Flushed the coolant today, and had the RPMs up to circulate it and get some heat into it to open the t-stat. Once it started getting warmer, it started shaking the truck. Its not a consistant miss, pretty erratic. It seems to be worse around 1500-1600 RPM. Still there at 1900. Bring it to 2k, and it smooths right out. Its smooth going up through the RPMs, but try and hold it, and it gets rough. Even at 2k, when you let out of the throttle (even just a 50 RPM drop), it gives the truck a good shake. Its been this way for a while, but I never played with it sitting still, so I never knew the extent of it. Once it was warm, it would idle poorly since I had the IP an injectors put in. Actually, come to think of it, it was similar on the old sticks and IP. It drove fine except when it was around 1500 rpm in 2nd and 3rd, during rush hour.

One thought I had was seeing a thread here months ago about the ECT going bad and causing a surging at part throttle in the lower RPMs. Last I checked, I never had any codes (that mattered), but I'll take the smarty out tomorrow and check.

Thanks for any help.

 

I have had similar problems with my 01 for a long while. The miss has gotten worst with the added performance items and is getting worst with time. About a year ago I did get the truck to idle a little better by changing the compression washers on the bottom of the injectors. You may try that. I have changed every sensor on the engine including the ECT with no luck. (3 - injection pumps, 2 - lift pumps, 3 - sets of injectors, on and on and on)

Regards,
Gene007

 

I think I might try a set of different injectors to see if it clears it up. I could pull the Smarty off too, see if it changes, although it did it before I put that on. I'll be sure to take a look at the injector washers if I do yank them.

 

I tried out several different softwares on the Smarty, and other than changing the way it drives, it was the same. Although it did run rougher quicker on #9 than it did on #0. Must say, after a year driving on #7, #9 is quite a change.

Gonna try some clean stock injectors next week, we'll see what happens.