1999 5.7 350 vortec P0304 cylinder 4 misfire

[Orpedcrow]

ATTN: Can anybody reading this recommend a specific seam sealer, windshield mounting goo,
or anything else that can be rolled up into a ball that can be speared onto a chopstick
and then inserted through a spark plug hole?

Butyl is super sticky. Can be had in rope form or pulled from the back of a sound deadener like dynamat.

3m’s weather strip adhesive (also know as gorilla snot) is pretty gnarly but there’s a working window between liquid and set.

You could make some pine pitch.

 

[Road Trip]

Butyl is super sticky. Can be had in rope form or pulled from the back of a sound deadener like dynamat.

Exactly right. I've worked with plenty of Dynamat in the past, and that's exactly the
level of stickiness that would suffice. (Just as a backup plan in case the magnet fails to deliver.)

(As an aside, nothing quite like suffering a brain cramp in public. :0)

Good call, Orpedcrow!

 

[alvaroemg]

Ok so I tightened hat but it makes no difference very loose.

I popped the orange gasket out of the Air intake "hat" that sits on the throttle body. it seems this gasket is shot and doesnt seal anything. I ordered some O-rings on amazon that people say fit in the slot where the gasket sits and help seal the "hat" on the throttle body. These O-rings are heavy duty and rated up to 250f so they shouldnt degrade easily.

When i tighten my "hat" using the thumb screw it tilts slightly and is very loose on the TB. So for the mean time i flipped the gasket upside down the bottom of the gasket has more meat on it and still has a proper square edge and i put some grease on it, this helped it seal a little better.

After doing all this i then took off the intake and then sealed the throttle body and wedged the throttle plate open. and contined the smoke test to the manifold but i couldnt see smoke leaking anywhere in the engine bay.

I put a new ECT and IAC in. The idle issue seems a little better but the truck still has the cylinder #4 misfire when going up a hill under load.

The shop who installed the injectors for me wants to take a look at their work to make sure everything is proper because the owner assured me the injectors should have fixed the cylinder 4 misfire. I promise to keep you guys updated because i know misfires on these engines can be a PITA to diagnose

What O Ring did you purchase? I need it for mine as well as it doesn't seat properly and I'm having misfires on my cylinder 2.

Thanks

 

[socal k1500]

Lord almighty that was stressful

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[socal k1500]

Q: Are you hearing the 2 second fuel pump prime when you first turn the key
to RUN but haven't attempted to start it yet?

Please verify that your distributor rotor is pointing to #1 spark plug wire
after bringing #1 cylinder to TDC *on the compression stroke*.

Let's be sure to cover the basics before we start down the garden path.
(Speaking from personal experience. :0)

It’s for sure on TDC #1 , it backfired once pretty loud and then it just cranks and nothing. I do hear fuel pump

 

[Orpedcrow]

Woo hoo! I use a chrome 1/4” extension and a wet finger in the hole to find TDC. There are other more accurate ways of doing it though.

 

[socal k1500]

Woo hoo! I use a chrome 1/4” extension and a wet finger in the hole to find TDC. There are other more accurate ways of doing it though.

I confirmed with my camera it was TDC before I put the dizzy back in

 

[Schurkey]

It’s for sure on TDC #1

TDC-Compression, or TDC-Exhaust?

 

[socal k1500]

TDC-Compression, or TDC-Exhaust?

TDC compression both valves were closed when I checked the camera. I really made sure to double check every connection. Maybe I fouled a plug somehow ?

 

[socal k1500]

Found one spark plug that looked like this and the rest smelled like gas, replaced them all with some spares I had and truck still cranks but won’t fire. My old cap had a crack so I threw on a spare but maybe the spare is bad? The brass terminals look fine. I went through and double checked all my electrical connectors and everything is plugged in.

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