Not getting gas with new fuel pump

Tiny
JASON MAJOR2
  • MEMBER
  • 1986 MERCURY LYNX
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 88,000 MILES
I acquired this car free (taxes for title transfer only). The vehicle will start with starting fluid sprayed directly into the carburetor. With the air filter cover off I am able to keep the vehicle running by spraying starter fluid from side to side in the carburetor. Does not seem to be getting gas. I disconnected the fuel pump from filter and was able to determine it will pump while running (keeping car running with starter fluid) but will not pump fuel from cranking over.

Figuring it was a weak fuel pump, I put in a new fuel pump. However it is still doing the same thing. Any ideas?
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Tuesday, July 12th, 2016 AT 2:58 PM

5 Replies

Tiny
HMAC300
  • EXPERT
Check for a blocked line or a lot of stuff in tank blocking pick up of fuel. Hard telling how long it has sat and gas is probably bad in the tank.
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Tuesday, July 12th, 2016 AT 3:36 PM
Tiny
JASON MAJOR2
  • MEMBER
I know it sat for about eight months. The previous owner drove the car just around town until about eight months ago when they got a pickup out of the shop. I found a service invoice in the car dated 4/15/15 for the tire shop twenty miles away, and the son of the old guy met him for lunch about eight and half months ago in that car. Knowing the car had sat for just under nine months I added a half bottle of Heet to the fuel (1/4 tank) and then topped up the tank with fresh fuel. It really seems the main thing is it wont pump gas to the carburetor unless it is running. I will see what I can do to check out the fuel line and the pick up.
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Tuesday, July 12th, 2016 AT 5:50 PM
Tiny
CARADIODOC
  • EXPERT
Hi HMAC300. I cannot help but stick my nose in here again with two comments of wondrous value, then I will leave you guys alone. First of all, the fuel pump had better not be running unless the engine is running, and that is what you found. If it would run anytime the ignition switch is on, you would have a major fire hazard. If a fuel line gets ruptured in a crash, it will dump raw gas onto the ground. With no fuel pressure, the engine cannot run. With a stalled engine there wont be any signal from the crankshaft position sensor and / or camshaft position sensor. Missing those signals is what tells the Engine Computer to turn the fuel pump off. All you might hear is the hum of the fuel pump for one second after turning on the ignition switch. It wont turn back on until there is engine rotation, (cranking or running).

Second, only Chrysler has never needed a mass air flow sensor to make their engines run right. All other manufacturers use that sensor on almost all of their engines for the major fuel metering calculation. If any air sneaks into the engine that does not go through that sensor, it wont get included in the fuel calculation. You are spraying starting fluid into the throttle body, (which can be a valid test procedure), but you need to have the fresh air tube removed to do that. That means no air is going through your mass air flow sensor and the Engine Computer will match that with the appropriate amount of fuel, which is none.

Adding Heet is not going to do anything. Gasoline today has ethanol in it which is alcohol. If I remember right, Heet is isopropyl alcohol which is different, or some other kind of alcohol, but mold feeds on both of them. That mold can plug the pickup screen in the gas tank that HMAC300 is talking about. That said, I have a 1993 Dodge Dynasty with less than 5,000 miles that regularly sits for three or four years between running the engine, and the same with an 1980 Volare with 45,000 miles. One is fuel injected and one has a carburetor, but both have gas in them that is over five years old. They both run fine on that old gas, but that cannot be said about other blends in other parts of the country. Regardless, I would not be too concerned about nine-month-old gas.

There is my comments of value. Hope that gives you guys something to think about.
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Tuesday, July 12th, 2016 AT 9:10 PM
Tiny
JASON MAJOR2
  • MEMBER
Thank you Caradiodoc, that does give me some to think about. I do believe there are a couple things that could be wrong after thinking about the airflow. There is one port on the air filter housing that does not have a plug or a hose attached. And there is an air warmer hose between the block and the clean air intake that was damaged during the fuel pump swap.

Also this car has a mechanical pump so I have had no indicator of it is running or not. I am not really a car guy so I am not overly sure what I am dealing with.
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Tuesday, July 12th, 2016 AT 9:52 PM
Tiny
CARADIODOC
  • EXPERT
Oops. Sorry about that. I assumed this was fuel injection. Forget everything I listed about mass air flow sensors and cam and crank sensors.
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Tuesday, July 12th, 2016 AT 9:59 PM

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