Hello,

Having a very frustrating problem with a 1980 B21F - CIS - figured I'd give the board sages a shot before heading to the shop next week. I have some sort of a fuel/ignition issue that I simply cannot resolve.

Pretty typical symptoms, runs reasonably well cold (althought that is changing) but whenever a get on the gas the car begins to buck, not too badly at first but as time and temp continue it becomes increasingly worse, car will die, can keep it running with some heel and toe work keeping the RPMs around 1400 or so, but if I let off the gas at idle it will drop to zero then pop back up to 1000 RPMs or so , then drop then jump etc. While driving the car bucks like a mule. The tach jumps all over the place, real similar to what happens with a bad wire harness, so I am wondering if the cause may be electrical.

Here are the steps I've taken to remedy: new pre pump, filter, injectors and seals, cap, rotor, plugs, wires, fuel relay, timing, Control Pressure regulator. Wire harness if fairly new. All fuses are new, terminals cleaned. Main fuel pump reads fine on the multimeter. Vacuum lines look ok, ground is fine, replaced idle control screw and related o ring.

This vehicle has had an engine replacement (same B21F) but had the problem (to a smaller degree) before the new motor was installed. The case used to be that the vehicle would have problems with just the 'bucking' when gas was at 1/2 tank or less, now it is pretty consistant regardless, and especially bad when turning (not sharp turns, just turning from a dead stop with seemingly no impact on fuel level).

So I give up - any gueses - the nature of the way the thing dies suddenly really makes me thing there is some sort of an electrical problem, but that is just my guess.

Thanks for the input.

JB