i just replaced my distributor cap and rotor arm...i know that the timing is controlled by the computer, but the car is sure behaving now as if the timing is off. do i need to at least get it close somehow?

 

probably would help if you mentioned what model car and year, and/or which engine (b21f, b230f, etc)

 

ah so sorry....1990 240.

 

so the distributor is on the end of the crankshaft at the back of the engine.

if you just replaced the cap and rotor, and didn't remove the distributor body, it should be just fine the way it is. sure you got the right plug wire on the right spot on the rotor?

 

Um - on the 240, the distributer is up towards the front of the engine on the left hand side and is driven by the halfshaft. You are correct that for a 1990 model year, the timing is electronically controlled and the signal used to drive the timing is from the crank positioning sensor.

You say that it has the symptoms of the timing being off, what kind of symptoms are these?

 

i'm pretty sure i have the order correct. i took the wires off one at a time and then checked the order in the manual.

i had replaced the cap rotor and battery because the car seemed to have spark sometimes and others not. with the old battery/cap/ rotor the car was having cold start issues. when we investigated it, we found that it was getting spark on some startups, and not on others. with the new battery/cap/rotor the car seems to start, but is definitely misifiring or missing. it is surging at idle, sometimes cutting out, and there is a not so good combustion spell.

i am not sure if i've caused a new problem and solved an old one, or if i have simply transformed the orginal problem.

 

If you are getting spark sometimes and not others, I would take a look at the crank position sensor. It is mounted on the top of the bell housing where the engine and transmission are bolted together. It has a wire that goes up to a connector on the firewall. If this wire is cracked or frayed, it may be not be functioning all the time.

If the idle is surging, I would look at the fuel system. Check for vacuum leaks. Also check for leaks in the accordion air intake hose.

 

+1 on what act1292 posted. Do a little research about removing the CPS. I replaced mine simply because it was the original from 1990, sure enough the wires were frayed. I was very lucky, when replacing mine it came out easily. I have read posts here and other forums about the housing breaking on removal. It isn't a bad job otherwise.

Good luck