Missing 454

[crownie202]

I have a 99 GMC crewcab OBS with a 7.4l. The problem is that at about 3,000 RPM

it starts to miss like it is not getting enough fuel and won't shift into third. I replaced the fuel filter, and had the codes read. But nothing shows up.

 

If anyone has any ideas I would like to hear them. The GM mechanic thinks it runs fine I don't agree.

[99-2door]

had a 96 with the 7.4L doing that. Turned out to be the cam position sensor.

It was almost right at 3000 RPM where it would do it.

[crownie202]

had a 96 with the 7.4L doing that.  Turned out to be the cam position sensor.

It was almost right at 3000 RPM where it would do it.

 

<{POST_SNAPBACK}>

 

 

 

It is not consistent with the missing. I would think that if it

was the sensor it would be more consistant. What about the fuel pump?

Do they slowly go out or just quit?