99 tahoe missfire

[99 tahoe]

5.7 liter. Cylinder 2 misfire comes and goes. Here's a list of what I replaced: plus and wires, cap and rotor, fule pump and filter, mass air flow sensor, spider injection (upgraded version), temp Guage sensor, upper 02 sensor, purge vent valve sensor, air filter, knock sensor. An ammco shop adjusted the timing and said it was fixed but it came right back.

Sometimes I can clear the code restart it and it fine but it comes back randomly.

Anybody got an ideas? Only code is p0302

 

[strutaeng]

That's a lot of new stuff. All that was replaced in an attempt to fix the issue? EVAP purge solenoid too? Was anything tested to see if it was "bad"?

Assuming everything is good, distributer likely. The gear that meshes into the cam gear wears out, and distributers in general are wear parts.

 

[exp500]

Watch your fuel trims on live data along with misfires . Have you tried another plug wire on #2 ? And were lower intake gaskets changed when injectors upgraded? Lower Intake usually leak #6 or #5 neighborhood for air.

 

[Eman85]

Ever do a compression test? Pull #2 spark plug and look at the porcelain for a carbon track or crack.

 

[OR VietVet]

I would guess an intake leak to check for but also, but swap #2 plug and see if misfire follows.

 

[99 tahoe]

Swapped plug and noticed number 2 was more dirty then number 4 its now giving me a pending code for Bank one sensor two no activity a p0140 that new and I'm also randomly getting a knock sensor pending code but that's new also I'm so over this

 

[99 tahoe]

The The distributor is only about five months old but it is a cheap forty dollar distributor

 

[exp500]

The The distributor is only about five months old but it is a cheap forty dollar distributor

Distributor caps are 1st thing on a misfire. Use Only Delco/Delphi/United DCR820X. Unless of course you like chasing problems.