Yet another misfire...

[TruckinAin4Sissies]

Alrighty, this has got me stumped.

Prior to this I had a multiple cylinder misfire due to a crack that was in the wall of my dizzy & a stripped dizzy gear.
I replaced the OEM with a MSD Streetfire unit. At the same time I also replaced:
Plugs
Wires
Coil.

Misfire remained dormant for a little while until just recently.

When traveling at freeway speeds (around 2k RPMs) it starts to miss. Drop it down into 3rd gear and bring up the revs and its more pronounced.

Just attempted to duplicate it while in the driveway by revving it up to 1800-3500 RPMs and NOTHING. I then put it in gear and foot-stalled it up to 1700 RPMs and NOTHING.

I do have a MIL for my gutted cats but nothing otherwise.

Any ideas?

 

[Wwildman]

Can you pull up misfire data and tell me which one is misfiring ?

 

[scmsltn]

I had a misfire on my vortec when I bought it from the previous owner. I took it into Chevy and they said the timing was F'ed...so they set it and it ran perfect. Might want to just drop the $100 and have them diagnose it and fix it instead of throwing parts at it.

 

[dirtridinz71]

I had similar problem with my 92 TBI. Turned out to be a bad pickup coil in the distributer. Changed out dist and good as new. A new cap and rotor would seem to cure the problem very briefly too.

 

[chickenwings]

vortec miss around 2k under a load..

bad ground probably at the waterneck or other places in the compartment

 

[TruckinAin4Sissies]

Damn, where have I been?
Thanks guys for the ideas.

No way to pull data.

 

[TruckinAin4Sissies]

I had a misfire on my vortec when I bought it from the previous owner. I took it into Chevy and they said the timing was F'ed...so they set it and it ran perfect. Might want to just drop the $100 and have them diagnose it and fix it instead of throwing parts at it.

I paid a guy to set the timing with a TechII (IIRC)

vortec miss around 2k under a load..

bad ground probably at the waterneck or other places in the compartment

I've done the "Big3" already with no affect on the missing.