hey guys whats up, well ive done a ton of work on my truck lately, im having a problem with a miss at idle its more profound when its cold but seems to smooth out after driving for awhile ive replaced the egr position sensor, and the egr vacuum solenoid to no avail ive checked for vacuum leaks, now as i mentioned before in previous threads the thermactor system is gone no more air pump or any of the plumbing both solenoids going to the thermactor system have been disabled so they wont dump vacuum into nothing and the cross over pipe along the back of the cylinder heads has been capped

ive put in a new timing chain, and im wondering if that could be causing an issue, i rebuilt the distributor awhile ago, when i reinstalled it i bumped it toward the left bank a lil more than it had been an the engine ran smoother than it had previously, might i have to re adjust the distributor because of the new chain? it has all new MSD wires cap and rotor in it along with a new coil and E3 diamond fire plugs
the EGR valve is functioning properly i checked to make sure the diaphram opened and closed properly and all traces of code 33 have vanished

im not sure where to start looking any help would be much appreciated i dont like it when my truck runs this way

 

Well with no codes u need to isolate which cylinder is missing first u can do this by pulling one wire off the distributed at a time with it running u should notice a big change in idle if that cylinder is firing once u found the cylinder misfiring u should start by pulling the spark plug and examine it compare it to other plugs that u know are firing properly u may have a bad plug u can swap plug to a different cylinder and see if miss follows if not u can also swap wires around if miss stays at same cylinder u need to run a compression test and then a cylinder leakage test hope this helps let me know if u have any questions

 

okay will do, im wondering, the driverside portion of the exhaust y pipe has come loose, could the uneven back pressure cause a miss, its not severe, it really isnt even noticeable unless you listen really close to the exhaust in the cab and under the hood its sounds smooth ill have to pick up a compression tester that and a vacuum gauge this wednesday

i did change the plugs over today, i got rid of those stupid e3 diamond fire plugs and got a set of motorcraft platinums the electrodes on the first three cylinders of the left bank were damaged they looked like they had gotten really hot and im wondering if thats due to the loss of backpressure on that side
also it only seems to miss after having been driven for awhile once it warms up the miss starts up, thats why i suspect the intake gaskets, once the engine warms up and all those seals expand it starts missing, that and i noticed my power brakes were a lil stiffer than normal today like they arent getting enough vacuum, the booster is fine it isnt leaking, id hear it hissing from within the cab
ill check to see which cylinder is misfiring tomorrow

 

Thought my truck was missing once, but I went around the corner and there it was. Sorry, I don't have anything intelligent to add.