a code 4 is the crank angle sensor, right? whenever the ecu is flashing (before cel is on) I can feel a lack of power. When the cel comes on, the power just totally dies and the car can barely move it's own weight. turn it off, coast, restart...drive alittle farther...repeat until parked and reset ecu...repeat every few days. The sensor is in the distributor (?), but can you replace just the sensor?
I also think I recently burnt up an exhaust valve (on a repeatedly overheated head)...seems like the #3 cyl, but can't be sure yet (just happened today)...less power, but mainly shaky engine and different exhaust tone. I'd like to use this as a reason to get a type-r head...is this straight forward, or is there anything I should know first? can I drive on it until the end of the year, or is that asking too much from a machine?

b17-pr3/91 crx

 

OBD 1 car, the CKP is in the distributor, time to replace the distributor. OBD2 car, the sensor is onthe nose of the crank. replace the pickup. and are you sure about the burnt valve? if the car was repeatedly overheated, i would guess headgasket.

 

when you hold a slip of paper at the tailpipe, it alternates between pushing and sucking it back in (instead of a steady pushing). To me, this means that the exhaust isn't pulsing normally. I havn't checked the radiator for bubbling though...
it's a jdm b16 dist, btw.

 

Do a leak down test for the valves...


Jason