2002 Chevy 454 Misfiring Losing Power

[Dennis Gaul]

A bit of history ...

Purchased MH July, 2017, 72,900 miles

Sep, 2018, after experiencing extreme loss of power, replaced plugs and wires, which restored very good performance (75,000 miles)

Dec, 2019, experienced loss of power, completed trip in 2nd gear at 40 mph; diagnosed as faulty fuel pump, replaced, restoring power (77,958 miles).

And now, the latest ...

After replacing the fuel pump, the engine ran very smoothly until I had traveled approximately 250 miles. I then hit a very rough short section of highway that I would describe as jarring. Almost immediately the engine started missing and losing power. I completed my trip (70 miles) in 2nd gear.

I took the MH to a service center. After confirming good fuel pressure out of the new fuel pump, replacing the fuel filter, and road-testing, the service manager was of the opinion that debris had passed from the fuel tank through the system and is interfering with the performance of the injector(s).
He offered the options of (1) spending the money to explore and identify the cause of the problem, or (2) continue on my trip and give the system a chance to clear itself. I chose option 2. While the engine runs well enough to travel, it still misfires and lacks power.

So now I'm looking for advice on how to proceed, hopefully avoiding costly guesses to solve the problem. I don't have the experience to do much myself.

[twinboat]

You could have debris in the gas tank that's drifting to the fuel pickup sock, dropping fuel pressures while driving.

[Geo19Irv]

You could have water in fuel tank

[n2zon]

Throttle body injection (TBI)? If so, could be the fuel pressure regulator, which IIRC is installed in the TBI body. Loss of power, backfiring, etc. If you get a replacement, make sure it's the high-pressure version. The low-pressure one will fit but won't deliver enough fuel. Don't ask how I know.


Also, they are rebuildable, if you can find a shop that does that.