cant diagnose problem. please help http://www.nicoclub.com/forums/thread-icons/c

[seaoharrwhy]

Whats up guys. ive got a 1993 240sx and have replaced the timing chain, oil pump spark plugs, wires, distributor cap and rotor. the timing is set to 20*. So here's my problem......after about a week of replacing my timing chain and running fine it started misfiring in cyl 3. it only starts after about 10 minutes of starting it. It's getting spark and fuel. compression is 170 across the board and im out of ideas. if anyone has some thoughts or if this has happened to someone else please help me out.
Modified by seaoharrwhy at 9:31 PM 10/4/2009

[bretjohnson91]

The first places and things i would personally do is check timing, ignitor, grounds, and check your codes. It also could still be a spark issue you have to check how well the fire is make sure injectors are flowing well relays working and fuses are in good condition.

[seaoharrwhy]

so i went to double check everything today. all my grounds are good injector plugs are good, spark plugs look fine, timing is good. So the deal is I went to drive it and it was running fine for about ten minutes......until i gave it full throttle. It is still only missfiring on cyl 3 and doesn't go away unless i let it set and cool off for a couple hours. 2 days before this started to happen i did bump up the timing to 25* and put 93 octane in it but since it started to do this i set the timing back to stock because i thought it might be the problem. any other ideas???? could it possible be a clogged injector, and what is a good way to check for that? please help, i just put money into my car and i wanna drive it.

[seaoharrwhy]

so i got the time to check a few more things today. My check engine light isn't on but i figured i would check for codes anyways. I got a code 21 so considering i have already changed plugs and wires and have been messing with my timing could it possibly be that my dizzy is screwing up? If this is the case is there anyone in the houston area that has an xtra distributor that i could use to test. Hit me up if anyone is able to help me out. I live just south of the galleria.

[vancouverbc]

try switching the injectors

see injectors in tutorials in my signature

[seaoharrwhy]

thanks for the help. im gonna have to get an impact screwdriver to take off the caps though cause the screws are seized up pretty nice. I cant afford that till i get paid tomorrow though....as im completely broke (checks bank acct....balance of $0.24)

[seaoharrwhy]

so i finally got my injector out and moved it to a different cylinder and the misfire moved with it so im just gonna by a new injector. also would putting bigger injectors in now, because i plan on turboing it, require any tuning or should i just find a replacement and wait on that?

[vancouverbc]

so i finally got my injector out and moved it to a different cylinder and the misfire moved with it so im just gonna by a new injector. also would putting bigger injectors in now, because i plan on turboing it, require any tuning or should i just find a replacement and wait on that?

you will need tuning. i put 370cc in my car without tuning and i'm a bit rich during idle. my main problem is that i fail smog tests.

someone is selling stock ones in the classifieds forum.

[rickgerhardt]

I wouldn't put bigger injectors in it yet. Waste of money. Your going to be running way rich at all RPMs. Even with factory injectors WOT is 11.7:1 which is too rich to start with to make optimum horsepower.