Engine is in an '86 F250 4x4 4 Speed.

D9TE-AB
D3VE heads (I think)
Carter AFB 9755S 750cfm
Duraspark II Ignition.

Timing is at 8* with the vacuum advance unplugged.

I just rebuilt the carburetor. Brass floats were good, missing one step up spring though. Had a bunch of crap in the carburetor. Threw it back on and it does the same exact thing it did before.

I bought new step up rods from Edelbrock and new step up springs from them as well.

I put the same step up rods in as it had before. And I tried to match the springs with the one it had before too. Which I think I did perfectly.

I also noticed when I rev it up the secondaries don't seem to be opening. But on the road (I have not drove it much at all like this) it feels like they open. But I'm not positive.

Personally I think the carb may be junk. If so I was thinking about just throwing a new Edelbrock 1407 on it which is identical to the Carter 9755S it has on it now.



I have not put a vacuum gauge on it yet or done a compression test. That's what's next. I'm wondering if it has low compression in a cylinder or a possible intake manifold leak.

I also pulled the front 4 plugs out, going to pull the back 4 out I just ran out of time today.



The timing was spot on with each flash so I don't suspect a stretched timing chain either.

You can hear in the video after a certain RPM it's like flipping a switch, it runs much better. But below that it's like a couple cylinders are not hitting.

I'm just looking for a second opinion. Or how ever many I can get. I don't want to blow over $300 on a new 1407 and that not fix the issue. This is my first carbureted engine and I have only owned it a little over a month. It's my first V8 as well. Not making excuses for my ignorance just stating the fact that I'm not very knowledgeable about this engine or engines of this type. However, everything stated here I found out on my own, so I do have the ability to learn as I'm mechanically inclined. Thankfully.

Thank's in advance.

 

sounds like a accelerator pump in the carb is bad or not adjusted

 

That's exactly what was wrong. Sorry I didn't come back to this thread sooner. I threw a brand new Edelbrock 1407 750cfm on it and it fixed it completely.