Engine miss

[natman]

I have a 95 T100 4x4 3.4 v6 5spd with 210000 miles. It has developed a miss when you step into the throttle. If you are easy on it (1/8 or less into the throttle) it runs just fine and you can accelerate slowly without it missing. But if you mash the gas down much more it begins to miss. Another thing that has me stumpped is that sometimes you can punch it to the floor and it will go ahead and take right off, like if you have been driving easy for a couple of miles. It will go strong without missing but after a few seconds it will begin to miss again. I have replaced the spark plugs, plug wires, fuel filter, and put 2 bottles of fuel injector cleaner in about half a tank of gas. I thought it might be the TPS so I tried unhooking it and all it did was add some hesitation when you step on the gas but it still has the same miss in it. Also, the check engine light is NOT on. Does anyone have any ideas as to what might be causing this to happen??

[sd1]

If the engine has a knock sensor that sounds a lot like the symptom of one going bad...also do a compression check to make sure your good there. Wish the check engine light would come on so you could get a code from it....really surprised it hasnt yet.

[suv]

Although it's not that easy to check, it could be clogged injectors. Each injector has a little screen filter on it. If you get some crud in the filter inside the injector (happened to my buddy's truck @ 180k), it won't matter how much cleaner you run through. Mechanic I talked to said using Heet can dislodge residue in the fuel lines and clog those filters in the injectors. It may not be a bad idea to have all the injectors cleaned and checked anyway, as it will probably improve your performance.

[board350]

Try check the wiring harness plugs into the ECM and everywell else for that matter. A little Honda car I worked on was doing similar things and it turned out to be corosion on the main plug. Cleaned it off and it ran better than ever. Sometimes they will open far enough to break the seal and let moister in and not to long after its over. Just a thought. Remember check the simple things first, it is alot easier and cheaper.