Still Having Problems with my 240Sx...

[BreedOfSpawn]

2 weeks ago i bought a 93 Nissan 240Sx stock... and shortly after purchasing it I noticed it was shutting off...

For the last few days i had no problems with the car and drove it relitivly well and long... Just today i took it out for a ride after it sat in my driveway for about 18 hours unused started fine me and a friend took it out for a 2 hour drive drove well the whole time... afterwards on the way back i stopped off at a friends house for a few hours to hang out and when i got back into my car it started and stopped three times...

Finally i managed to get the engine going... but once i got out of his street i was going from 2nd gear to neutral, i stepped on the clutch and pressed the break to stop it at the stop sign and the car stopped again just shut right off... it did this about 10 times on the way home... i live 5 minute drive from my friends... It seemed to just want to stop for no reason...

Someone tell me whats going on and how much I need to fix this problem because i just bought the car after selling my old one and its starting to scare me a little bit.

Thank you in advance.

[vancouverbc]

I assume you have cleaned iacv and made sure both solenoids are working.

I would then check for rust on the air filter or anywhere in that area. You should disconnect the aiv(air injection valve) hose that connects to air filter.the aiv is taking air from the air filter and injects it into combustion . when the aiv is old it starts allowing exhaust gas/water into air filter area which will cause a ton of problems. it is well established that the aiv valve is useless so it is fine to disconnect it. you only have to disconnect the hose that goes to air filter. plug the hole in the air filter housing.

this thread addresses the aiv issuehttp://forums.nicoclub.com/zerothread?id=124117

[vancouverbc]

This pic depicts what needs to be done. You only have to disconnect one hose at the air filter housing.

[vancouverbc]

check your ground:

zerothread/159907

also, unplug your o2 sensor and see if that improves the situation

[BreedOfSpawn]

Thanks for all the advice VancouverBC I'll check those things out first thing in the morning its now 3am and I should definetly get some sleep but thanks on the fast replies as always.

[BreedOfSpawn]

Alright here's the scoop... I drove the car again during the day it runs fine...

At night when i turn the lights on I see my idling jump from 700rpm to 500rpm and back up to 600 then back to 500 then back to 700 all while the car is in neutral with nothing happening to it...

During the day the idle still jumps around but not as statically as it does when the lights are on at night.

So anyways when i drive the initial take off is fine but once i come to a stop light and i downshift and work my way to 2nd gear... hit the clutch and break to bring the car to a stop at the light the car shuts off i see the rpms go from 2000 to 1500 to 1000 to 500 to 300 then ultimatly at 0 as the car shuts off... its almost setup perfectly to the point where i know if im using some of the juice in the car then it will shut off at every stop...

I've come to the conclusion that maybe the alternater, the timing or the voltage regulator are not functioning propperly it could be either 1 or 2 outta 3 or worst case senario 3 outta 3... So tomorrow im taking it to the shop to get a computer diagnostics scan done to it and also have the alternater tested.

Im still a n00b first time driving a standard car and deff first time experience with a nissan... Still own my old 98 Tiburon *scoffs*... automatic lol so if anyone has any recogmendations for me to also check out ill definetly bring them up when i speak to the mechanic thank you all for your help thus far.

[vancouverbc]

I think the computer tells the iacv to to increase idle when lights are on. If you had a bad alternator, your battery would be dead and you wouldnt be able to start car. Stalling when you put clutch in during turn or when you come to a stop sign happens to almost all 240sx's. I'm pretty sure a working iacv will compensate for any electrical problems to bring idle up so you dont stall.

Maybe I dont understand your problem because most people leave their foot a little on the gas when they come to a stop sign to solve this problem.

[BreedOfSpawn]

Going right now to get the IACV checked out , I think your right about the alternater being fine I ran the test on it this morning came out working fine the Voltage Regulator i need to still check but im gonna get it looked at really quickly.

[BreedOfSpawn]

Got the car back she works... The computer came up showing something was wrong with the AAC... So they cleaned it all out the idling is now standing still at about 750rpm to 650rpm... I still cant help but wonder if it will go bad again soon...

[vancouverbc]

The AAC is the valve that gets dirty. It needed to be done regardless.The AAC is the main valve of the iacv.

[BreedOfSpawn]

Hehe... Well I shoulda just cleaned it myself rather then blowing money... but oh well... Next time ill know better, Vancouver could you get me a picture of the AAC valve btw and proceedures on how to clean it? so I could just always do it myself if it starts to get funky on me again. Dont stress if you cant its not that important im sure ill figure it out eventually.

[vancouverbc]

You likely wont have to clean it again. I took the epoxy off the large brass screw and removed screw, piston and spring. You only need a Q-tip and carb cleaner. Once you have the unit out it is very apparent what to do. Very simple mechanism.

Older cars really are not cost effective unless you do the repairs yourself.

The large brass screw is right above the idle adjustment screw as show in the attached pic. The brass screw looks beat up because i had to drill and chisel the epoxy off. Use a mirror or a camera if you have hard time seeing it.

Modified by vancouverbc at 2:06 AM 7/7/2006
Modified by vancouverbc at 2:06 AM 7/7/2006

[BreedOfSpawn]

Thank you very much VancouverBc You have been such a great help and the car is running quite well... Actually better then it ever has in my possession I dont wanna leave it just keep driving it 24/7 lol but the premium gass is too much now.

But Thank you.

[vancouverbc]

Good stuff:) You're welcome.