305 QJet Problem

[76C10Stepside]

Thanks, man! PM Sent!

I thoroughly cleaned the carb, polished the throttle bores, etc. Put it back together and installed on the truck last night. The Throttle worked, but it would not idle.

Today I found that the choke butterfly was not closing all the way, sticking. A drop of oil on each end fixed that. Truck started and idled ok at first, then started idling waaaay too fast. Found gas dripping from the inlet, and fuel vapor coming out of the front of the base gasket.

Tried to stop the leak, no go. When I put the inlet back on last night, I used the two gaskets that came in the kit (black with metal core and red paper), instead of just using the black one. I've had problems with the inlet coming loose in the past and figured two gaskets are better than one. Guess not. Will remove one gasket and see.

The base gasket was new, but last time I pulled the carb off, the new gasket left some bits of the paper top layer behind. When I put the carb back on last night, I put a little oil on the mating surfaces to keep them from sticking again. I'll put the old base gasket back on tomorrow.

[76C10Stepside]

OK, got the leaking base gasket and inlet fixed and oiled the throttle shaft. Engine starts and idles normally, and throttle returns properly when I let off.

I THINK I know why the throttle plungers have that spring on top? When I hit the throttle, the engine stalls the first time. Hit it again, and the engine responds a LOT faster than it ever did before. It lets off fine. Maybe the top spring is a "buffer" that makes the throttle "ease in"?
Ideas? Opinions?

[76C10Stepside]

Installed new rear shocks last night. Took it for a short drive today to check out the ride. It started easily, and after about a minute, I was able to drive it, with the manual choke closed. Before the rebuild, it would stall if I tried to drive it before warmed up.

Drove it to the post office, a little over a mile, with choke still closed. The throttle responded great, with no hesitation at all. It's still VERY responsive, hard to believe the 305 should have this much power. Feels TOO responsive.

Opened choke for the drive home. Throttle hesitated again like last night, but not quite as bad as before, and after the initial hesitation, throttle response was great.
Got home and could not get it to kick down from fast idle. I oiled the throttle shaft last night, so this may be due to the jury-rigged throttle cable--it's wire-tied onto a makeshift bracket, and may be binding.

I need to get the automatic choke working. The choke pulloff leaks, time for a new one. The auto choke was staying open when cold, and closing after warmup or not (already tried reversing the linkage with no change). Last time I followed the procedures and it still would not work right, so gave up and installed a manual choke.

Also need to get a quality wrapped fan belt. The cheap one I got when I rebuilt the top end squeals like crazy no matter what the tension is.

[76C10Stepside]

Got a PM from raws67 today notifying me that a correct donor throttle plunger is in the mail. Thanks buddy!

Got started on removing the old wood bed yesterday, what I could get done with only one working arm. Cut through the wood and carriage bolts to release the rearward cross-support so it can be relocated farther back. This is the part that's directly over the shackles and needs to be cut or moved to make room for 2-inch longer drop shackles.

Looks like it can be moved back just enough to clear. Only problem with that plan is, the row of holes in the steel bed "ribs" will be in the wrong place.

Or, I could do as others have suggested and cut or notch the cross-support. If I go that route, I think I'd want to weld some square tubing on the sides to make up for the missing part. Half an inch thick is not much of a floor!

[76C10Stepside]

Thanks to raws67 who sent me a good throttle pump! Engine runs great now! Better than ever before. :-) When I went to install the new/used pump, I found that a top corner on the plastic float had been ground down by something. Seems to be ok otherwise.

Spent the last two days tearing out most of the truck bed, cutting out the rear cross brace and installing 2-inch drop shackles. The truck doesn't really LOOK lower to me, but the new shackles reach all the way to the bottom of the boards, so I know it's lower. Will be cutting one coil off the front springs before deciding if a flip kit is in my future.