DON S, attn : update on matt's 401...

[Jerk]

Well, I pulled the plugs to do a compression check and guess what, the schrader valve to release the pressure leaks...
Anyway, all 8 plugs are the same color, blackish rust and not really cruddy. the one in #8 has 2 length wise cracks in the porcelain insulatur though, it doesn't leak sparks, and I put it in #2 just to see if my surge was different. no change.

I checked the timing and it is steady on 17 degrees initial, no vac advance.

I replaced ,one at atime and only by themselves, the coil, no change,
the ei module, some change,
and the voltage regulator/condesor thing on the coil, no change.

I cleaned the cap terminals (inner) and the rotor tip. not really any change.

i checked if all sparkplugs were firing, all of them were rock steady,

I adjusted the idle mixture screws, it helped a little.
and the idle screw, not really any better.

I'm wondering if it wasn't the cam? the last edelbrock performer didn't seem to run like this.
I'm assuming if I had a leaking valve, or valve seal or valve guide or weak valve spring that the spark plug for that cylinder would be cruddier than the rest. All of them were actually the same, I couldn't tell them apart at all. I revs to 5000 rpm in park and seems to love it, it doesn't sputter or back fire at all...I'm just freaking puzzled!!! :confused: - Matt

[MIKE HANI]

I'm thinking throttle shaft. Spray carb out or brake clean on both sides of carb while it's running, see if it smoothes out.

[jeepbob]

Matt,
Your problem may be the 17* initial timing. That is an awful lot and the cracked insulators on the plugs indicate detonation. This will also cause the engine to surge a bit.

[Don S]

MattW......Well it sounds you've got a mess...no EGR...Preformer Carb..cracked plugs, with some black on them...cam in unknown condition...trying to opperate at over 4,400'....""wiring is a nice mess thanks to p.o.-sherriff's deputy""
Take a valve out of a tire to fix the compression tester..
Matt...Are the pistons swapping holes??...Does the timing chain have sertain jingle sound??
Just between us, the 1st thing I'd do is ....well forget that...The 2nd thing I'd do is install boesh Platium plugs...and add some upper lube to the fuel tank.....Well Igotta boogie outta here :eek: ......... ;) ....ds..

[Jerk]

ds- the messy wiring is on the wag not my baby- the truck. and the rpm only seldom reaches 4000, hardly ever when driving it.

jb- the edelbrock instructions say another 10* advance may be needed to get the cam to idle nice, I'm assuming this means additional over what is normal like 10* normal, so 20* total?
It doesn't detonate, the plugs were not getting hot enough for that, I run 91 octane and no vac advance with 9.5:1 cr, it is hard not to hear "pinging", "spark knock", "detonation" in this rig. I've heard it before, it sounds like a diesel running, but quieter, and at high engine load, and high rpm. I'll retard it some and see if that helps though, I kinda doubt it, it didn't idle too smooth at 10* initial either.

Mike H- I'll try that too.

[Jerk]

well I lubed the shafts, all of 'em-
no difference.

I retarded the timing back to 10,-worse and back to 5- really bad then ahead to 20, rpm changed with all of these but there was still a miss in all settings too, I put it back at 17*.

I really am thinking its either the cam or the cam, or maybe even the cam. maybe the performer rpm is hotter than the performer? 204/214degrees duration and .448 and .472 lift, all @ .050. 69* overlap. all seem to be pretty mild specs to me. maybe they sent me the wrong one? I have no clue at this point. Thanks for your ears guys! -Matt