need advice on fuel pmp
Thread Starter
Racer
Joined: May 2014
Posts: 416
Likes: 29
From: diamond bar ca
need advice on fuel pmp
My fuel pressure s been bouncing around erratically meaning pressure will drop around hard corners and if i sway it back and fourth on around close to empty it will act like it wants to die, pressure guage was tapped to window and sometime s it will flucuat 5 to 10 lbs. so i started it up this morning and it just quit, put the guage on it , nothing the guage stays at zero. attach my dvm to the hot wire to the fuel pmp + - by the filler and turned the key on voltage went to around 12 volts for 2 seconds so i know its getting voltage, the question is should i replace just the pmp or the whole sending unit with the pmp.. thanks
Thread Starter
Racer
Joined: May 2014
Posts: 416
Likes: 29
From: diamond bar ca
thnks for the quick reply, im confused though what does the pulsator do and replacing with a short length of hose will do what. thanks
Race Director
Joined: Mar 2015
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If you have a pulsater they are no longer available and just use the proper hose. It was like a hammer valve like in house plumbing. And not needed. The hose will connect your pump to the fuel line. Without it you will just have a fountain inside your fuel tank.
Last edited by antfarmer2; May 16, 2016 at 07:30 PM.
Team Owner
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I believe that if a person wanted/or wants the "pulsator" they are still available. I believe the NOT AVAILABLE was mentioned here earlier and I don't believe it's so. There's a local here that if it's a customers car it goes back together with the "pulsator"/dampener every time. Unless customer specifies NO!! There's likely multiple brands available - I'd likely wager that.
Race Director
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I believe that if a person wanted/or wants the "pulsator" they are still available. I believe the NOT AVAILABLE was mentioned here earlier and I don't believe it's so. There's a local here that if it's a customers car it goes back together with the "pulsator"/dampener every time. Unless customer specifies NO!! There's likely multiple brands available - I'd likely wager that.
found it on zip $34.50 I will stick with the hose.
Last edited by antfarmer2; May 16, 2016 at 07:47 PM.
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
C4's are some what notorious for fuel starvation on hard cornering when the fuel level is down to about 1/4 full. My old '87 would have the same issues during autocross and track events even with the tank 1/3 full.
I try to never have less than a 1/3 of a tank. The fuel is also what keeps the pump cool. If you constantly let the fuel level go down to where the reserve indicator is on, you could burn up the pump.
I try to never have less than a 1/3 of a tank. The fuel is also what keeps the pump cool. If you constantly let the fuel level go down to where the reserve indicator is on, you could burn up the pump.
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Race Director
Joined: Apr 2002
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From: Anaheim CA
I don't believe that would happen. When the pump runs out of fuel so does the engine and it would stop running.
Thread Starter
Racer
Joined: May 2014
Posts: 416
Likes: 29
From: diamond bar ca
Replaced the fuel pump motor and is now running, thanks all for the advice. Have some other running problems but will start another thread on that one. thanks again for all the great help...
Team Owner
Joined: Jul 2004
Posts: 28,474
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From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
C4's are some what notorious for fuel starvation on hard cornering when the fuel level is down to about 1/4 full. My old '87 would have the same issues during autocross and track events even with the tank 1/3 full.
I try to never have less than a 1/3 of a tank. The fuel is also what keeps the pump cool. If you constantly let the fuel level go down to where the reserve indicator is on, you could burn up the pump.
I try to never have less than a 1/3 of a tank. The fuel is also what keeps the pump cool. If you constantly let the fuel level go down to where the reserve indicator is on, you could burn up the pump.
Absolutely FALSE. If you believe that can happen, I have a stock tip for you. Buy Walbro stock. I have run EVERY CAR that I own down to the bottom and the only replacement pump I installed is because I was transplanting the 383 and wanted to be sure there was enough fuel. Just an old wives tale circulated again and again. Don't believe me? Ask Tom400CFI or watch his video HERE. Temp doesn't break 100 even when forced to run without any fuel and pump probably will go on for much longer. Wish Tom would run it till the pump burns up so we know.
Ask yourself this. Assuming you run out of gas, what exactly do you think the happens to the power to the pump? Hint: Engine stops
Team Owner
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From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,474
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From: Hartford WI
If not, I suggest you get THIS. I don't know what year you have but they have an install kit for it. The pulsator never has to be a problem since you will be replacing it with a FUEL RATED HOSE instead of some other hose that probably will be dissolved by the fuel
Thread Starter
Racer
Joined: May 2014
Posts: 416
Likes: 29
From: diamond bar ca
fuel pump
If not, I suggest you get THIS. I don't know what year you have but they have an install kit for it. The pulsator never has to be a problem since you will be replacing it with a FUEL RATED HOSE instead of some other hose that probably will be dissolved by the fuel
Thread Starter
Racer
Joined: May 2014
Posts: 416
Likes: 29
From: diamond bar ca
Team Owner
Joined: Jul 2004
Posts: 28,474
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From: Hartford WI
I replaced with a new sock, but what kind of problems can a pulsator cause?. Prior to replacing fpm i had close to 40 lbs fuel pressure but it would not hold pressure and would leak down,, new pump motor same pressure and still will not hold pressure. regulator is new and it does not seem to be leaking via the injectors ,,,they have been replace with Bosch from fic. i can live with it and it does not seem to effect the performance...
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From: Anaheim CA
Team Owner
Joined: Jul 2004
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From: Hartford WI