Is it the Fuel Filter, Fuel Pump or Wiring?

Asked by Mar 08, 2014 at 06:43 PM about the Ford Thunderbird

Question type: Maintenance & Repair

My 1992 T-Bird, was doing really good until I got it smog, had an o2 sensor replace and an egr sensor. Went to a Valero gas station then it started running horribly, jerking, missing, I burned out the Valero gas and put in my regular 76 reg. gas... it ran okay for a while then again Valero, now my car is went from bad to worse... I have to pump the gas to make it work.. I read your other answers, but how to know for if it's the fuel filter, fuel pump or wiring?  And where are these located without the manuals , can you just answer please..  er.. thanks  lady Tbird

9 Answers


It only runs poorly on the Valero gas? If so I would not use it if possible. I have two older cars that only run properly on chevron gas. If I buy any other type of gas the performance drops considerably at times to the point where they miss and have hard to start issues.

2 of 2 people found this helpful.

Why would even go back if you had a problem not that long ago, you need to siphon out as much of the fuel you can get, put in a least 5 gallons of good fuel, add some octane 104 to the 5 gallons, change the fuel filter, it is located on the frame rail either close to the tank on the drivers side, it will be concealed buy red plastic cover held on by 2 8MM bolts and 2 plastic clips that will be supplied with a new filter, make sure they are in the box, after fuel filter is replaced turn the key on for 3 seconds then off for 8 seconds, do this a least 3 times, this will help flush the bad fuel out of the lines and be diluted by the good fuel in the tank, during this operation you should be able to hear the fuel pump run then stop, this is normal, then try to start the engine if it fires and runs it might be a little rough for a while until the bad fuel is purged, then fill tank with good fuel.

2 of 2 people found this helpful.
Best Answer Mark helpful

Chances are its not Valero gas...its the gas from that Valero station. Bad gas is nearly always traced to bad gas stations or tanker trucks more than the refineries. Water and contaminates make it into tanker trucks and underground tanks from cracks, bad seals and access points being left open. I have used Valero gas a few times while traveling and never had an issue. On the other hand, I used Speedway nearly exclusively for nearly 8 years without an incident...but the only "bad gas" I ever had was from a Speedway where filling up an empty tank got me 21 gallons of gas and 3 gallons of thick brown slop that would separate and settle under the gas. Consider gas stations the same as mechanics...find the ones you can trust and give them your regular business to they can stay in business.

2 of 2 people found this helpful.

Comment: Changed the egr sensor, without also changing the egr valve???

1 of 1 people found this helpful.

Fuel filter is on the pessenger side under the plate. Wires are under the rear seat, fuel pump relay is in the trunk on the driver side so is the fuel pump shut off switch behind the carpet. Do you hear the fuel pump come on at all?

2 of 2 people found this helpful.

Is that what the that fan noise is? I'm not sure.. on the passenger side under what plate? I thought is was alongside the tubing fuel metal hose?

This Valero gas station had all pumps closed except one opened, I thought that too was strange, but because I was on E I had no choice. Will running the car on E damage the fuel pump? Appreciate all the valid answers... the EGR sensor was replaced, but not the EGR valve didn't know I needed the valve, keep in mind the sensors were replaced to pass the smog and now I'm have problems.

You should hear a noise when you turn the key to the on position(all lights on the dash is on) If you don't hear any thing then the pump is not working. With that said on my 93 with a 5.0L the wire was twisted to gether from previous owner leading to the fuel pump.

1 of 1 people found this helpful.

Running a car out of gas will damage the fuel pump.

1 of 1 people found this helpful.

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