ddecart

Trying to get my Holley 3310 (4160) running.

Float Levels - Check
Power Valve - Check
Idle Mixture - Check

Accelerator Pump - WTF?!

rrrrrr
rrrrrr
rrrrrr
*mash it*
pause
pause
pause (engine just STOPS. engine speed drops from 800 to 500, then it catches its breath)

gone down 2 nozzle sizes (from a 31 to a 25) and up (to a 37). Different pump cam with a more aggressive curve. not much different at all. Certainly no better.

let it keep going and it sometimes backfires through the carb

do a double-pump, light mash let up, heavy mash, and it seems to do ok.

Any suggestions?

GDaina

your accelerator pump gasket, (rubber) may have hardened, and is not flexible no mo, and thus not giving the required squirt. Take the accelerator pump off and look at the gasket.

ddecart

Thanks George.
I should have mentioned that I recently rebuilt this carb and averything like that is brand spankin new. I can certainly see the shot going in. Smaller nozzle makes it last longer and the pump arm is slower to move. Looks like it's all working how it's supposed to, but my engine doesn';t realize it. I need fuel injection!

1979toy

Look for a vacuum leak. It sounds like you've got the wrong size power valve.

ddecart

I'm reading about 12" of vacuum at idle (normal in my car) and I've got a new 6.5 power valve in it.

I'm measuring vacuum from the manifold plug in the runner behind the carb on the Performer intake.

Racer16k

Does this 3310 have a transfer tube between the body and the metering block, or just a hole in the gasket? Also do you have the check valve under the squirter? If not it takes too long to fill the entire path when accelerating. What style squirters are using, tube or no tube?

ddecart

Ummm...don't remember the answer to the transfer tube question. I know I had to know that when I rebuilt the thing, but I'm not sure. Wait. the tube is a TUBE, right? Nope. Don't have one. I don't think.

Just put in a new check valve under the squirter. Little needle valve looking thing.

Been trying both tube and non-tube type squirters.

The engineer in me is torn.
1/2 says screw this, you need a technical solution: FI
1/2 says there's a problem here that needs to be understood and fixed!

UGH!

MotorHead

Dave, might want to remove the Stanley Cup from your hood, it might be restricting air flow, we (Toronto) will try to help this year. :lol:

ddecart

That's a velocity stack! :D

ddecart

Ok, I need to correct what i said about the idle mixture. Pulled the car into the garage and my eyes are burning!

Set it to 1 1/2 turns on each idle screw. Had the rpm at 800. I ended up with the mixture screws at 2 1/2 turns in, and backed off on the idle speed screw a good bit to get back to 800rpm.

I had the same problem with the carb I had on the car previously. Eye burning idle mixture.

Racer16k

Did adjusting the idle mixture help any? Does your 3310 have a secondary metering block or a jet plate? Sometimes when I'm diagnosing a vacuum secondary carb I'll disconnect the secondaries and tie them shut until the primaries act right. Also what spring do you have in the diaphram? It could be too soft.

ddecart

The secondaries aren't opening as far as I can tell. Not sticking my head directly over the carb what with all the fireballs shooting out of it. It was cool earlier, there was excess gas on one of the venturies and ti was burning. :cool:

Anyhow, I've got a factory standard spring in the secondaries. It's a 4160, so a metering plate, no jets.

I thought I had this thing pretty well set up how it should have come from the factory.