5.7 vortec long crank

[slow_c1500]

So I put the intake back together and fixed the distributor cap. I started it up and it was running really rich, you could smell it from the tailpipe. All codes were still there, with the addition of some MAF and throttle position codes (probably because I didn’t disconnect the battery during the install so the truck knew that some connections were unplugged.)
Should I disconnect battery and reconnect? Do I just need to drive it around for a while so the pcm relearns everything, and wait for the codes to disappear?

I havent replaced the spark plugs yet.

 

[Caman96]

What is fuel pressure and is it holding?

 

[slow_c1500]

KOEO: Still 60 when pump is running, then drops to 57 when it shuts off, and slowly drops down after that. I think it held pressure slightly better than last time i measured, but it still doesn’t stay at 57.

Engine running: holds at 50 psi

 

[Caman96]

57 isn’t bad, but what is it 15-20 minutes later?

 

[slow_c1500]

57 isn’t bad, but what is it 15-20 minutes later?

20 minutes later it’s at 41.

I also just checked the pressure with engine running, it was holding at 50 psi.

 

[Caman96]

Aside from checkvalve or fuel lines leaking I’m stumped too. You confident FP testing equipment is good?

 

[slow_c1500]

I can try renting one from a parts store and compare the readings to see if this gauge is accurate, just to be absolutely sure.

Also i replaced the spark plugs and when i unscrewed the plug for cylinder 7 (the one with misfire) I heard a hissing sound coming from the plug hole, which didn’t happen for the other cylinders. Could this mean anything?

 

[slow_c1500]

Would driving it around be a good idea to maybe get the pcm to relearn and make the codes go away? Or would it be unsafe/dumb to put any unnecessary miles on it?

 

[Schurkey]

Should I disconnect battery and reconnect?

You should connect a scan tool, and clear the codes. See what comes back.

I can try renting one from a parts store and compare the readings to see if this gauge is accurate, just to be absolutely sure.

Probably wise.

Also i replaced the spark plugs and when i unscrewed the plug for cylinder 7 (the one with misfire) I heard a hissing sound coming from the plug hole, which didn’t happen for the other cylinders. Could this mean anything?

Probably means either the intake or the exhaust valve was open, and there was enough wind blowing up the tailpipe or down the throttle body to whisper at you.

I suppose you could be hearing a fuel injector leaking, but again the intake valve would have to be open; and you'd see a leak like that on the fuel pressure test.

 

[slow_c1500]

Ok so I cleared the codes and drove it around for a bit, and it seemed to run great! No codes came back. Still has a hard start but the new spider (and secured distributor cap lol) seems to have shaved off a second or two of cranking.

The hard start conditions are still the same:

Starts normally when sitting overnight or longer

Hard start when it’s been sitting for less than a day.