Fuel system short

Tiny
BIGGS
  • MEMBER
  • 1993 BUICK ROADMASTER
  • 5.7L
  • V8
  • AUTOMATIC
  • 225,000 MILES
My 1993 5.7 buick roadmaster wagon has been stalling, sometimes it would start right back up and other times it would have to sit for anywhere between 5 to 90 minuets when it refuses to start the gas gauge would bounce around, I have replaced distributor brand new complete, idle air flow motor as it also had an idle problem which fixed that problem, replaced fuel filter and the next day it stalled once after about 3 miles and started right back up drove about 10 miles to work it sat there for 10 hours started right up drove it about 2-3 miles it stalled again and would not start but this time gas gauge is buried on full, please help me, what do I need to check and how do I test it? Im assuming its shorted out somewhere? Thank you
Wednesday, March 22nd, 2017 AT 9:26 PM

4 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
I doubt it's shorted check fuel pressure with a gauge auto parts rent it it should be 41-47 psi with 41 being minimum. It sounds like pump is shot. Also the short may be at the wiring going to sender as normally a grounded wire will make gauge go to full. It can also be the sender which if you have to replace pump just get the whole assembly. See pic on how to diagnose for a sender.
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Thursday, March 23rd, 2017 AT 5:56 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,314 POSTS
Try this test, Jack the car up enough that you can get to the gas tank. Use a rubber mallet or block of wood or even a solid fist to give the tank itself a few solid whacks. Sometimes that can be enough to move the pump and start it turning again.
If it does start turning again DON'T drive it until you can replace it.
The likelihood of it acting up is directly proportional to your luck. With me that would mean the pump would stop the instant I pulled out in front of a loaded semi.
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Thursday, March 23rd, 2017 AT 3:04 PM
Tiny
BIGGS
  • MEMBER
  • 16 POSTS
Thanks I will have to go through the process, steve that sounds easy enough sounds like your luck is about the same as mine lately I thank you for the info guys
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Thursday, March 23rd, 2017 AT 8:48 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,820 POSTS
Please use 2CarPros anytime, we are here to help and tell a friend.

Best, Ken
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Monday, March 27th, 2017 AT 4:23 PM

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