My truck flooded out (too much gas) and shut off?

CHRISW629

MEMBER
1987 NISSAN TRUCK
4 CYL
2WD
MANUAL
385,000 MILES

About two weeks ago my truck flooded out (too much gas) and shut off. I waited a few minutes and restarted it.I had the same problem a week ago and now it won't stay running at idle, I can keep it running with the accelerator, but it popps and backfires. I have tested both coils, and coil control modules, I have also replaced the throttle position sensor after checking the cpu for codes, the cpu had codes for throttle position sensor malfunction and coolant temp sensor circuit failure.

please help

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

If the engine gets excessive oil, it will not stay running and will backfire due to unburnt fuel.

This issue could be due to a faulty fuel pressure regulator. The job of the fuel pressure regulator is to control the fuel flow and volume at a predetermined amount that was calibrated for the specific engine. A faulty regulator can allow too little or too much fuel and cause the engine to flood. Which will lead to poor idle or engine shutdown.

One of the ways this can be tested by checking the fuel pressure.

Here is a helpful guide on how to test the fuel pressure:

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

I have attached diagrams below for your reference.

Please let me know if you have any questions.
Thank you.

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