High fuel consumption after relacing fuel injection and catalytic converter?

1992 TOYOTA COROLLA
200,000 MILES • 4 CYL • 2WD • MANUAL
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CARHEADACHE2020
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I recently had a new catalytic converter installed, as well as a new fuel injection pressure regulator installed, but the car is going through more fuel than it should.

Any idea as to where else I should look?
Jul 28, 2022 at 2:13 PM
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JACOBANDNICKOLAS
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Hi,


If you are using excessive fuel, it could be a few things. First, is the air filter clean? Also, have you checked for any engine vacuum leaks that may cause the computer to add fuel to the engine?

Also, I want you to try something. Here is a link that explains how to retrieve codes. This vehicle has an OBD1 system which doesn't require a scan tool to get codes. Follow the directions in this link and let me know if there are any codes stored:

https://www.2carpros.com/articles/toyota-trouble-code-definitions-and-code-gathering-method-1990-1995

Also, the fuel pressure regulator is dependent on the engine vacuum to function. It is located on the fuel rail. See pic below. Confirm the vacuum hose to the regulator is connected and not damaged. With the engine running, you should feel a constant vacuum at the end of the hose, so confirm that as well.

Let me know what you find.

Take care,

Joe

See pic below.
Jul 28, 2022 at 2:46 PM
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CARHEADACHE2020
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Hello,

Thanks for your response. The air filter is clean and there are no vacuum leaks. I have an OBD1 scanner, and for some reason I cannot pull a code because there is no pause between the flashing lights. The flashing is consistent. Where do I go from here? Very frustrating.
Jul 30, 2022 at 5:44 AM
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JACOBANDNICKOLAS
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Did you try just jumping connectors at the DLC?

Let me know.

Joe
Jul 30, 2022 at 7:43 PM
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CARHEADACHE2020
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Same thing happens when I jump connectors. Steady flashing.
Aug 2, 2022 at 5:58 AM
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JACOBANDNICKOLAS
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Hi,

If it flashes steadily when you jump the connector, there are no codes stored. Were you able to check fuel pressure? Here is a link that explains in general how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know.

Joe
Aug 2, 2022 at 12:57 PM
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CARHEADACHE2020
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Hi, I am finally getting back to working on the car. The fuel pump is okay. What should I look at next?
Oct 15, 2022 at 7:54 AM
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JACOBANDNICKOLAS
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Hi,

If the fuel pressure is within the manufacturer's specifications, the air filter is clean, and the engine is running properly, this is a tough one.

By any chance do you have any exhaust leaks before the catalytic converter? For example, do you notice any noise at the exhaust manifold?

Let me know.

Joe
Oct 15, 2022 at 9:34 PM