I just swapped a sohc zc into my 91 hb, everything was good until it threw a code #4, crank angle sensor. I changed the dizz but still the same problem. The motor will let me go up to 3200 rpms, and then start purging, like a hiccup. could anyone help me please. thanks
mike

 

check your timing

 

bump........................

 

Code 4 is for the Crankshaft Position Sensor. The most likely problem is an electrical problem. I think that the sensor might not be sending the PCM a signal, in which case your engine will not start. Check the wiring for the Crankshaft position sensor.

 

Did you do a wiring conversion yourself?

 

yes i did the wiring myself. it just so happens that i got 2 bad dizzys consecutivley. but i got the lifetime warrenty, so i swapped em out twice in a row. but i got a new problem. after all that, i got it running again. but now its throwin a code 9. so ill have to look into that tommarrow. Thanks

 

Dude, I had same prob just the other day. I replaced dizzy witha new one and prob went away...
For Code 4 Check for resistance accros the Crank angle sensor.. you should get arround 400 to 700 Ohms Check if any wire is shorted to ground. After all the sensor is nothing but a wire wound coil magnet that can overheat and burn out giving an open or short circuit reading. If resistance is ok put the plug back in and check at the ecu harness connector pin 10-12 you should get 400 - 700 ohms if not your harness is no go.
Code 9 is your CYL sensor which is located in you r dizzy as well, and same connector there you should get 700-1000 ohms. check if there is short to ground. On the cpu side these are C1 and C2 connectors.

Hope this helps.

 

Thanks alot for the write up, i figured it out today. i was throwin codes 4, 7, 9. code for was the crank sensor, new dizzy fixed that. code 7 was the tps sensor, new throttle body fixed that. code 9 was the tdc sensor, took a while, but figured out that i had to of the wires crossed at the ecu, fixed that. now she pures like a perfect kitten. no codes, good performance, and now i am a very happy zc swapper. I thank everybody for all thier input. happy tuning.
Mike

 

Glad to hear it.