Well, the 79 I just picked up had a weber 38, long story short when I am in the upper rpm range the carb will sputter as if the throttle is opening and closing rapidly. What could be causing this, leaning out maybe. Any ideas would be good. Chris
take apart the weber and make sure all the emulsion tubes are clean and all the jets are clean too. I know when they get plugged up with crap you get werid running issues.
sorry i forgot to ask, what are you useing for a fuel pump? are you running the stock mech or did you do an electric swap? ive heard the mech ones sometimes make crazy off fuel pressure numbers which may cause this problem. i have not personally ran the mech one, when i swapped my weber on i dropped an electric pump in as well.
I second that! Check the common, easy, and cheap stuff first before you tear into the carb. A few bucks on a new filter couldn't hurt. Also take off your fuel line and see if the flow of gas is steady looking (catch it in clean container, it should come out with a pretty good amount of pressure). You have an electric pump I believe in that truck unless someone swapped in something, so just turn on the key and it should start pumping. Have a helper do it while you are out under the hood holding the container and fuel line. You don't want to see a lot of air or unsteady flow coming out.
New filter, in tank electric but for some strange reason it stopped all of a sudden, now she pulls all the way with out problems. I guess it's just one of those things, I'll wait for it to show up again but for now it purrrrs like a kitten and pulls like a banshee!
My '79 4x4 used to give me problems with the stock electric fuel pump when I'd go through deep water crossings and I ended up adding a backup fuel pump in line under the hood mounted on the fender. I still run the stock fuel pump in the tank, but if it cuts out I have a backup fuel pump on a switch on the dash I can turn on. I suspect your fuel pump or the power supply to it might be the culprit here. It sounds like it wasn't getting a good gas supply. Unfortunately with it only happening intermittently it is going to be hard to pin down for sure that that is what it is. If you end up adding a inline fuel pump, there are different pressures. Like for example the NAPA inline fuel pumps, they come in a lower and higher psi version, I think the lower is 3.5 psi or something and that is the one you want. The higher psi one will overpower the float and flood your motor. Glad to hear it's working right again for now anyway.
