Hey guys. I just changed my fuel pump. Today my truck lurched back and forth whenever I let off the gas. Also there was a ticking noise coming from engine. I put $15 in the tank and it stopped. Any ideas?

 

Fuel injectors make a ticking noise, Fords(mazdas) are quite loud.

'99 4.0l would need 60psi fuel pressure at the injectors, less would cause computer to open them longer and could make them louder.

Also lower or varying pressure would make engine/computer struggle to try and keep air/fuel mix correct, so bucking, like you would get with dirty MAF sensor.

When you change the fuel pump you will get air in the system, no way around it, but it will come out at the injectors within a few minutes, this would cause stumbling engine and maybe injector noise.

But it would be purged after that.

If you didn't get fuel line connections tight or new fuel pump is not working right(very common now a days) then issues could continue.
The fact that adding more fuel changed engine operation would point me at new fuel pump issue.

 

Thx RonD. If it continues I will take the fuel pump back. I hope it is just air in the line. I'll check the maf sensor too.

 

If the truck did not have this problem before you replaced the pump...it could be a defective pump, what brand did you get....plus did you replace the filter, if not then thats your problem for sure.....it only takes a few seconds to clear air out of the pump/injectors

 

The pump is a Delphi. I changed the filter. This was a week ago. The problem hasn't come back since filling up this afternoon. I'm gonna keep a close eye on it.

 

You can often borrow/rent a fuel pressure gauge from auto parts stores, that would tell you instantly if fuel pressure/pump was the problem.

1999 Ranger/B4000 spec is 65-72psi engine running at idle.
And pressure should hold above 60 psi at 2,500rpm for 2 minutes.
Then engine off pressure should stay above 50psi for a few MONTHS, so not minutes or hours, months lol.