CA Smog help on ka24e

[coolusername]

So there's prolly a ton of threads on smogging a 240 in california, but i didn't find anything that exactly pertained to my issue so i thought i'd post it on here.

i'm looking into getting a 240 near me, and i recently found one on craigslist, but it is registerd as non op currently and can't pass smog.

the owner said that he replaced the o2 sensor and catalytic converter, but doesn't know why it wont pass which is the reason why he is selling it as is.

i figured it could prolly need something like a new egr valve or tps or something, but i'm not really sure.

anybody have any tips for diagnosing to see if it's worth buying and fixing?

like to cl ad:
1989 Nissan 240sx

[FORZA MILAN0]

A high hydrocarbon reading is usually unburnt fuel. If the CO reading and the NOx readings are below the limit then look towards an ignition problem as being the most likely culprit. start checking items and begin with the basics.
Check the plugs first, all of them! One bad plug will give you a miss and everytime the car misfires unburnt gas goes into the cylinder and out the exhaust which raises the HC. Same goes for the wires (check resistance with a multimeter) check the distributor cap & rotor for cracks, corrosion or burnt areas. Might want to do an injector service , a sticky injector might put fuel in at times when its not supposed to and up goes the HC. If the check engine light is on 1st thing to do is pull some codes and this will give you some direction. Codes can be pulled manually by using the diagnostic connector or a scanner.


Could be o2 sensor, bad spark plugs, rich idle(too much gas), bad spark plug wires, bad injectors, bad ignition coil/cap/rotor(weak spark), bad catalytic converter/clogged muffler, exhaust leak, etc.

edit: check the vacuum lines to

[coolusername]

so it came up with high NO and CO readings but no missfire.

ignition or timing problem??

[FORZA MILAN0]

Originally Posted by coolusername

so it came up with high NO and CO readings but no missfire.

ignition or timing problem??

Possibly... have you checked the car out yet?

[coolusername]

nope. not yet i think i'm gonna go see it sometime soon though.

[FORZA MILAN0]

Originally Posted by coolusername

nope. not yet i think i'm gonna go see it sometime soon though.

question ... Are you mechanically inclined?

[coolusername]

yeah. i definitely like to work on cars.

only problem is i live in an apartment currently and i don't have much space.

why?

[FORZA MILAN0]

Originally Posted by coolusername

yeah. i definitely like to work on cars.

only problem is i live in an apartment currently and i don't have much space.

why?

Ok good. just wondering.

[FORZA MILAN0]

see if he has any results from the most recent smog.

[excelS13]

timing might be off.

[SharkMan]

Originally Posted by FORZA MILAN0

see if he has any results from the most recent smog.

+1 that would give you an idea of what your going to need to fix. Also have you seen the car in person? So do you plan on buying the car sometime soon or still feeling your way through.

[coolusername]

Originally Posted by SharkMan

+1 that would give you an idea of what your going to need to fix. Also have you seen the car in person? So do you plan on buying the car sometime soon or still feeling your way through.

I'm still feeling my way through. I might go see it this friday if i'm not busy. I'm hoping that it's just a cheap fix. if it is i'm gonna get more serious about making an offer.

i haven't seen the physical test yet, but he just told me it read high on CO and NO

do you think the timing chain might be getting all loose and is due to be replaced?

[FORZA MILAN0]

Originally Posted by coolusername

I'm still feeling my way through. I might go see it this friday if i'm not busy. I'm hoping that it's just a cheap fix. if it is i'm gonna get more serious about making an offer.

i haven't seen the physical test yet, but he just told me it read high on CO and NO

do you think the timing chain might be getting all loose and is due to be replaced?

possible but we wont know until you open it up.. even if it off by a degree or 2 it will fail.

offer him 15 see if he takes it.

[SharkMan]

Originally Posted by coolusername

I'm still feeling my way through. I might go see it this friday if i'm not busy. I'm hoping that it's just a cheap fix. if it is i'm gonna get more serious about making an offer.

i haven't seen the physical test yet, but he just told me it read high on CO and NO

do you think the timing chain might be getting all loose and is due to be replaced?

To be honest bro, the only way your going to know what's going on with the car are what its going to take to get it to pass is going down there and diagnosing it yourself and checking the paperwork from the failed smog. If your serious about picking up this car you should go down there with the necessary tools to remove the plugs/check compression/check timing etc.