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Car is surging at the big end of the track...help #1057812 08/20/11 09:54 AM 08/20/11 09:54 AM
Joined: Apr 2006 Posts: 58 Ohio S SteveR OP member
SteveR OP member S Joined: Apr 2006 Posts: 58 Ohio	I had my car at the track last night for a test n tune night. Car launches well and runs through 1st gear ok, but in 2nd gear above 4000rpm, and into 3rd it is surging very bad. Only recent change was a swap to a higher volume fuel pump. Anyone have any suggestions? Here's my combo 73 challenger 0.030 over 360, 9.8:1 compression 0.477 lift cam Eddy 750 performer carb, air gap intake. Eddy performer fuel pump (110 gal/hr) Stock 5/16 fuel line from tank to carb. Stock electronic ignition 727 auto, 8 3/4 rear w/ 3.55 gear.

Re: Car is surging at the big end of the track...help [Re: SteveR] #1057813 08/20/11 09:58 AM 08/20/11 09:58 AM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Lean

Re: Car is surging at the big end of the track...help [Re: MR_P_BODY] #1057814 08/20/11 09:59 AM 08/20/11 09:59 AM
Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again Moparnut426 I Live Here
Moparnut426 I Live Here Joined: Mar 2007 Posts: 12,013 Finally a HUSKER again	Beat me to it Mr P I was gonna say LEAN Kasey

Re: Car is surging at the big end of the track...help [Re: Moparnut426] #1057815 08/20/11 10:40 AM 08/20/11 10:40 AM
Joined: Mar 2004 Posts: 2,475 SW Ohio C cgall top fuel
cgall top fuel C Joined: Mar 2004 Posts: 2,475 SW Ohio	Mechanical pumps are prone to vapor lock. Insulate your fuel line and spray your pump down with a garden sprayer between passes.

Re: Car is surging at the big end of the track...help [Re: cgall] #1057816 08/20/11 11:05 AM 08/20/11 11:05 AM
Joined: Feb 2004 Posts: 1,093 Long Beach, CA Mike Swann super stock
Mike Swann super stock Joined: Feb 2004 Posts: 1,093 Long Beach, CA	Put the old pump back on, lol. 8.30's @3400 lbs

Re: Car is surging at the big end of the track...help [Re: SteveR] #1057817 08/20/11 11:11 AM 08/20/11 11:11 AM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	By chance did you kink (or reduce) the line when you changed the pump

Re: Car is surging at the big end of the track...help [Re: MR_P_BODY] #1057818 08/20/11 01:57 PM 08/20/11 01:57 PM
Joined: Nov 2009 Posts: 3,082 St. Paul , Mn. tubtar master
tubtar master Joined: Nov 2009 Posts: 3,082 St. Paul , Mn.	I'd lose the 5/16th fuel line............and the small diameter pick up in the tank for starters.

Re: Car is surging at the big end of the track...help [Re: SteveR] #1057819 08/20/11 02:04 PM 08/20/11 02:04 PM
Joined: Jul 2008 Posts: 30,478 Florida STAYcation dOc ! The village idiot's idiot
dOc ! The village idiot's idiot Joined: Jul 2008 Posts: 30,478 Florida STAYcation	x 22 ... lean. But it is because of low fuel-pressure. You have major fuel-delivery probs.

Re: Car is surging at the big end of the track...help [Re: MR_P_BODY] #1057820 08/20/11 02:55 PM 08/20/11 02:55 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: Lean Is your fuel pressure gauge located where you can see it when it occurs? Fastest 300

Re: Car is surging at the big end of the track...help [Re: Crizila] #1057821 08/21/11 01:20 PM 08/21/11 01:20 PM
Joined: Apr 2006 Posts: 58 Ohio S SteveR OP member
SteveR OP member S Joined: Apr 2006 Posts: 58 Ohio	No. Only gauge is currently mounted on the engine. I'm looking at adding one inside so I can see it. Checked the fuel line yesterday and didn't see any kinks. One small section of rubber hose between the frame rail line and pump is soft, so I am going to replace it with a stiffer hose. Could this be collapsing since it is on the suction side of the pump?

Re: Car is surging at the big end of the track...help [Re: SteveR] #1057822 08/21/11 02:13 PM 08/21/11 02:13 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: No. Only gauge is currently mounted on the engine. I'm looking at adding one inside so I can see it. Checked the fuel line yesterday and didn't see any kinks. One small section of rubber hose between the frame rail line and pump is soft, so I am going to replace it with a stiffer hose. Could this be collapsing since it is on the suction side of the pump? I have seen cheap carb type hose collapse... I like to use EFI rubber hose... it has a Viton liner in it so its stiffer... but anything is possible

Re: Car is surging at the big end of the track...help [Re: SteveR] #1057823 08/21/11 02:22 PM 08/21/11 02:22 PM
Joined: Feb 2005 Posts: 28,312 Cincinnati, Ohio Challenger 1 Too Many Posts
Challenger 1 Too Many Posts Joined: Feb 2005 Posts: 28,312 Cincinnati, Ohio	Did you increase the inlet line sizing and pickup size inside your fuel tank, if stock with the higher volume pump? Cavation is a big problem with hi volume pumps.

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