Just replaced fuel pump in the front tank on my 1990 f-150 with a 5.8L and upon starting I have to continue giving it gas to keep it running. It runs very sluggish. What could be causing this?

Asked by Aug 18, 2014 at 08:29 PM about the 1990 Ford F-150 XLT Lariat LB

Question type: Maintenance & Repair

9 Answers


How is it running on the back tank?

Best Answer Mark helpful

That pump will be changed soon. Hasn't worked in a while.

I'm thinking Maybe the TPS, checking injectors, and MAP sensor. Any ideas will be appreciated. I've already changed the plugs, wires, distributor cap, rotor, gas filter, canister purge sensor, new vacuum lines, and fuel pump (front tank). Changing the rear tank fuel pump tomorrow.


Have you checked for a electric problems to the pumps? It just seems odd that you have problems with both. Did try cleaning the pumps connections? I hate to see you spend money that you don't have to.

Yes, I changed the front tank fuel pump because I unhooked the fuel line at the engine and had low pressure. The back tank has not been used since 2000 and I figured they both are around 25 years old. The vehicle has been sitting for about a year and a half. I was driving it a couple times a week and noticed I had transmission fluid in the radiator so I installed a new radiator and just trying to get it back up to par. Spent about 10-12 thousand refurbishing it in 2000. It was my late Father's.


Go for it Gary. I have a Mercedes 450SL back in the states that my late father gave me and Im in the process of finding out what it would take to get it shipped here to the Philippine. It is special to me as your dads F150 is to you. I know the feeling to sit behind the same steering wheel that my dad did. There isn't a price anyone can put on it. Btw if you get parts from Advanced Auto Parts you can get some deep discounts if you purchase them online. Google Advanced Auto Parts coupons. I've saved a ton when I was back in the the states.

Which branch? ie. Army, Navy, Air Force. I was in the Navy and got back from the Gulf War on April 3,1991 and Dad had a heart attack the day after I got home and died 10 days later on April 14, 1991 at 55. I turned 23 a week later and had to get a Honorable Hardship Discharge to run Dad's business which he left my 3 year younger brother and I. Thought losing him would be the hardest thing I would ever face but in 2005 I lost my wife of 9 years (Cancer) only 3 months after she gave birth to our First and only child. We found out she had stage 4 and 8 days after being diagnosed she was gone. Her and I had spent the money on the Truck, therefore it means even more now and I plan to leave it to my Son at my death. Hope you have a blessed day or is that night?


First. Thank you for your service. Next. My deepest sympathy and condolences. One shining light is the Good Lord blessed you with a child. A son I assume, who will carry on with the preservation of the F150. I retired here in the Philippines officially this past January. My wife and I are raising our 3 year old son. He's my only child and he has a sister on the way. The usd gos a long way here and the locals like Americans. Should you ever find yourself in this neck of the woods we live on the island of Bohol in the town of Clarin. About an hour from Cebu by fast ferry.

Thanks for the follow up and yes God and Michele blessed me with a son. Congrats on the 3 yr old son and the soon to be new addition to your Family. My email is garypaul95@yahoo.com if you would like to communicate further. P.s. I myself will soon find out if I will have a new addition to our Family. P.S.s. I found the culprit to my Father's truck problem when I removed the upper manifold plenum. A rat had chewed the wire into on the 2nd from rear passenger side fuel injector and I am also changing the valve cover gaskets since I don't want or need (hopefully) to remove the plenum again. I hope and pray that your daughter comes healthy and full of love. Have enjoyed the comm's. Have a blessed day. Gary

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