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Author Topic:   fuel pressure problem
racedad21
Dirt Newbie

Total posts: 2
posted January 29, 2005 03:47 PM  
I have a new Barry Grant 15psi pump and bypass plate and can only get 7lbs with the motor rpm's up and it won't get less that 3 1/2 at idle with the bypass wide open. I'm not worried about the idel but it's the up rpm's that bother's me I've changed the gauge and have the same results and also the filter and I also have the gauge hooked up without a isolator. When I first put it on the car everthing worked fine except the shaft on the bypass was leaking so I sent it back to Barry Grant for repair the leak is fixed but now I have another problem has anyone been through this?

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44nymod
Dirt Maniac

Total posts: 120
posted January 29, 2005 05:00 PM  
racedad21 I went through this for a year. Barry Grant told me it was the fuel pump, so I rebuilt it. Again same problem Edelbrock told me I didn't rebuild it right, so I bought a new pump. I ended up with three pumps and nothing improved. I saw the belt drive pump by Ron's for Imca type Mods and bought it with a new regulator that has dual adjustments for high and jets for idle and let me tell you I have great pressure high 12 lbs at 3000 rpms and 3 lbs at 1000 rpms. Works great! This system costed me around $400. If I would of done this sooner I would have saved myself headaches and $$$. Listen to someone that has been through the same problem buy a belt pump you won't regret it!

holeshot
Dirt Maniac

Total posts: 119
posted January 29, 2005 08:45 PM  
I run the 9 pound pump with no regulator no bypass and have not had any problems. Idles at 6 psi and runs at about 9 1/2 psi at 3000. 13 to 1 383 @ 7000 rpms on alky.

dirtracer14
Dirt Forum Champ
Total posts: 1261
posted January 29, 2005 09:37 PM  
What happens if you unhook the plate rod from the throttle and close the ball valve what is the presure then? Might not be closing the valve all the way so it will not show 12 or 15 pnds.

Dustejr73
Dirt Maniac

Total posts: 177
posted January 30, 2005 10:25 AM  
after many burned 406 alky motors and a stack of "bad" mech fuel pumps i went to a ron jones belt drive pump last year and have had absoultely no problem. they are a great hassle free piece.

jason lee
Dirt Roller

Total posts: 10
posted January 30, 2005 09:11 PM  
where did you find the belt drive pump for 400 dollars? thanks

chomme
Dirt Freak

Total posts: 300
posted January 30, 2005 10:54 PM  
What are you guys using for a lower radiator hose with the ron's belt drive pump. I have the block mount pump but can't seem to find a lower hose that will clear the pump.

Thanks
Terry

A&M Motorsports
Dirt Maniac

Total posts: 117
posted January 31, 2005 07:13 AM  
racedads rules do not allow a belt driven pump so he is stuck with what he has. A lot of folks use the 9 psi pump but it's a dangerous experiment if it don't get enough alky on the big end.

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Artie Perilloux
A & M Motorsports

nvracer
Dirt Maniac

Total posts: 127
posted January 31, 2005 09:15 AM  
Check this out. Anyone try these I know they are new. Kind of pricy. http://www.racepumps.com/

Kromulous
Dirt Forum Champ
Total posts: 796
posted January 31, 2005 11:00 AM  
Well, if you can try a Larger fuel log, and a smaller return line, smaller I.D.

If you have to run a mech pump and got some parts around to try it thats what i would do.

Also check the gauge if you got a spare laying around.

waltonjr1
Dirt Forum Champ
Total posts: 516
posted January 31, 2005 11:29 AM  
He changed the gauge already. How would the return line effect fuel pressure? all the pressure is measured on the othe side of the bypass right? Just asking.


Kromulous
Dirt Forum Champ
Total posts: 796
posted January 31, 2005 12:53 PM  
Smaller return line less flow out of the fuel log back to the tank, equals more pressure in the log.

Also you might go up on the supply side as well. That would do that same thing.

I say call BG and ask them what size lines you should be running on both.

Another idea, run the return line back into the supply line via a y split connector. I've seen guys do this and it works.

Question, is the gauge on the log or is the reading takin at the fuel log ?

waltonjr1
Dirt Forum Champ
Total posts: 516
posted January 31, 2005 04:53 PM  
I will give him a call tonight, I dont remember exactly how he has it set up, maybe he figured it out since he has not been back on here. I run streetstock so I dont have the alky fuel set ups down pack yet but I understand how it works. The way im thinking is that the bypass will regulate the pressure no matter what size the return line is, guess I could be wrong though.


Rat Trap
Dirt Maniac

Total posts: 129
posted January 31, 2005 09:54 PM  
What Kromulous was saying about running the return line to a y. Speedway makes a filter that has extra line fittings on it. We have one of them and run our return line right to it. Less line since you don't have to go all the way back to the tank, worked fine all last year.
We did have a fuel pressure problem early on, but it turned out to be a bad regulator. It was brand new straight out of the box bad.
sorry for all the edits. I tried to put a link to it on here and it wouldn't work for some reason..anyhow its on speedways website pretty easy to find if your interested
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racedad21
Dirt Newbie

Total posts: 2
posted February 01, 2005 07:03 AM  
Thank's for all of the reply's everyone. I got it fixed last night it was a piece of rubber in the fuel line between the gauge outlet and the carb outlet that was blocking the flow to the gauge. Some times the smallest thing's give's you the biggest headache. Well now I have a new spare fuel pressure gauge LOL.

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Kromulous
Dirt Forum Champ
Total posts: 796
posted February 01, 2005 07:24 AM  
I bet that was fun figuring that out, and finding that rubber bit in the line, yikes the headaches...

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