That was my first issue. Because of that issue I changed the distributor, and now all distributor related parts.

after the distributor change the truck is not drivable. Stuttering, dying, feels like misfire every time I drive. When it’s cold, it’s really bad. After it warms up you can feel the misfire when going highway speed, but not when idling or driving slowly.

before it only gave me trouble once or twice a month.

 

If the engine ran worse after the distributor change, I would put the original one back on because there likely was nothing wrong with it or start diagnosing the one you installed.Also make sure the wires are installed in their proper spot on the cap.

 

I wish I could.

I tried to change the pickup on that distributor and accidentally broke it beyond repair taking the gear off.

that’s the only reason for the new one.

 

I hope you installed the dist properly, because if you did not , it will never run right.

I can provide the procedure to install it properly , but it is somewhat lengthy and I would like to be sure before going through all of that.

So,,,,,,,,,,,,,tell us EXACTLY , how you installed the replacement distributor.

If I see what may have been overlooked I can help you out,,OK ?

 

Cranked truck until cylinder 1 was all the way up. Checked by pressure blowing out on spark plug hole, with my thumb, and mark on flywheel.

pushed distributor down into place with rotor pointing to the “1” position.

plugged in wires with a firing order of 1,3,7,2,6,5,4,8 going counter clockwise.

timed using 10 degrees BTC with the timing spout unplugged.

Spark plugs were changed to try to solve problem. Old and new spark plugs were both gapped at .042-.045.

I have timed this truck before, and installed new spark plugs before with no issues about 2 years ago.

 

OK, You must mean the timing mark on the crank pulley , which as I recall is a stinker to see.

If you installed the dist 1 tooth off, that will give you the symptoms you are seeing.
I just know you are going to love this, but you need to do it over again
YOU CANNOT CORRECT FOR THE GEAR BEING ONE TOOTH OFF BY TINKERING WITH ADJUSTING THE DIST WITH A TIMING LIGHT, IT DOESN'T WORK !

You need to start from the beginning and #1 piston must be on compression stroke , that TDC mark on the pulley MUST be perfectly aligned with the pointer on the timing gear cover.Look straight down.
If you rotate the engine in the normal direction of rotation manually ( you can use the alt pulley to do this,) you cannot go past the mark and back up , wear in chain will get even with you, . You may need to rotate the oil pump a little to get that rotor pointing EXACTLY at #1 post inside the cap. when the dist is ALL the way down..
You can do this , now you have some idea it is critical to be on the money..
Have repaired many with sheared pin holding gear on to shaft. If you are particular and fussy to to it exactly right , the payoff comes when you crank it up and it runs great.
By the way if you decide to adjust timing with the light now , it will work.

 

Replaced the distributor, did the timing process again, and still bad.

im completely out of ideas at this point. I’m going to take off and clean the egr tomorrow.

Replaced the egr sensor, throttle position sensor today. No improvement.

 

Must be getting expensive when you guess and start replacing parts without testing them.

 

Still no idea what's wrong with it.

 

Let's start with proving out the ign system.
My first check would be to connect a simple test light to the wire connection coming from the igh sw to the coil.Must be done AT THE COIL.
As long as there is power the test light should stay lit. What we want to prove is we are not losing power to the coil as the vehicle is being driven..
Place the test light where you can see it at all times. You may need a long piece of wire to verify this , but there is no other way to do this.
If it goes out an any time , you could have a questionable ign sw.
Drive the vehicle some and let us know what you get,thanks.