small block sounds like a tractor?

[TERPU]

Okay, I changed nothin on the engine and all of a sudden very poor idle and the thing sounds like a tractor until you rev it up. I am running a vertex mag, it has plenty of fuel and no bannanas in the tail pipe. Have I dropped a valve? Collapsed a lifter? Or have the plugs just gone bad?visually the plugs look OK.
All help is greatly appreciated.

Thanks, Tim

[AHotRod]

Let me get this straight, you did nothing or changed nothing.
One minute it ran great, and the next minute it won't idle, right?

[Roothawg]

What is the gap on your plugs.
You need .018-.020" because of the weak spark at idle.

[AHotRod]

You are correct on the plug gap!
If the carb setting is to rich on the idle curcuit, you may find that dropping to .016-.017 is appropiate.
Hell, as of late, we have some of our Top Fuel customers ( I work for Champion Race Plugs )now running as little as .013 on the plug gaps.

[Roothawg]

I think I may have washed down a plug today on the Fly. I busted her off after priming and she loaded on the trailer fine. Got to dad's to unload....wouldn't idle...sounded like a tractor...a fast tractor but still a tractor. I'll check it later.. http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[OldCarPilot]

What kind of small block is this?

[Dirk35]

I know this sounds gay, but moisture in the distributor cap will do this also.

Older caps crack easily. I had a S-10 with vortect V-6 that I was sure was getting water in the fuel. Turned out to be cracked dizzy cap after any time I washed the truck or anytime it would rain, it wouldnt run for shit, and itd backfire through the carb.

Same with loose or corroded plug wires.

Its a cheap and easy 1st check.

Check the rotor also.

Oh yeah, after it warmed up, it would evaporate the moisture out and run fine.

[36-3window]

i had this happen to me to a 350 chevy with an edelbrock 600cfm and a dual plane manifold..it ran and sounded just like a tractor!.....we tried everything..points,plugs,plug wires..ran the same.. took apart the carb and found dirt on one side..that was it! with a dual plane manifold, one side of the carb delivers fuel to 4 cylinders,and the other side the remaning 4. with one side of the carb clogged up only half of the cyclinders were not running right..gave it a real nasty sound

[Mojo]

Might be the gas... are you at the bottom of the tank? That happened to me thursday. I pulled into the lot at work, and the car kept stalling. It would not idle for a damn, but once it was reved up a bit it was sorta ok. When in gear, or driving, it would surge bad... like it was suddenly getting all it's power back for a second. This whole time it had a strange muffled / puffing sound, like the plugs weren't firing hot enough. Pretty sure it was the gas not burning right.

I was near empty, so I put some more gas in it, and a couple miles later it was perfectly fine. No crap in the filter, so I think it was water, or a lot of ethynol (is that the alky additive?) or something. No more gas from AMPM / Arco unless I have to...

[TERPU]

Yep one minute great the next crappo!

Thanks Tim

[TERPU]

I am running the same set-up on mine, oh yeah it's a 67-327. Man this thing ran bitchin until today. I'll look at the carb and the cap/rotor. After all this I'll post back. Great thanks for the tips.

Sincerely,
Tim

[TERPU]

Thanks for the plug gap. I just changed to some new ones so I'll re-gap em. This would be a bitchin solution to what my fears are.

Thanks, Tim

[TERPU]

The HAMB rocks again. Crap in the carb and moisture in the dist. Runnin Bitchin!

You guys rule,
Thanks,
Tim

[NealinCA]

Goog news! So maybe you don't have to drive the Honda to Paso and the NHRP http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

Gonna put the 2-4's on now?

Neal

[TERPU]

Gonna put the 2-4's on as soon as I get the other 4. Should be here by NHRP, Lets hope. Still keep your eyes peeled for another SBC. See you soon

Tim