1998 yukon Mystery p0300 and rough idle still

[east302]

Spark plug wires are connected correctly? Any cracks in the distributor cap? Try swapping with the other distributor cap - assuming the new distributor came with one.

Cam sensor is plugged in at the distributor? Easy enough to forget to reconnect it.

Worst case, stab the old one back in and see if it fires.

 

[OR VietVet]

Well uh...I had something that's most likely very bad happen. Got the distributor in, got it on the oil pump shaft, (I spent a great deal of time making sure it was correctly seated) put all the parts back together and tried to crank it. Popped off for a second and then stopped. Figured maybe I left my fuel pump relay out and when I go to check, there's smoke coming out of my Intake and my air box...Shit gentleman. Anyone care to tell me what I did wrong? I followed multiple videos to get this distributor in correctly, and I'm really unsure on what happened. I feel as if it's my fault tho.

Edit: according to sources, this might be a backfire? I hope I did the distributor wrong rather than have engine damage…

It likely is a back fire. Are you sure you have the wires ran in the correct firing order? Was it at #1 on the compression stroke and pointing dead center on the timing marker, at "0"? Pics. The cap is numbered after all.

 

[exp500]

You can also scan again for codes with key on. If you want to double check, remove #1 plug, put finger in hole, have helper bump starter until it blows your finger out, look at timing mark on crank,rotate engine a bit clockwise to zero crank indicator using socket on alternator. Then remove dist cap and take pic of position. You may be a bit out of time (rotate dist) or a tooth off, or as @OR VietVet And @east302 said, plug wires incorrect. Sometimes stabbing the dist goes easy, sometimes 3-5 tries to get oil pump lined up correctly (big screwdriver about 20 -30 degrees) I RTV the gasket to dist body and grease bottom of gasket. Good Luck.

 

[OilBurner2003]

Spark plug wires are connected correctly? Any cracks in the distributor cap? Try swapping with the other distributor cap - assuming the new distributor came with one.

Cam sensor is plugged in at the distributor? Easy enough to forget to reconnect it.

Worst case, stab the old one back in and see if it fires.

Update: I have the distributor in. Unsure why I didn't get my notifications from this site, my bad guys. I am able to have the engine to start now. It looks like I just needed to double check my work. it looks like the new distributor did make some sort of a difference, no current misfires. Idles rough, but it is 20 degrees out of spec. Problem is when I turn the cap on the distributor to try and get the correct CMP offset, It bumps the intake manifold before it's even close. like 18 degrees.

 

[OilBurner2003]

It likely is a back fire. Are you sure you have the wires ran in the correct firing order? Was it at #1 on the compression stroke and pointing dead center on the timing marker, at "0"? Pics. The cap is numbered after all.

Yeah I figured it out, I was being a dummy. Had it on the exhaust stroke I'm pretty sure! Update on the situation below.

 

[east302]

it is 20 degrees out of spec. Problem is when I turn the cap on the distributor to try and get the correct CMP offset, It bumps the intake manifold before it's even close. like 18 degrees.

I’d do what @exp500 and @OR VietVet mentioned - align the balancer/timing cover marks and see where the rotor is pointing. It should be at the cap’s post for cylinder #1 - if pointing to the firewall rotate 360 degrees and see where it lands.

Oh, grab a picture of it if you can.

 

[OilBurner2003]

I’d do what @exp500 and @OR VietVet mentioned - align the balancer/timing cover marks and see where the rotor is pointing. It should be at the cap’s post for cylinder #1 - if pointing to the firewall rotate 360 degrees and see where it lands.

Oh, to clarify, rotate the cap, rotor, or distributor?

Edit: you probably don't mean the cap lol

 

[east302]

Lol, sorry - if the rotor is pointing to the windshield when the balancer and timing cover marks are aligned, rotate the balancer around once and stop at the marks.

 

[OilBurner2003]

Lol, sorry - if the rotor is pointing to the windshield when the balancer and timing cover marks are aligned, rotate the balancer around once and stop at the marks.

Here’s the issue before I take it off, #1 terminal bumps intake so I can’t move it anymore to correct offset. Taking off cap and rotating now, will post pic of what it looks like.

 

[OilBurner2003]

Lol, sorry - if the rotor is pointing to the windshield when the balancer and timing cover marks are aligned, rotate the balancer around once and stop at the marks.

Strange. It’s not on the number one terminal, it’s past it. Am I a tooth off maybe?