NorCalDiesel
New member
Just kidding about the swap, although it would be nice.. And I won't lie I have thought about it.. But I will settle on the 304.
Anyhow, I have been struggling with getting this carb on my 304 set up correctly. Here is some history. I got this '70 s800a in March '10 and put it back on the road after sitting for 2 years. Before it was parked 2 years back it had about $1800.00 in work done, mostly under the hood and fuel system.
When I got it I changed all fluids, flushed the tanks and replaced the points (.019), plugs, rotor, cap, wires and cleaned it up. It started and I set the timing at about 5*btdc, but it ran poorly. I moved the timing around a bit but settled on 5-6* btdc. At that point I rebuilt the carb. I got it running and set the idle and it ran pretty good. Not great, but a lot better. I had a bit more to do to get her roadworthy so I focused my attention elsewhere.
I have accomplished a lot since then, rebuilt suspension, new bushings, body mounts... List goes on. But I now have a progressively sickening engine.
Over the last 4 - 6 weeks I can't seem to get the engine to stay in tune. Initially I began to experience crossfire, or what I thought might be crossfire. In retrospect it May have been backfiring both through the exhaust and carb. I found a couple posts discussing wire position and I went in and rearranged my plug wires and it seemed to remedy the problem. A couple weeks later same thing. Backfiring through both the carb and exhaust.
I went back and checked points gap and timing and both were unchanged and good, points gap .019 and timing 6*btdc. I moved the timing back a couple degrees to about 9* and the backfiring is gone. I am thinking great finally get her running good.
But a couple days ago after getting off the freeway I could not get the idle down. Pulling to a stop on the exit ramp the rpm's stayed around 1500 and would not come down. So I pulled off the road and adjusted the idle down manually. I know that is not right, I just wanted to get home. Now I have gone through both the timing and carb settings but can't get the idle to stay put. If you just start the engine , hot warm or cold it will idle around 700 rpm. Run through the gears and come to a stop the rpm will be around 1100 and will stay there.
Right now I just want to get the idle to stay and go from there. I can't even get a good look at the timing as it is moving about 5* back and forth as the idle moves around.
The engine is a 304 original to this s800. Holley points dist and Holley 2300 2bbl (360771-c92 / list 4079-1). The carb is well hammered from the po. The acc pump arm has been bent and straightened a couple times as has the throttle linkage. The carb has soot from backfiring.
I am looking for pointers as to where some of you May start looking. I know it is either the dist or carb, but I would rather not replace both. I am not in love with points ignitions, so any recommendations for other better dists/ignition options are appreciated. I would really like to get better than 12 -13 mpg.
Anyhow, I have been struggling with getting this carb on my 304 set up correctly. Here is some history. I got this '70 s800a in March '10 and put it back on the road after sitting for 2 years. Before it was parked 2 years back it had about $1800.00 in work done, mostly under the hood and fuel system.
When I got it I changed all fluids, flushed the tanks and replaced the points (.019), plugs, rotor, cap, wires and cleaned it up. It started and I set the timing at about 5*btdc, but it ran poorly. I moved the timing around a bit but settled on 5-6* btdc. At that point I rebuilt the carb. I got it running and set the idle and it ran pretty good. Not great, but a lot better. I had a bit more to do to get her roadworthy so I focused my attention elsewhere.
I have accomplished a lot since then, rebuilt suspension, new bushings, body mounts... List goes on. But I now have a progressively sickening engine.
Over the last 4 - 6 weeks I can't seem to get the engine to stay in tune. Initially I began to experience crossfire, or what I thought might be crossfire. In retrospect it May have been backfiring both through the exhaust and carb. I found a couple posts discussing wire position and I went in and rearranged my plug wires and it seemed to remedy the problem. A couple weeks later same thing. Backfiring through both the carb and exhaust.
I went back and checked points gap and timing and both were unchanged and good, points gap .019 and timing 6*btdc. I moved the timing back a couple degrees to about 9* and the backfiring is gone. I am thinking great finally get her running good.
But a couple days ago after getting off the freeway I could not get the idle down. Pulling to a stop on the exit ramp the rpm's stayed around 1500 and would not come down. So I pulled off the road and adjusted the idle down manually. I know that is not right, I just wanted to get home. Now I have gone through both the timing and carb settings but can't get the idle to stay put. If you just start the engine , hot warm or cold it will idle around 700 rpm. Run through the gears and come to a stop the rpm will be around 1100 and will stay there.
Right now I just want to get the idle to stay and go from there. I can't even get a good look at the timing as it is moving about 5* back and forth as the idle moves around.
The engine is a 304 original to this s800. Holley points dist and Holley 2300 2bbl (360771-c92 / list 4079-1). The carb is well hammered from the po. The acc pump arm has been bent and straightened a couple times as has the throttle linkage. The carb has soot from backfiring.
I am looking for pointers as to where some of you May start looking. I know it is either the dist or carb, but I would rather not replace both. I am not in love with points ignitions, so any recommendations for other better dists/ignition options are appreciated. I would really like to get better than 12 -13 mpg.
