starts breaking up at 4500 rpm. - Page 3

Sean Marconette · 10-30-2015, 09:01 PM

May be a really stupid question but check that the return is not connected to the vent on the cell, as its a one way check. This would dead head the pump and the regulator, the check may allow some flow but I would be surprised.

partsbob67 · 10-31-2015, 09:18 AM

return is unblocked. -8 line for a vent line.

Jeff Niceswanger · 10-31-2015, 09:41 AM

Is this a Fast system ?

partsbob67 · 10-31-2015, 10:34 AM

nope. stock with a Anderson pms, then I hooked up my rpm extender, then I tried just my stock ecu. all acted the same.

Kegracing · 10-31-2015, 02:50 PM

You might try putting some foam in the cell... I don't have a lot of experience with injection, but sure sounds like it is running out of fuel or getting air in it.
With higher pressure of injection and a lot of return at high pressure, if it is putting air in the cell, getting air in the line, it will cause headaches...

Keep working on it, you will find it.

Ken
Stock 412

partsbob67 · 10-31-2015, 03:16 PM

thanks. I will try that.

buzzinhalfdozen · 11-01-2015, 05:22 PM

Bob, does your return have a dip hose inside the tank so it's putting the fuel in below the fuel level? Personally if you were getting air in the system I would think you would be able to hear the pump surging and you would see pressure fluctuations. Have you ever looked in the tank with pump running to see if it looks like the fuel is being aerated? When you say it starts to go lean, does it go a full number or just a few points lean and if your bring it back below 4500 does the AFR come back to normal?

Bob Shaw · 11-02-2015, 08:53 PM

Is the fuel cell outlet facing to the rear of the car?

partsbob67 · 11-02-2015, 10:09 PM

yes fuel outlet to the rear. return is right above it on the top of the cell. no foam so I think we have a winner with the airiation from the return. gonna put a tube in there and see how that works.

Mike Pearson · 11-03-2015, 01:04 PM

Quote:

Originally Posted by partsbob67

yes fuel outlet to the rear. return is right above it on the top of the cell. no foam so I think we have a winner with the airiation from the return. gonna put a tube in there and see how that works.

For testing purpose dump the return line into a separate container. That would fully eliminate any aeration from the return

10-30-2015, 09:01 PM	#21
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 790 Liked 275 Times in 76 Posts	Re: starts breaking up at 4500 rpm. May be a really stupid question but check that the return is not connected to the vent on the cell, as its a one way check. This would dead head the pump and the regulator, the check may allow some flow but I would be surprised. __________________ Sean Marconette 84 Mustang 5060 SS/N

10-31-2015, 09:18 AM	#22
partsbob67 Member Join Date: Apr 2005 Location: rohnert park,ca Posts: 414 Likes: 11 Liked 79 Times in 11 Posts	Re: starts breaking up at 4500 rpm. return is unblocked. -8 line for a vent line. __________________ bob beals 7244

10-31-2015, 09:41 AM	#23
Jeff Niceswanger Senior Member Join Date: Jul 2003 Posts: 870 Likes: 673 Liked 962 Times in 352 Posts	Re: starts breaking up at 4500 rpm. Is this a Fast system ? __________________ Jeff Niceswanger 3740 SS

10-31-2015, 10:34 AM	#24
partsbob67 Member Join Date: Apr 2005 Location: rohnert park,ca Posts: 414 Likes: 11 Liked 79 Times in 11 Posts	Re: starts breaking up at 4500 rpm. nope. stock with a Anderson pms, then I hooked up my rpm extender, then I tried just my stock ecu. all acted the same. __________________ bob beals 7244

10-31-2015, 02:50 PM	#25
Kegracing Member Join Date: Jun 2002 Location: Red Oak, TX Posts: 441 Likes: 0 Liked 0 Times in 0 Posts	Re: starts breaking up at 4500 rpm. You might try putting some foam in the cell... I don't have a lot of experience with injection, but sure sounds like it is running out of fuel or getting air in it. With higher pressure of injection and a lot of return at high pressure, if it is putting air in the cell, getting air in the line, it will cause headaches... Keep working on it, you will find it. Ken Stock 412

10-31-2015, 03:16 PM	#26
partsbob67 Member Join Date: Apr 2005 Location: rohnert park,ca Posts: 414 Likes: 11 Liked 79 Times in 11 Posts	Re: starts breaking up at 4500 rpm. thanks. I will try that. __________________ bob beals 7244

11-01-2015, 05:22 PM	#27
buzzinhalfdozen Senior Member Join Date: Sep 2006 Location: Bellevue Ohio Posts: 984 Likes: 0 Liked 11 Times in 8 Posts	Re: starts breaking up at 4500 rpm. Bob, does your return have a dip hose inside the tank so it's putting the fuel in below the fuel level? Personally if you were getting air in the system I would think you would be able to hear the pump surging and you would see pressure fluctuations. Have you ever looked in the tank with pump running to see if it looks like the fuel is being aerated? When you say it starts to go lean, does it go a full number or just a few points lean and if your bring it back below 4500 does the AFR come back to normal? __________________ Joe Buchanan SS/BX 3117

11-02-2015, 08:53 PM	#28
Bob Shaw Member Join Date: Jan 2002 Location: Sedalia, Mo Posts: 435 Likes: 318 Liked 295 Times in 60 Posts	Re: starts breaking up at 4500 rpm. Is the fuel cell outlet facing to the rear of the car? __________________ Bob Shaw V/SA 515

11-02-2015, 10:09 PM	#29
partsbob67 Member Join Date: Apr 2005 Location: rohnert park,ca Posts: 414 Likes: 11 Liked 79 Times in 11 Posts	Re: starts breaking up at 4500 rpm. yes fuel outlet to the rear. return is right above it on the top of the cell. no foam so I think we have a winner with the airiation from the return. gonna put a tube in there and see how that works. __________________ bob beals 7244