Throttle issues - carb

[Ches7911]

I’m almost certain there’s a thread on this somewhere in this sea of knowledge/information but I can’t find it…

I’ve got an Edelbrock 1405 carb that I was able to get dialed in for smooth idle. If I go in easy throttle up/down it’s consistent - if I actuate the throttle fast it dies. I don’t know what to adjust for that response.


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[hsach]

There should be an adjustment for the Accelerator Pump. There are 3 holes you can use, try another hole to see if it helps. An easy adjustment without taking the carb off!

 

[ared77]

+ 1

Hesitation will occur if there is no liquid squirt of gas as soon as throttle starts to move. Look down into carb and watch as you move throttle.

Good luck!

 

[Rustytruck]

If it was mine I would be chasing vacuum leaks.

 

[Ches7911]

I may go back to vacuum leaks searching. Moved the accelerator setting up and down, no change. Getting good fuel through accel pump sprayers.

Watched a video on Mike’s Carb and he mentioned timing could cause similar stumble (haven’t adjusted anything there, old girl has just been sitting awhile)

Appreciate all the responses


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[hsach]

You can also pickup an Edelbrock tuning kit for that carb. It will come with springs and metering rods, both of which you can change without removing the carb. Very easy to go up or down in sizes. Check your timing with a vacuum gauge also, if you plan to adjust it. I would work on one area at a time, check for vacuum leaks first.

 

[m_m70]

I’ve got an Edelbrock 1405 carb that I was able to get dialed in for smooth idle

is this carb new to your truck??

 

[Ches7911]

No not new. Just hasn’t had attention since summer before last. Ran just fine then. I’ve had the carb apart, checked jets and and metering rods for gunk. Everything was fairly clean for sitting that long.


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[m_m70]

gotcha......I'd look again for vacuum leaks. When you set the idle did you use a vacuum gauge? If so, what was the reading?

Are you running your vacuum advance off of full manifold or ported vacuum source?? I've had the vacuum advance canister go bad (busted diaphragm) that caused similar issues.

If all good, check timing and see where that's at......

If it ran good before, it can run good again!

 

[m_m70]

oh......how are your fuel filters??

 

[Ches7911]

Changed fuel filters (in tank mesh & inline) and cleaned gas tank. Distributor is running off ported vac. Haven’t checked vacuum with a gauge. Got a gauge and timing light in today, but my kiddos reminded me I ran out of daylight to try it this evening ha. So I’ll get those vac readings hopefully tomorrow and post.

I did attempt spinning the distributor a bit for additional advance and then retard it to see if that would make a difference no luck.

Best result I’ve had so far is adjusting the idle speed screw in a tad more. Idles faster and doesn’t die on quick throttle, but I’m guessing that’s because I’m pretty much bypassing the idle setting and keeping it at partial throttle set that tight. (Hopefully that wording makes sense)


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[Ches7911]

You can also pickup an Edelbrock tuning kit for that carb. It will come with springs and metering rods, both of which you can change without removing the carb. Very easy to go up or down in sizes. Check your timing with a vacuum gauge also, if you plan to adjust it. I would work on one area at a time, check for vacuum leaks first.

Actually got one of these kits in today also. I was fighting this a couple weeks ago before leaving town for work. Spent a lot of time on this site combing threads and buying tools for when I got home yesterday to start tweaking on it again


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