Carb and auto tranny questions

WACO · Feb 3, 2008

I have a '74 Dodge D100 (318 2bbl/727 auto) that I am fixing up to drive on the road reliabley, and I just rebuilt the carb today. The thing runs AMAZINGLY well, until I am on the gas hard or pulling a hill, once it gets about 3000 RPMs the power kind of goes away and the engine hesitates, and the exhaust blows black. Any ideas? I have never worked with carbuerators before.

Also at the same time, the trans suddenly started acting up. It won't go into 2nd gear until about 20 mph and then shifts harder than normal. Also, it does not have 3rd anymore!? The fluid is full and looks good. The transmission didn't feel 100 percent before, so maybe it is on the way out and just was a coincidence? Any ideas? I have never worked with autos before either

Thanks

GaryTJ · Feb 3, 2008

both sypmtoms can be from excess manifold vacuum. (caused by running out / low on fuel) check fuel pressure and especially volume from the pump and possible float level set too low.

WACO · Feb 4, 2008

GaryTJ said:
both sypmtoms can be from excess manifold vacuum. (caused by running out / low on fuel) check fuel pressure and especially volume from the pump and possible float level set too low.

Thanks for the reply! I have a feeling the trans issue is related to the carb.

Would the running lean condition though make the truck throw black exhaust?

WACO · Feb 5, 2008

Well I figured out the transmission, I didn't hook the kickdown cable spring up correctly. It works as good as it did before now.

WACO · Feb 6, 2008

Replaced the ignition module and coil today and it feels like the problem went away. Still didn't feel like it had the throttle response though and the idle quality started going down/didn't sound right. After being frustrated all day I finally figured I had nothing to lose and started fiddling with the mixture screws, and writing down how much I moved them just in case. The first one I turned one direction just slightly and the engine almost stalled. So I moved it 1/2 turn the other direction and the truck came to life! Ended up turning it another half turn, then adjausted the idle back down. Went for a test ride and it has way better throttle response and power. Still blows a little black exhaust under a heavy load, so a little more tuning is needed.

WACO · Feb 11, 2008

Well it still wasn't fixed. I pulled the plugs out and the driver side bank was running really rich. the brand new plugs were already fouled. So I cleaned all the plugs and put them back in. Then I tore the carb halfway apart and checked the floats now knowing some numbers. Indeed they were too high so I set them down to 1/4 inch below the top (where they are supposed to be). Also learned some things about the mixture screws and got them both on the same page, and leaned up the mixture about 1 turn. Also advanced the ignition to just below where it starts to ping under a load. Well after a lot of test drives and fine tuning, it is finally fixed and runs like a champ!