1990 240SX Misfire or Timing?

[9t 24tsx]

Hello...Thanks for help in advance.

I did a search and still could not find any help.

Recently purchased a 90 240sx manual transmission. Engine has 244k miles, a ton I know, but it seemed to be well taken care of, oil is clean etc.

Engine ran pretty smooth when I bought it. So myself and a friend changed out the spark plugs with ngk's and autolite wires from advanced auto since my friend works there, anyway...

The car at idle runs really badly with the new plugs and wires. It seems like it is mis-firing, but I dont really know that much about engines...It seems the timing is advanced, Im guessing the previous owner had it this way...not sure how to change that....not sure if the belt is being stretched or what.

We also pulled off the maf and sprayed some cleaner into the throttle body, to try and clean it, it seemed to clean it out, but it still idles really rough, and feels like it is going to die. After around 2000 on the tach it runs pretty strong, with a little hesitation.

Sorry if the post is to long, im just not really familiar with engines, as this is a project car to learn, thanks!

[180fan]

are the ignition wires from the distributor on the right plugs?

[9t 24tsx]

Yes, i switched them around to make sure, but it wouldnt turn over.

[TougeMS13]

Id double check that firing order. And with that many miles on it, replace the O2 sensor, will help with the idle a bit. Your replacement cap should have cylinder numbers on there.

[9t 24tsx]

Im pretty sure the firing order is correct....but what are the specs for the firing order and how would i look to see if it's wrong? I will try and replace the O2 sensor asap, I am running a pacesetter header...so maybe the O2 sensor can expire faster...I shall try it though, thanks!

[TougeMS13]

http://www.zeroyon.com/index/content/view/24/47/

Download the FSM. Distributor car should have cyl numbers next to the posts. count cyl's 1-4 front to back.

[9t 24tsx]

Okay, thanks alot for the link....The only number I see on the distributor cap is a 1, then the rest are blank, damn advanced auto parts....heh..but the firing order should be correct now....havent installed the O2 sensor yet, but wouldnt i get an error or code saying the O2 sensor is bad?