Edelbrock 1407 off idle bog

[Supercharged111]

Thank you. Wideband is an option that I looked into but i’d like to put it aside at the moment. I think a reliable one does cost some money and really I’d have to do all kinds of stuff to be happy with the install. Further, i have read they can become distracting, and I know for sure that would be an issue for me. I am very close with this and would like to stick with conventional methods at this point in time.

Distracting? No. I have one in 2 of my trucks, Corvette is about to get one too. Besides, you don't need to install it full time. Tune the carb and set the wideband on the shelf if you like. It's what I'll do to my Monte. With a wideband you can calculate your needed fuel area based on your current and the delta in desired AFRs. The old way works and all, but it's not very calculated and you never really know where you end up aside from the car seeming to behave which it can do with crap AFRs. An off idle stumble generally is an indication of 20:1 or leaner AFRs. It won't cough around 17:1, but that's not really where you want to be either. An AEM is only around $230.

 

[78Delta88]

Q Jet is the same issue.. Setup "perfect" but still flat spot off idle. Richen idle up a bit flat spot goes away. Seen it too many times.

 

[Baker7888]

Verified bowls are full?

Yes. Compression is 10.4:1 timing is 18 degrees plus another 16 mechanical for 36 at 3000 rpm plus vac advance off manifold vaccum

 

[78Delta88]

10.4 at 18 at idle?? Try backing your timing down abit.

 

[Baker7888]

Distracting? No. I have one in 2 of my trucks, Corvette is about to get one too. Besides, you don't need to install it full time. Tune the carb and set the wideband on the shelf if you like. It's what I'll do to my Monte. With a wideband you can calculate your needed fuel area based on your current and the delta in desired AFRs. The old way works and all, but it's not very calculated and you never really know where you end up aside from the car seeming to behave which it can do with crap AFRs. An off idle stumble generally is an indication of 20:1 or leaner AFRs. It won't cough around 17:1, but that's not really where you want to be either. An AEM is only around $230.

I have already identified off idle is lean. I just don’t know how to richen it without disturbing everywhere else.

 

[Baker7888]

Try.... Change your springs. It's lean coming into transition.

Springs i thought transition from cruise to power.

 

[78Delta88]

Off idle is lean but just about guarantee your dynamic compression is too high.

What's Your LSA and Intake degrees opening before TDC?

 

[Baker7888]

10.4 at 18 at idle?? Try back your timing down abit.

If i back my timing off it will screw with my all in which i am happy with. I was leaning towards primary jet change or drilling out the accelerator pump nozzle or maybe even a needle change? Just having trouble making sense of the manual.

 

[78Delta88]

If you engine works with what you have, just try richen idle a bit and see if bog goes away...

 

[Baker7888]

If you engine works with what you have, just try richen idle a bit and see if bog goes away...

Idle mix screws? Lsa is 110 i can pull up cam specs in a few if you think it will help