A little popping From carb.

[philo_beddoe]

I dont want to bother vile, as he's going through a lot right now, but why am i getting a little popping from the carb when i floor it? Thanks

[gunrac]

Sounds a little lean. Maybe timing slipped a bit. I'd check vac. lines 1st. I'm sure vile would be very interested in knowing this.....

[roundhouse]

Describe the popping in more detail

Just a couple times and then it accelerates fine ?

Or does it happen when you wind it up to higher RPM?
And keep popping as long as you keep your foot down ?


Sent from my iPhone using Tapatalk

[philo_beddoe]

Describe the popping in more detail

Just a couple times and then it accelerates fine ?

Or does it happen when you wind it up to higher RPM?
And keep popping as long as you keep your foot down ?


Sent from my iPhone using Tapatalk

Just a couple times, or even once and then accelerates fine.

[LTZ C20]

My best advice to you would be to wait until Vile can take a look. He just spent a lot of time on the truck, any issues you have he will want to address himself directly. It's best not to fiddle around and mess with or change things, you could inadvertently cause other problems. Let him figure it out.

[philo_beddoe]

My best advice to you would be to wait until Vile can take a look. He just spent a lot of time on the truck, any issues you have he will want to address himself directly. It's best not to fiddle around and mess with or change things, you could inadvertently cause other problems. Let him figure it out.

Exactly, i'm sure he'll catch this post and get back to me.

[VileZambonie]

Did you knock a vacuum cap off when you painted your alternator? Sounds like a lean miss. Touch base with me this week

[philo_beddoe]

As a matter of fact both bottom ports were missing those little blue caps you had on there. I found one on top of the manifold and had to make one. They are both capped now. But it did pop after i capped those ports off. I thought for sure that would have been it. I'll get in touch with you.

[blazer74]

  They were blown off when u experienced the popping more than likely. Intake backfire.
Take in mind the carb was originally on a 305 correct.
350's tad bit more demanding.

[philo_beddoe]

Vile, if you catch this....(i know i said i'd email you) the tech at national carb said to adjust the throttle linkage, to slightly bend the rod, so the secondaries open a little sooner. Something like that, does that sound right?

[VileZambonie]

No it doesn't. What I wanted you to find out was it's calibration. Is it calibrated specifically for the 305? If you had a 350 would they sell you a different carb? If so how do they set that one up?  They should be able to answer that for you fairly quickly and easily. With a remanufactured carburetor that you bought specifically for a 305, I need to know it's baseline settings. You have a crate 350 essentially stock configuration so this should be a no brainer response from them. Who did you buy it from?

[philo_beddoe]

National carburetor. I can call them tomorrow and ask them that exactly as you stated.

[philo_beddoe]

Ok, it was not configured for my 305. It is for a 305 - 350, non computer engine. The M4ME was my only choice for the 305. I guess now with the 350, it looks like the M4MC.  Or....4MV. I have read a lot of articles where the 4MV is a pre emissions carb, 60's, early 70's. However it is a manifold choke, what does that mean?? How is that set-up?




Now what?? Can i keep my current carb and be fine? The engine feels like it has a lot more power than the carb is allowing, a little boggy. But i'm not complaining, smooth as glass.

[VileZambonie]

You have an electric choke which is what you want. Find out their settings and jet/metering between the two applications. It's anyone's guess how they calibrated the carburetor you purchased. In the interim a little tweaking may be in order. That base gasket they sent you generally does require re-torquing so pop your air cleaner off and snug the carburetor bolts in an X pattern. Don't overtighten them, just re-snug them. Q-jets require a lot of tinkering to get dialed in but when I drove your truck it wasn't bogging or popping so something changed. Need to ensure secondary air valves aren't too loose and accelerator pump is working good correctly, need to recheck and adjust timing

[philo_beddoe]

In other words, you want me to swing by on saturday with some Dunkin goodies and we'll have a look at it?