong PSI pump in the wrong box, so eventually you will want to check it. However, don't over think it until you need to.

 

[Don Jacks]

That cap is covering a vent,unplug it after checking the out put and recheck.The purpose of that cap is to bleed off fumes in the event of a diaphram rupture.That was commonly used in boats there there would be a line that attached to that nipple and run to the flame arrester.Fun fact;It can also be used as a boost reference to increase the fuel pressure in a low[under 8 psi] boost by attaching a line from the fuel pump to the "hat" for your blow thru carb. As I said last night,pull that inlet screen and check for debris before removing the carb top.

 

[427John]

I found a fuel leak on the housing of the fuel pump, who builds a fuel pump out of cast aluminum,

Most carter and AC pumps were made out of cast aluminum too,but I know what your saying some of those bling bling shiny pumps are made out of some pretty questionable looking castings.I don't know if its a different casting process or different alloy,but you can tell they're trying to approximate the look of the good billet body race type mechanical pumps with a cheap casting.

 

[Iowa409]

K guys just got home from work, stopped by Nappa to get a fuel pressure tester, Drum roll..........17 PSI out of the stock, rated 50 GPM/6.0 PSI fuel pump, stands to reason it would be blowing the seats right off the port, just letting it flow.

I could change it, its one day old, lol, could add a adjustable fuel regulator, dial it down, SERIOUSLY who needs these extra product failure to add to the work, lol

 

[Iowa409]

Done messing with it,
I am going to order this regulator and be done with it, should do it.




https://www.jegs.com/webapp/wcs/sto...&submodel=&engine=&Nrpp=&No=&persistYmm=false

 

[MRHP]

I would change the pump out. Less messing around.

 

[DonSSDD]

I think the over rated pressure in mechanical fuel pumps is pretty common these days. No quality control. Most of you racer guys are using fuel pressure regulators?

 

[Iowa409]

Yes that’s logical, 1 day old, failed on start up.
I save $85.00. If it was putting out correct PSI probably would not been an issue.

These fuel pumps are pain in the arse.
I had better luck once I got the cam rod deeper back into the block. I will say it’s less stressful to put them on,,while on the engine stand for sure.

 

[Iowa409]

I think the over rated pressure in mechanical fuel pumps is pretty common these days. No quality control. Most of you racer guys are using fuel pressure regulators?

True I think that’s easier for me to put the regulator on. BUT my brain is telling me makes no sense to spend $80 more to make the new defective fuel pump work correctly.

now the kicker will be, if I pick up the warranty replacement fuel pump tomorrow and it is putting out anything other than 6 psi, then I’ll be doing it a 3rd time.

 

[IMBVSUR?]

Yes that’s logical, 1 day old, failed on start up.
I save $85.00. If it was putting out correct PSI probably would not been an issue.

These fuel pumps are pain in the arse.
I had better luck once I got the cam rod deeper back into the block. I will say it’s less stressful to put them on,,while on the engine stand for sure.

I could not agree with you more about the engine stand, or at least a lift. I have changed several on my back under the car. The last one I did on my impala made me swear I would never do it on the ground again. Fought me like you wouldn't believe. I guess it will be pay to play on some things for now on. You listening James This is your chance to be that mobile mechanic you always wanted to be and see the nation

 

[Tim]

I had a new pump and tested the pressure up front. It was advertised at 6-7 psi and put out 23. I put a regulator on it and all is good. Could have kept changing them but it was pointless. Local engine shop said none of the new were accurate.

 

[MRHP]

My Edelbrock fuel pump has been flawless for 20 years, drag race and all. Don’t mask a problem with excessive complications. Just my opinion.

 

[DonSSDD]

My Edelbrock fuel pump has been flawless for 20 years, drag race and all. Don’t mask a problem with excessive complications. Just my opinion.

I wonder if the news ones are as good? I am a cynic about anything new, my first thought is it’s possibly junk.

 

[mark johnson]

I recently disassembled an Edelbrock fuel pump to clock the inlet/outlet locations and found a very nasty large chunk of casting flash ready to break off and end up who knows where!

 

[Don Jacks]

I've heard about some of these mechanical pumps being crazy high over the last couple of years.Now here's two in the last six weeks or so.When Mike told me about a carb that went from running good before the fuel pump was replaced to flooding my first thought was what's the pressure on the new pump.

 

[Jim Sullivan]

I've been using an Edelbrock pump since assembling my 409, never a problem.

 

[Iowa409]

I've been using an Edelbrock pump since assembling my 409, never a problem.

Jim I am looking into a #1721 right now, they are scarce now days, now they are pushing the 10 psi with a external regulator.

I just talked to my parts house and I am not sure I want to put another Precision Brand # M23017 on there, its to much work to guess and hope I'll probably have to eat the cost of the original pump because of age/time during build.

I do see in the specs that the edelbrock is rated at 110 GPH, the same as the Mr. Gasket pump I had on there, that cracked.
I see the Precision pump is rated at 50 GPH

Decision, decisions.....