Stumble After Startup.......

[1993GMCSierra]

Hi all,

I replaced my fuel filter the other day, and since then have noticed a "problem".

When the truck is cold (and it seems, only when it's cold), I'll hit the key, and it'll fire right up, and then stumble for a second or two, almost like it's not getting enough fuel, or a couple plugs aren't firing.

After that, it runs smooth as silk, has plenty of get up and go, etc.

I don't think it's the pump, as it will boogie as soon as you press the gas down (most power it's had since I owned it), and I don't think it's the ignition system, as I just replaced the plugs and wires.

I guess it's possible it could be the cap and/or rotor, but I don't think it would do it just initially, then never again.

 

[firefighter_2319]

try unplugging the map sensor and see if it does it. sometimes that will cause the engine to run like its missing at times. if it dont do it after you unplug it then try it again plugged up. if it runs like it did before then i would have it tested