I just got my car out and the new carb engine runs good.
When I accelerate the carb works fine and when I'm at no throttle, whether idle or deceleration the carb works fine.

The problem is when I try to maintain speed(say 80kmh at 2000rpm)(I drive a 5 speed) the car chuggs like I'm always feathering the gas. What is wrong? I don't have the vaccuum secondary hooked up so its harder to start when its warm, but could this problem be related to that as well?

I'm in a bind and out of cash, so any idea's would be most appreciated.

Dave

 

Might help if you gave some details on the motor. Like what kinda carb it has on it. And why you think that not having the secondaries hooked up makes it hard to start.

 

Sorry bout that.

I was told that with no vaccuum secondary, it would be hard to start when its warm, but it will work better that way.

It's a 1970 350sbc
10.5:1 comp.

the carb is a holley 750 dp with vaccum secondary.

 

ttt

This is a real emergency, I'm supposed to race some punk in a 13 second civic tomorrow after work so I need to cure this problem thanks.

 

Wow, it's good to see people read posts and help people when they really need it.

Wait aren't moderators used for that??

Asking for help on this site is getting more and more

USELESS!!

 

Check your float level the secondary may be sucking fuel out of the bowl giving your surge. Check your fuel PSI are you pushing fuel out of the Jets???



Brian

 

Brian: Thank you for responding and giving me something to go by.

I have plenty of fuel pressure. The guage reads 8-9 psi. As for the fuel bowl idea, thanks, I'll definately check that out tomorrow.

At least after 54 views, somebody has the decency to help another person out.

 

Well I run a street avenger 770 on a roughly 350hp 350 and only run 6psi. Yeah pull the sight plugs out and the level should be lower than the plugs........no gas runs out just at the level.

Do you have a Vac advance on the dist. could the diaphram be moving in and out causing the timing to move on you? This is a little far out but its an idea...........To check this you will need a Vac gauge and a LONG hose so you can watch it when you are at speed........see if you are getiing a surge there. Let me know how it goes.


Brian

 

It is probably a case of 54 people just not knowing how to help you. It happens to all of us, especially when we are in a hurry.

 

Maybe the simple fact that a 750 DP never had vacuum secondaries, never will, and a 750 vac secondary is a differnt carb could be causing people not to respond.

Why would not having the vac secondaries hooked up (if thats what you have) make it hard to start when warm? The engine doesn't make enough vacuum when cranking to open them anyway.

If I disregard what you say your carb is my first guess would be that it's a used carb and you have the wrong secondary spring, change to a heavier spring.

 

Yeah the truth is its either a Vac. secondary or Double pumper so with that in mind I would reconnect the Secondaries. The spring will only operate when you mash the gas not a cruising speeds.



Brian

 

sounds like either timing,or more like fuel filter is clogged or mayby installed wrong. I'm not sure, but from the info given those would be the first things i would check. it sounds like at that speed you are lacking spark timing or proper fuel