97 vortec running rough, need help

[Jkenney_]

Looking for some advice, I had an intake manifold gasket go bad so took it apart to replace them. Ran fine before I did this, put in new fuel filter, distributor cap and rotor, plugs and wires while I had it apart, now it won't idle and sounds like theres a bad misfire. I can get it started and keep it running as long as I manage it with the gas petal. As soon as I take my foot off the throttle it dies slowly

Pulled codes with a cheap OBDII reader and I have 2 P0300's (misfire), which I suspect is caused by the following codes, P0102(Mass airflow sensor), and 2 P1345(Crank position sensor). Could all of these gone bad in just 10 months of sitting there til I got to it? Do I really need to replace all of these items? Any help would be appreciated, its only got 225K miles. Also I started it up without issue 3 months ago to pull it into my garage to work on it.

 

[SUBURBAN5]

How did you set the timing on the distributor?

 

[Jkenney_]

How did you set the timing on the distributor?

That's where my rookie mistake is, I set the distributor pointing at cylinder #1 at TDC on the compression ****** and figured it would at least run and idle good enough for me to get fluids back into it and have it timed. I tried adjusting it in small amounts both ways and still get the same results

 

[SUBURBAN5]

That's where my rookie mistake is, I set the distributor pointing at cylinder #1 at TDC on the compression ****** and figured it would at least run and idle good enough for me to get fluids back into it and have it timed. I tried adjusting it in small amounts both ways and still get the same results

You may be 180 out. Twisting it back and forth wont help. You'll have to start over. Take out piston 1 spark plug and set it to tdc. One way to figure it out is have somebody put there finger over the hole and spin the engine til the timing mark lines up. Before it lines up it should push air out

 

[Schurkey]

I set the distributor pointing at cylinder #1 at TDC on the compression ******

"Pointing" at the #1 plug wire position, or pointing at the #1 terminal INSIDE THE CAP?

There's marks inside the distributor for aligning the rotor. The procedure is in the service manual.

Get the distributor sorted-out, make the engine run, clear the codes and see what comes back...if anything.

 

[SUBURBAN5]

You have to hook up a real scanner and look at the position of you cam. Your goal is 0 fyi. Heres an example of mine.

 

[Jkenney_]

You may be 180 out. Twisting it back and forth wont help. You'll have to start over. Take out piston 1 spark plug and set it to tdc. One way to figure it out is have somebody put there finger over the hole and spin the engine til the timing mark lines up. Before it lines up it should push air out

I made sure to do that but I went out there and did it again and this is where all the marks are at and where the point on the rotor is pointing, just want to confirm this is correct

 

[SUBURBAN5]

I made sure to do that but I went out there and did it again and this is where all the marks are at and where the point on the rotor is pointing, just want to confirm this is correct

That looks pretty close to me. How far off were you?

 

[SUBURBAN5]

Heres a close reference. Take it with a grain of salt because even with the rotors current location it was off. But just an idea of where the pointer should roughly be.

 

[Jkenney_]

That looks pretty close to me. How far off were you?

it is how I installed it, another question someone brought to my attention that it could be a vacuum leak, could that be it? There's what looks like a vacuum line from the drivers side valve cover to something on the intake manifold that is broken. Is that a vacuum line that could cause this?