I have two questions for you guys. I bought a 94 civic cx hatch after my si was stolen recently. It came with a b18c1 but running on a p28 Ive concluded that it wasn't chipped because it was making the power of a 1.6 liter. The vtec kicked with the p28 but I now I have a p72 in it and te vtec won't kick. Yes te check engine light is on. Is it only the knock sensor I have to wire up or is there more?

Now for my cluster problem. I bought a new one because it had no tach. I plugged the new one in after I bought it last night and everything worked fine drove probably 100 miles and then the speedo stopped working. It turned back on but seems to be readin like 10-20 mph off an is really jerky. Any reason for this? And the old speedo work fine.

 

Your speedo probably has defective solder joints (This is a known issue.) Best approach would be to use the circuit card from your old cluster if it works. Otherwise, you will have to hunt down what needs soldered or try and trouble shoot the circuit card.

 

Oh...
It would happen spontaneously like that?

 

Vibration can do that. Mine decided one day it would sit 20 mph higher than what my actual speed was. Then there was the day it decided it wanted to sit at the other side of the 0 peg. And a week later it decided it wanted to work normally for a bit then jerk and waver about. I swapped the circuit card from known good cluster with messed up needles (PO broke one) and havent had any problems since.

 

Would it be hard To switch them? I have one cluster with a tach and one with out.