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Old 08-03-2007, 05:19 PM   #1
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Default Need help with no fuel pressure problem

I need some ideas chasing down a fuel pressure problem in my stadium truck. Here are the symptoms:

With the fuel line removed from the carb:
1. When I remove the fuel tube from the pipe and blow, fuel comes out

2. When I hold my finger over the stinger and push down onto the bump box, the fuel will come out

When I have everything hooked up as if I was going to hit the track, the fuel won't flow.

I checked my fuel tank and didn't find any leaks. My opinion is the pipe is not pressurizing properly and I can't figure it out. It is the Drake pipe where you push the fuel tube into the hole. I have tried different length pressure lines but no luck. I also checked the silicone coupler and it is tight and not cracked. Does anyone have any suggestions?
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Old 08-03-2007, 06:02 PM   #2
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I am having the exact same issue with my savage X, and i mean the exact same problem. Once i blow on the pressure line and get fuel in the carb it runs and runs great. I just cant get fuel into the the carb when i prime it with the pipe.
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Old 08-03-2007, 07:28 PM   #3
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Da same thing happens to my friends Savage too.
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Old 08-03-2007, 07:44 PM   #4
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Quote:
Originally Posted by pumpkinfish View Post

2. When I hold my finger over the stinger and push down onto the bump box, the fuel will come out

When I have everything hooked up as if I was going to hit the track, the fuel won't flow.
Not sure what exactly the difference is between these two? When you hold your finger over the stinger isn't everything hooked up just like you would go to the track? Easiest way to prime is doing just what you described. I like to kink the pressure line off with my thumb, then flip the lid up and down to prime my engine. That way you can see the fuel slowly go up the line. Works best if the throttle is a little open.

Anyhow, anytime I have ever had a problem where it didn't seem to want to draw fuel thru the line I just replaced the tank and that was that. What truck do you have?
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Old 08-04-2007, 02:17 AM   #5
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Default prime

If your idle is set to low it will not let fuel in when you prime it. Try holding the throttle open a little then put your finger over the stinger.
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Old 08-04-2007, 03:33 AM   #6
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If you don't have an obvious leak somewhere, check the pickup in the tank and the tank seal.
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Old 08-04-2007, 04:34 AM   #7
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check your feul lid to see if it is holding down and not releasing the presure under full power and put a feul filter on your pipe return line to regulate the presure in the line
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Old 08-04-2007, 05:36 AM   #8
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Quote:
Originally Posted by jbrow1 View Post
Not sure what exactly the difference is between these two? When you hold your finger over the stinger isn't everything hooked up just like you would go to the track? Easiest way to prime is doing just what you described. I like to kink the pressure line off with my thumb, then flip the lid up and down to prime my engine. That way you can see the fuel slowly go up the line. Works best if the throttle is a little open.

Anyhow, anytime I have ever had a problem where it didn't seem to want to draw fuel thru the line I just replaced the tank and that was that. What truck do you have?
What I meant was I was first doing these tests with the fuel line removed from the carb. The second sentence you quoted was meant to be read that I then hooked the fuel line to the carb. Sorry if it was not clear.

We did try cracking the throttle or even wide open and nothing was working. I will try taking off the carb and making sure it is clean then sealing it. The back plate is sealed already.

The truck in question is my old Mugen MST-1 stadium truck. I have a friend who wanted to run 1/10 truck for a race or two but didn't want to buy one. I have a GT2 to run personally, so I am just trying to help the local class by lending out my old truck. I will try a spare GT2 tank to see if that is the issue. If it works, I will have to fab up a mounting solution. I do remember putting in a new tank when I last ran the truck. That is why I never considered the tank to be an issue.
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Old 08-04-2007, 07:35 AM   #9
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If the engine has sat for awhile could be the fuel nipple is plugged. I just tried starting a nova that sat for a year or better and it did exactly what you described. Ended up the high speed needle assembly was plugged up with old fuel.
Hope ya get it figured out and your buddy like the class!!
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Old 08-04-2007, 08:48 AM   #10
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maybe the seal for the opening of the gas tank is craked
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Old 08-04-2007, 01:10 PM   #11
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I found the problem with my X SS, last time i took it to the skate park i landed it square on the roof which cause me to have a fuel line split. I promptly fixed that but upon closer examination, i found that when i hit, it deflected my shock tower down enough into my fuel tank and broke it. No massive cracks but under pressure the cracks do seep fuel out of them.
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Old 08-04-2007, 05:58 PM   #12
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Quote:
Originally Posted by fhm555 View Post
If you don't have an obvious leak somewhere, check the pickup in the tank and the tank seal.
He is very right on this one. Check to see if the pic-ups or fittings on the tank are loose or stripped. Also check to see if your carb is not flush to the mount or loose. Tighten everything from the carb base, banjo fitting, HS needle all the way to the tank.
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Old 08-05-2007, 09:44 AM   #13
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Also make sure you check your header/pipe coupler. I had one split and it also caused the same issue. Make sure you check the underside and backside of it.
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