sputters with acceleration

[bucks77ford]

Hey guys, my 75 supercab 460 sputters a bit when 1st accelerating but at an idle it seems to run fine and when going down the road it runs fine. It mainly run rough when starting out from a stop until it gets going a little. I checked timing and I'm at about 12 and tried adjusting the mixture on the edelbrock carb. Nothing changed. I've replaced plugs, wires, distributer pickup and cap when I dragged it out of the trees. It sat for 3 years without running. I did replace fuel filter, but I will change that again too. I'm thinking that the carb needs a rebuild since it sat for so long. Any other ideas? There was a timing mark from the PO when the motor was rebuilt and it was at 12 so I figured that1s where I'd put it. It was at about 14 before with same symptoms.

 

[Workin' Rig]

When mine was doing this it was the acclerator pump. But mine has the stock 2bbl.

 

[Mil1ion]

Acclerator pump or its linkage setting on the lever.

 

[Jolly Green]

If it sat that long I'd say it's time to freshen up the carb.

 

[bucks77ford]

I did take another look at timing and used a vac gauge to try and adjust things again, but still not much luck. It does seem to run really good at times, but still sputters at low rpms and from a stop. I have to get in the throttle a bit so it doesn't do it. I do think it's time to either rebuild it or just go with another one.

 

[bucks77ford]

I put on a new carb (on sale 299.00) edelbrock 1406 600 cfm and fuel filter. I reset timing to about 14 btdc at 600 rpm and retuned the carb a bit. It does run better, but still just a slight dead spot. Its sort of hard to tell since my exhaust has some leaks and needs new. I'll play arounf with timing and tuning some more. Less timing seemed to make it worse. There was a mark at 10btdc when the engine was rebuilt, but I thought that made things worse. I may see what a vac gauge says at 14 btdc at 600 rpms and go from there.

 

[Workin' Rig]

Its a pain to replace but you may have a pinhole in a fuel line aomewhere....

 

[bucks77ford]

It seems to run pretty good right now. I drove it today about 75 miles. Every once in awhile there is a small "hiccup", but quickly goes away. It may just be that's the way it is. I still want to replace the coil, cap and ignition module (with a motorcraft one) just to have things fairly new on the motor. A part of me wonders if the carb mounting setup is doing it. I have the original 460 intake manifold on there without the emissions stuff. There is a plate that has the 4 holes and a flange that covers up an emission hole and then a plate on top of that for the carb. I think I have everything sealed up, but could a very small vac leak do this also. Maybe I'm being too picky and some of what is going on is the crappy exhaust.

 

[midnite]

had a similiar prob outta my 79 here recently. could be some carbon buildup on your plugs. i took mine for a 130 mile trip(round trip that is) this weekend and about 1/2 way to my destination it started doing the same thing i drove it to the parts store and replaced the fuel filter(needed it anyway) tried a different brand of gas and used a bottle of drygas and it didnt help so i decided to pull the plugs and a couple had carbon build up all over them. cleaned them with a wire brush really good and the truck has run fine ever since.

 

[bucks77ford]

Ya, I think I will check the plugs out. I do think it was out of time and running rich when I first got it running even though I did replace the plugs not too long ago. But, it doesn't take much.