High fuel consumption after relacing fuel injection and catalytic converter?

Tiny
CARHEADACHE2020
  • MEMBER
  • 1992 TOYOTA COROLLA
  • 4 CYL
  • 2WD
  • MANUAL
  • 200,000 MILES
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?
Thursday, July 28th, 2022 AT 2:13 PM

7 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
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.
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Thursday, July 28th, 2022 AT 2:46 PM
Tiny
CARHEADACHE2020
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  • 10 POSTS
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.
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Saturday, July 30th, 2022 AT 5:44 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Did you try just jumping connectors at the DLC?

Let me know.

Joe
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Saturday, July 30th, 2022 AT 7:43 PM
Tiny
CARHEADACHE2020
  • MEMBER
  • 10 POSTS
Same thing happens when I jump connectors. Steady flashing.
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Tuesday, August 2nd, 2022 AT 5:58 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
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
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Tuesday, August 2nd, 2022 AT 12:57 PM
Tiny
CARHEADACHE2020
  • MEMBER
  • 10 POSTS
Hi, I am finally getting back to working on the car. The fuel pump is okay. What should I look at next?
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Saturday, October 15th, 2022 AT 7:54 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
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
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Saturday, October 15th, 2022 AT 9:34 PM

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