Very rough idle

[carcanken]

I have a 96 5.7 with 278000 miles. I had lower intake leak and just replaced the gaskets. After changing gaskets and putting back together i am getting very rough idle on startup. Giving gas bogs engine before catching up. Checked codes but none present. Live data shows missfire on 2 & 7. Both are close to 30 in 5 min run time. Others has under 5 each. I did put new distributor in and have checked plugs. Wires only have about 400 miles on them. Checked EGR and it is ok. Checked for vacuum leaks and didn't find any. Replaced MAF but didn't help. Stumped and not sure if it is the injectors or something else. Fuel pressure at 60 so that is good.
Any suggestions.
Thanks in advanced

 

[Schurkey]

What is the cranking compression pressure of #2 and #7 compared to a cylinder that doesn't have high misfire counts?

Faulty plug wires? Faulty spark plugs? 7 and 2 are sequential in firing order, is the distributor cap good? Distributor installed and adjusted properly, so that the "cam offset" is within + or - 2 degrees at ~1100 RPM?

 

[Sean Buick 76]

It’s most likely a spark plug wire shorting out or a damaged plug wire.

 

[carcanken]

Compessiin is good. Have changed out cap. Will try new wires and plugs.

Distributor was installed back in the same location. I did put to tdc to make sure rotor was pointing to #1. Did wonder if it should be to where wire goes in cap or to where electrode is since they are offset.

 

[Schurkey]

Compessiin is good.

WHAT IS THE PRESSURE? Is it different from a "good" cylinder?

Have changed out cap. Will try new wires and plugs.

Cheap caps can go bad in a hurry. How about inspecting the wires and spark plugs?

Distributor was installed back in the same location.

Means nothing. No telling if it was correct to begin with.

Connect a scan tool, look at the "cam offset" or "cam retard" or however your scan tool identifies the cam sensor/crank sensor synch.

I did put to tdc to make sure rotor was pointing to #1. Did wonder if it should be to where wire goes in cap or to where electrode is since they are offset.

The initial position of the distributor and rotor are detailed in the service manual, using the markings manufactured into the distributor housing. But that has to be modified somewhat depending on what the scan tool is showing, after the engine is running.

 

[carcanken]

I'll get the plugs and wires changed out but would that make a difference with the MAF. If i unplug it the idle goed to normal but when plugged in it is rough. Put new one in and it didn't change still idles rough.