Author Topic: Do i need to replace my fuel pump  (Read 2526 times)

Offline TelisSE440

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Do i need to replace my fuel pump
« on: August 03, 2015 - 04:49:06 PM »
I haven't started my Challenger for 3 months... When i got home this afternoon, tried to start it but saw no fuel in the bowls. Since the fuel gauge was almost to the bottom, i suspected no gas and filled her up. When i cranked the engine, i saw no fuel bowl filling and the fuel pressure gauge i had installed showed no movement at all. I removed the rubber line from the filter to the carburetor and cranking the engine showed what seemed to me too little fuel too slow. I guess the fuel pump is the culprit or should i search more? Thanks anyway guys...




Offline burdar

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Re: Do i need to replace my fuel pump
« Reply #1 on: August 03, 2015 - 04:55:27 PM »
I'd fill the carb to pump line with fuel.  You can also fill the carb bowl through the vent.  Sometimes the fuel pumps will lose their prime.  If you can get the engine running, you have a better chance of getting the pump to pick up fuel.  I'd try that before buying a new pump.

Offline brads70

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Re: Do i need to replace my fuel pump
« Reply #2 on: August 03, 2015 - 08:34:38 PM »
If you pull off the pump check to see if the pushrod has worn too short, then not cycling the pump.
Brad
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Offline jhaag

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Re: Do i need to replace my fuel pump
« Reply #3 on: August 03, 2015 - 10:50:03 PM »
If it ran ok 3 months ago it should still be ok, unless the diaphragm failed. fill the float bowls as Burdar said, start it up, and see if it will regain it's prime.
love 70 Challengers

Offline Chryco Psycho

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Re: Do i need to replace my fuel pump
« Reply #4 on: August 03, 2015 - 11:17:25 PM »
it should be moving a good amount of fuel if the line is open , my duster / 440 used 1/2 in 11 seconds at the track , you need to have around 1/2 qt in 15 seconds minimum.

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Offline TelisSE440

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Re: Do i need to replace my fuel pump
« Reply #5 on: August 04, 2015 - 02:33:42 PM »
Thanks guys for all the inputs  :thumbsup:, i filled up the fuel bowls and when it started, it picked up the normal pressure, i traveled it about 40 miles and everything was ok. I also checked the amount of fuel passing, it moved a little lower than half a liter in 15 seconds (liter is almost equal as a quart, 1 to 1.05 i think). I have another two new fuel pumps when i bought the car (!), so i will sure check the pushrod if the pump finally fails and have to change it, i didn't know something like that existed until now...

Offline dfrazz

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Re: Do i need to replace my fuel pump
« Reply #6 on: August 04, 2015 - 02:42:39 PM »
Even if the pushrod is 1/8" short, it will dramatically effect the amount of fuel since it is at the end of the pump that most fuel is moved.  I replaced mine and it made a difference.


Offline chaps70rt

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Re: Do i need to replace my fuel pump
« Reply #7 on: October 18, 2015 - 12:38:28 PM »
I agree .... there is a hardened end on the rod.   When it starts to wear, the engine is starved of fuel.  My '67HP 440 had this issue, it went  un-diagnosed and the engine was pulled from the original car and sat on a stand for years.   Once I received the motor, it was determined that the push rod was worn.    We replaced it, now the engine runs strong.
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Offline anlauto

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Re: Do i need to replace my fuel pump
« Reply #8 on: October 18, 2015 - 12:59:41 PM »
It's happened to a lot of 440's I've had too... :pullinghair:
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Offline cudabob496

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Re: Do i need to replace my fuel pump
« Reply #9 on: October 18, 2015 - 05:07:42 PM »
Just replaced my pushrod. Had it in there for 15 years. Only shortened about 5/100 of an inch.
But I use synthetic oil.
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