Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

99 camry fuel pump (again)

I finally took out the seat and started the car, when car running I can clearly hear the pump whirring in the tank. As soon as I unplugged the wire the engine shut off. Does it mean the pump is weak? I took out the whole pump assembly, what should I do next? Replace the pump with the strainer? I can’t name one part that kind of looks like a filter with cardboard type of thing inside, is that the inlet? Where can I find an exploded view of a fuel pump? Thank you again.

I don’t know what you are doing. I don’t know what the problem is with the engine performance.
On your prior post, you said that you disconnected the fuel line at the fuel filter and no fuel came out. Now, you say you disconnected some wire and the engine shut off. What is going on?
If there were no fuel coming through the fuel filter, the engine wouldn’t run; yet, you disconnected a wire (somewhere), and the engine stopped running! The dots do not connect.
There is a filter attached to the fuel pump. It looks like a sock. That’s why, it often is called a sock.
Go to this site, register, and click on this link again. Enlarge the figure of the fuel pump and it will show the names of the parts of the fuel pump.

The idle at times is rough and acceleration sometimes sluggish. I’m not exactly sure what’s the problem, first I changed spark plugs and wires and then fuel filter. When I was changing fuel filter with inline disconnected I had my wife turn the ignition on till dash light came on, I was expecting fuel squirting out of the tube but nothing came out. So then went to pump today, I disconnected the fuel pump wire that’s under that back seat and engine died right away. The reason I thought it might be weak pump is that:

  1. When I took off the fuel filter the lines weren’t under pressure.
  2. When I disconnected fuel pump wire the engine died right away.
    I’m guessing it’s a weak pump and sending just enough fuel for the engine to run ok sometimes and other times not being able to send enough fuel for it to run normally. Or could it be fuel injectors? When I changed spark plugs the old spark plugs were dry with very little gray build-up on them. It wasn’t changed since 2004. Thank you Hellokit for your input.

When the engine is shut off, the fuel pressure should remain in the fuel line for at least a 1/2 hour. If the static fuel pressure falls off, it can be because the fuel injectors are leaking the pressure off, or the fuel pressure regulator is bleeding the pressure off, or the fuel pump check valve is allowing the pressure to bleed off. These conditions DON’T mean a weak fuel pump.
Your problem is an intermittent rough engine performance. …Cause unknown.
The problem could be caused by fuel pressure which is erratic. This could be from erratic electrical power to the fuel pump, or it could be the fuel pump…it’s hard to tell the difference.
You can tell if the fuel pressure is low, or erratic, with a fuel pressure gauge. A fuel pressure test gauge is a lot cheaper than a fuel pump, I’m sure.
Another suspect is the Circuit Opening Relay (which powers the fuel pump). Swap that relay with another in the fuse/relay box under the hood. Use the fuel pressure test gauge and test drive the car. Results?

I know that you are trying very hard to avoid investing $60 or so in a fuel pressure gauge that you will probably never use again. And I’m sympathetic. But I don’t see much chance that you are going to resolve your problems without breaking down and buying one. An Acctron CP7838 or something similar should do the job.

Good Luck.