Help Needed- Engine Cutout

[Chance66C10]

While driving my 66 today the engine would cutout at 2500 rpm when in third gear. I was able to bring it past 2500 rpms in 2nd and 4th, but for some reason every time I would reach 2500 rpms in 3rd it would cutout. If i let off the gas it would come back on and chrip the tires a little. If I kept the accelerator down and try and pull through it the engine would completely die and I would have to restart the truck. It runs fine as along as I don't reach 2500 rpms in 3rd. Any ideas as to what is causing this?

Truck Info:

1966 C10
307 engine out of a '68
Muncie 465 transmission
Electronic Ignition


Thanks,
Chance

[PGSigns]

Sounds like it is running the carb dry. Fuel filter or pump would be where I would look first. What carb is on it?
JImmy

[Chance66C10]

It has an Eddlebrock 1405 carb. Any advice on how to diagnosis the carb and pump? Any advice is appreciated as I'm still a rookie.



Thanks,
Chance

[TJ's Chevy]

If you were to pull the choke in 3rd would it help keep it going? Sounds like its running lean at that particular time for some reason. Might be that the fuel pump is going out or you have a clogged filter.

[Chance66C10]

The choke is not hooked up. I will have to check the filter and see if it's clogged. I believe that it has a new fuel pump, but I can't be 100% for sure. It just seemed odd that it only does it when in 3rd gear. I can run it at 2500 rpms or higher in any other gear with out it cutting out. It does not backfire or sputter as well.



Thanks,
Chance

[TJ's Chevy]

Could be the ignition to....What's your initial timing set at? My old 292 would cut out Once in awhile at 4200 RPM...and I mean ONCE in awhile...And I think it was either valves or ignition. In 3rd gear the engine needs the most fuel as that's really the Main acceleration gear.

[Slow Build]

Just throwing this out there in case it turns out to be the fuel pump. Edelbrock carbs don't like more than 5.5 lbs. of fuel pressure so keep that in mind if you need to get a new one. You might also check the FP of your current pump.

['63GENIII]

I noticed that you don't have a fiber or phenolic spacer under your carb. When I had the Eddy on mine, it would boil the fuel and create a bunch of weird symptoms kind of like you're describing. Once I put in a 1" spacer, it ran fine although I would agree with previous answers about it sounding like it was getting run dry too.

[scum1]

+1 on the carb spacer.

as far as my carb tuning went. absolute must do's

- spacer
-check fuel pressure
-check float height

i would spend a day though to go thru your timing, advance curve, clean the carb if it hasn't been cleaned, and definitely get a tuning kit with different metering rods, springs, and jets.

it sounds like a lot of work, but its worth it. get a buddy, take your time, and only adjust ONE thing at a time. its really not that bad. and you will learn a lot about your motor.

but i would go richer a main jet and try switching your ported vacuum to manifold, and then re-do your timing curve.it might suit your truck better. thats what really helped mine.