350 studder

[murfs70]

have 70 3/4 ton 4x4 350 has 1000 miles after rebuild,edelbrock cam,edelbrock performer intake,mallory unilte distributor, holley 4150 carb k&n filter. timing set at 14 degrees initial (as per cam) total set at 36 degrees.truck used for desert trips only original problem was pinging,had plenty of power ran great took it to be dyno tuned then problems started hooked up to 32 foot toybox truck fell flat on its face i set timing to where it should be or at least i think where it should be because dyno place had it screwed up, truck runs ok now but not as good as originally, has a studder at high rpm under load and doesnt seem to have the power it had before dyno tune not sure if fuel or ignition. would appreciate any help or suggestions thanks.

[truckdude239]

try another carb i've heard alot of bad things about holleys got an edelbrock intake and cam why match them with and edelbrock carb

[MisterMan]

Originally Posted by truckdude239

try another carb i've heard alot of bad things about holleys got an edelbrock intake and cam why match them with and edelbrock carb

so have i, 1st thing tho, drain all your fuel of the tank, then start er up and run everything empty, then add some 92+ octane fuel. a lil cheaper than replacing the carb just to see if ya solve ne thing.

[Daubs]

Hmm. I've been having problems with my crate 350 (Edelbrock intake, Holley 1850, ram-horns, HEI, stock cam). Messed with timing quite a bit and finally decided to time by feel -- keep advancing until I hear pinging under load, then back off a little.

I've decided to ditch the Holley. Have an Edelbrock 1405 in the box...purchased today. Hope that helps solve my problem.

Has your Holley been rebuilt? Or is new? Or from old engine?

[murfs70]

fuel is fresh in tanks was a brand new carb when i built the engine,have been thinking about getting edel brock carb the only thing is it ran great except for pinging under load until i had it dyno tuned.

[MisterMan]

i gurantee when they dynoed it they did something as small as set your timing off, made the coil wire loose, dis connected a few spark plugs by accident, something really small. dads truck was spuddering one day, drained the fuel to find massive amounts of rust in it. some one added bleach or clorene to it. not saying it was sabbotaused but... maybe??? me no no man! lol. just check the small stuff.

--den

[greasemonkey]

I get better performance out of my Holley than I ever did out of the Edelbrock. A lot of people bash them because they are harder to tune, but once correctly tuned, they are much better performance wise (imo). Edelbrock is a good hassle free carb with better fuel economy.
Since your timing is the same as before, I would check all your carb settings again; especially float levels. Also make sure that your fuel tank/cell is vented properly. Is the fuel filter new? Fuel pump? If it backfires through the carb it is probably lean; a backfire through the exhaust means you might have a fouled plug or crossfiring plug wires.
You might want to recheck the valve lash too. You might have a couple valves too tight.
I just went through this same thing myself (cutting out under load), it turned out to be blocked vents on my fuel cell.
Good luck.