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Installed new fuel pump, but car still feels "off"...any thoughts?

Hi, I had a new fuel pump installed on my 1997 Honda Civic (145K miles) last week after it started hesitating and bucking one day and then the Check Engine light came on. I picked the car up last Thursday, and it runs and starts, but I still feel “something off”…it seems to have small surges of power/lack of power while I drive. Again, always starts and runs but it just doesn’t feel right. I am not super car savvy and would like to return to the mechanic tomorrow with a little bit more knowledge about what may be going on. I spent quite a lot of money on the repair and wonder if they know what they’re doing; any advice would be greatly appreciated. Thank you

It could be many things but here’s a start:

That vintage honda has been known to have issues with the main relay. It basically provides power to the fuel pump and the part has a tendency to have intermittent problems.
It often affects starting but can also affect driving. Here’s a link on the part.
http://www.tegger.com/hondafaq/startproblems.html#mainrelay
The part can often actually be fixed inexpensively by resoldering connections.

Has your mechanic checked the fuel pressure? That could also be a cause for what you are describing.
No doubt he’s changed the fuel filter. A clogged filter could definitely do what you describe.

The fuel pump provides a constant fuel pressure to the fuel injectors. It’s the job of the fuel pressure regulator to control the fuel pressure to the fuel injectors. Have them check for a leaking/malfunctioning fuel pressure regulator.

Tester

thank you-so the fuel pressure regulator is a different matter than the actual fuel pump? wouldn’t they have made sure “everything” was working in sync? Or did putting in a new fuel pump just address part of the issue?

Usually when one replaces a fuel pump, you check to make sure the pressure is correct because those things vary in pressure. That’s inherent of the part but there’s a fuel pressure regulator in the FI system that makes sure that the injectors get the right pressure - that’s the part he may may need to look at.

Yep! The fuel pump is mounted in the gas tank. The fuel pressure regulator is mounted on the fuel rail on the engine.

Tester

thank you for your advice-much appreciated