well, last year passed emissions testing easily with the stock 460 set up. changed out to a weiand stealth and edelbrock 1705 (600cfm) carb shortly thereafter.Also put in new wires, plugs, coil & rebuilt stock distributor.

Now, it won't pass- high HC at idle and load, high CO at load.

Just for the heck of it, thought I'd check wires again. Yep,boots were not sitting down on the dist cap, causing some missing. Ran better, but failed again. Got some proper bosch plug wires and threw the accel universals in the trash where they belong. Then:

1. Unplugged vacuum from advance can, plugged in my vacuum guage. Set idle till port vacuum was zero. (I use ported vacuum, let's not get into that. If I use manifold vacuum, timing goes to 30+btdc when putting the hose back on the can, so its not an option for this truck, maybe it works on yours)

2. kept it plugged and set timing to 12 btdc.

3. Plugged back in. Put vacuum guage on manifold vacuum. Turned each mixture screw all the way in, then out till maximum vacuum, to set fuel mixture correctly (I think, at least this is what I've always done).

still has little power, lugs, shakes at acceleration, pings.

so for the heck of it, pulled the plugs even though they are less than a year old. #3 and #8 had no gap and were arched together. How could this happen- they were gapped fine when I put them in & have less than couple hundred miles on them! could the lack of fire from the wires have caused them to foul? if so, how could they have bent in arch together?





wtf?

Any ideas? running too rich & they fouled? or combination with intermittant firing from poor wire connection ? Or, do I have to suck it up and do a compression test and risk getting the answer I don't want.

It still doesn't run the way it should. It seems fairly even/smooth, I hear no missing any more or rod slap, but there is no "umph" a 460 should/did have & still sucks gas like a pig & lots of smoke from the crankcase breather hose.

 

Those plugs are way black and look oil wet. You have some major blow by it seems. I think a compression check is definitely in order.

 

was afraid you'd say that- its the last thing I was going to do, putting off the ugly R word- REBUILD- as in money

 

any more ideas? I checked the compression, its within 5+/- on each cylinder. the shiny treads are not oil, they are all that way. the black is carbon, which could have come from non-firing.