318 trys to stall if quick rev?!?!?!?!

[charger318]

hey guys got a 318 in my charger when it is in park if you slowly rev the engine its fine and revs, but if you are in park or drive and slap the gas real quick to rev it trys to stall and die I was messing in garage little bit ago and in park in garage it even backfired through the carb? what you experts think lean? rich? timing?....thanks for advice in advance.

 

[Hemi Rebel]

Lean. Sound like the accelerator pump is not working. Is this a factory stock 318

 

[charger318]

basically stock except for the factory 340 4 barrel intake manifold, and holley 750 vac secondary carb. the previous owner installed this car runs good just if you try to floor it real quick in park and drive it will stall out.

 

[GetX'd]

Sounds like it's dumping too much gas into the carb. Accelerator pump. Be careful. Had that same problem with my six pack. Started on fire and burned a pie circle in the hood when it back fired thru the center carb.

 

[Hemi Rebel]

While its idling, try pushing the accelerator pump lever. Dont touch the throttle, just the pump. See how it reacts

 

[charger318]

wouldn't that just flood it with the throttle plates closed?

- - - Updated - - -

alright so I went outside and pressed the accelerator pump all by itself and I can hear engine bog down from the fuel, so I then went to the air/fuel mixture screw and turned it in half a turn at a time till I heard engine rpm's rise and continue turning till rpm's drop which wasn't till it was bottomed out so I then turned it out only 1/4 of a turn from seated position, it revs better now hesitation but doesn't seem to try and stall so must be to much fuel for her I kind of figured that a holley 750 was big for a 318 with just a 340 intake manifold

 

[Hemi Rebel]

I wanted to test the pump to see if it worked. If you pushed the pump lever and it had no effect we would know it was bad. If it had a major vacuum leak the rpm's would have gone up. We see that is not the case. Now, to the 750 on a stock 318. That is a tad big, which actually makes for a lean condition. What happens is as the throttle plates and venturis get bigger, and the amount of air flowing stays the same, the velocity of the air is reduced. This reduction in air speed means less fuel is being pulled from the bowl, creating a lean condition

 

[sleepar]

600 cfm edelbrock works good on a 318... and is a pinch to big...

 

[rumblefish360]

600 cfm edelbrock works good on a 318... and is a pinch to big...

A pinch? LOL! Well, I'd say that a 318 never seeing more than 5K RPM's, a 570 Avenger would do it. If your seeing better than 5K, then a few more CFM's would help.
I have only used 600's or 650's by choice on the 318's and I have never found a dang thing wrong with that.

The one thing a smaller carb will do for you is increase the throttle response. It also may be possible to find a minor increase in mileage as well.

I have in the passed used a Holley 700 on a 318 with headers.
The worst nightmare was a temporary use of a 800 Holley on top of a 318. What a pain. It took a while to get it to work reasonable. (So glad when the 600 came in!)

 

[WP29440SE]

the 600 is perfect in my opinion and experience for a stock 318. I could never get my 750 holley to run worth a **** on a bone stock teen

at least get a vacuum gauge on it and tune it to the highest achievable number

 

[sleepar]

I run a stock polished' 67 forged internal balance crank and stock rods with arp wavelock bolts, (3) spiral locks on floating pins with kb67+5 pistons 6077 edelbrock heads, weiand (port matched small runner )stealth intake 600 edelbrock carb with electric choke.. stock 340 cam .444 lift... Molly ring at .026 top and .019 bottom std. Bore .004 clearance the kb 167 are 58grams lighter than stock... balanced to 8500rpm sfi balancer melling high volume pump and windage tray. Points distributor.. .039 quench

The 340 intake and 750 carb is too much .... but if you build a stroker 318 with 2.02 1.78 valves x head or whatever.... the intake and carb are ideal. I like the small runner intake for the velocity