Rough idle after road trip

[tmoreau]

This is a long post because I want to supply all the info, I am seeing a pattern here and want to nail the problem this time if I can.

I bought my truck new in Oct.01 and now have just under 25k miles on it. I took a 4500 mile road trip from chicago to san diego once, and often drive from chicago to northern wisconsin. The rest of the miles are around town in the chicago area. Here is the scenario, I washed the engine once and got water in the distributor cap (d'oh) and didnt realize that was what happened so I brought it to the dealer.

 

3-15-02 10204 miles

Scan data DTC 0300 road tested clear injectors #4 misfire flush injector system #4 still missing test availible spark at #4 test wire remove cap and rotor contaminated replaced cap and rotor recheck all ok

 

I had noticed before that my acceleration was not smooth, the power was choppy for lack of a better term. I noticed this mostly in second gear but it wasnt really pronounced enough to think much of it. Anyway, when I got the truck back I noticed that it ran a lot better and I didnt realize how bad it was before. Several months later I brought it in for the steering shaft clunk and told them that it was again running a bit rough. Additionally, in the mornings the first time I would take off from a start the engine would hesitate, felt like it would die if I didnt stomp on the clutch. Only happened after the truck sat all night.

 

11-7-02 18956 miles

Inspected and checked for codes, found P0300 code stored, random misfire, recomended bulletin#(00-06-04-003A). Flushed fuel injectors per bulletin, reset codes, testdrove-ok.

 

Again it ran much better. I replaced the fuel filter on 11-17-02 with 19790 miles.

 

3-18-03 24700 miles

I just returned from wisconsin again and it is idling rough and the acceleration is just not right. This morning when I started it I turned the key on and the fuel pump make a noise like it was sucking air for a couple seconds. Usually I just hear a buzz/humm from the fuel pump (before starting engine). It seems like I usually notice problems after I come back from a road trip, and I am wondering if the differences in gas formulas in various regions could be causing some of my grief? Does anyone have any sugestions on what I should say when I bring it to the dealer this time? It seems that they clean the injectors and the truck runs better, if thats true then why are the injectors fouling like this? If thats not exactly how its happening then what are they doing to cause an improvement?

 

Thanks, and sorry for the long post.