1984 mustang 5.0 EFi wil occasionally sputter act like it's not getting fuel or firing

Terry Spradley

Asked by Sep 08, 2015 at 09:13 PM about the 1984 Ford Mustang GT Convertible

Question type: Maintenance & Repair

First noticed on longer trips, 1 hr, (and after running a can of seafoam through tank) While driving RPMs will drop like it's not getting fuel. Sometimes can last for a mile or two at 60, then straighten out and run fine for another 50 miles. Tried the old clothespin on the fuel lines trick. Seemed to make it less severe happens more often, but doesn't last as long. Also idles at about 1100 rpm, occasionally idle will fluctuate 300-400 rpms while idling the clear up and be fine. Car has been in storage, less than 2000 miles in the last 7 years. Have replaced the fuel filter. I think this is a two filter system. Saw what appears to be electric pump near filter while changing it.  Is this a fuel problem or electrical?  car has 167,000 miles

3 Answers

Terry Spradley

That should say a "two pump system"

Tom Demyan

Since the car was in storage, was the fuel drained and replaced? Carb rebuilt yet? Cars don't like sitting around. Check your normal things like plugs and wires, cap and rotor and vacuum lines as well.

1 out of 1 people think this is helpful.

Sounds like you may have the same issue that the older Cabriolets had. The fuel pump strainer in the tank picks up rust and it plugs it up. After you shut the car off, the rust will fall off the screen. Then after driving it for a while, the strainer will become plugged again and the car will begin to stall or feel like it's running out of gas.

1 out of 1 people think this is helpful.

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