86 GT hesitate

[Larry]

Hello everyone .. I bought and 86 recently and well it's been not fun lol it was and efi but I like my carb so I bought a kit and now it hesitate when I put it to the floor anyone else have this issue this isn't my first efi to carb swap but this is first of this any info would be greatly appreciated thank you!

[richpet]

Many times a hesitation is due to too much fuel at the start.
You've done q carb swap - how big is the carb? Motor stock? Jet size? What carb?
More information would help.

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[1982GLX]

Do you have a fuel regulator? EFI puts out a lot more PSI than a carb would.

[richpet]

Many times when you floor it there is a dump of fuel. If that dump of fuel is too much for the motor to handle even with the air butterfly's all the way open, you end up with a drop in power for a second.
How much of a hesitation are you talking? Is it minor but noticeable? Is it so major your head falls forward for a second instead of backwards?
A little more info on your combination and a better description of the bog down can help folks try and help you. A couple of us have asked questions and need your replies.

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[richpet]

Did you get it figured out?


Added 1/27/22:
Assuming yes since you haven't been back? We like good news, too.

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[Four Eyed Fox]

Man swapping to carb? FI is the chit...sorry I grew up with Carbs, when FI came out it was just so much better in terms of maintenance...

[richpet]

Don't know. He hasn't seemed to have returned.

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[Shoegazer GT]

I'll be watching this thread as I'm having a similar hesitation on my '85. My setup is a 750cfm 4150 (wouldn't have been my first choice, but the PO had it on the car when I bought it,) and the engine is relatively stock - longtube headers and free-flowing exhaust is about the extent of the mods. My guess would be the primary shooter is too large, at least in my case, as the smallest shooter I had at the time was a 25 which still produced a momentary flat spot when I snapped the throttle open, and anything larger produced an even more pronounced hesitation.

[Bentley]

WAY OVER CARBURETED..... Very common mistake made by us back in the day..... I wouldn't use a 750 on my 440 dodge....
I will disagree with all who say it is " a big dump of fuel" when its a big dump of air with NO fuel on an OVER carbureted car....
The bog felt when secondarys are " kicked in" is because of NO fuel, hence the reason for double pumper carbs....
Just rebuilt an Explorer engine with P heads.. I have installed a TF stage 1 cam and shorty headers.... Going to use a 500 CFM Summit carb and expect it to run very well with good street manners...... CFM flow chart shows 472, CFM at 5500 RPM.....

[richpet]

Sounds about right. That's a lot of carb on a relatively stock 302. A fuel dump will create a hesitation as it goes through mostly unburnt.
Heck, the stock carb was under 600 cfm.
My moderate 306 ran a 570 carb very successfully years back. It could have used a little more, but it was very streetable and respectably quick.

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