Troubleshooting????

[240booster]

I got a few little things wrong with my car and i wanna c if i can fix them b4 i take it to a shop and pay out the ass to have it done. First, i think my mixture is running rich, it kinda pops when i push the clutch in and let the engine decelerate, and my exhaust tip is black on the inside. Next, my check engine light is still on from when i cut the wrong wire trying to kill the speed limiter. Also, if i run the car at high speeds for a little while then i push the clutch in and let it idle down, it idles wayyyyy down to like 100 rpms then bounces up and down until it finally smooths out, the problem is that it has idled to far down and the car has died on me 2 or 3 times while i was going around a curve so then i had no steering or brakes and i had to crank the car again quickly to get around the curve. Finally, I think my alternator is going out cause when my bass hits on my system i can actually watch my rpms drop from the juice it's pulling, and i only have a low line 12 in. sub with a 200w amp. that shouldn't affect the engine that much. Maybe, this problem is connected to the previous one?? Any feed back is welcome THANKS GUYS!!!!

[geeaj]

Check MAFS. This can cause your car to run rich if it is going bad. I would start by cleaning the connector and running a new ground if the voltage does not check out. Refer to FSM for specs.

Another thing to check is the water temp sensor. My car started running rich and had idling problems when the sensor was going bad. Not sure about the DOHC, but on the SOHC, its located on the intake manifold, adjacent to the temperature sensor that sends a signal to your temperature gauge.

Second, I would check your TPS. Clean the connectors and then check the voltage as per FSM.

Definately sounds like  your alternator is going out. I would address that first. It sucks to be driving and then all of a sudden your lights dim and all your accessories die out.

[NoTuchn]

except for the alternator thing, my car has the same idling problems. running rich, and idleing inconsistantly and low.  

thanks for the advice geeaj.

anyone else have any ideas?

[chickenmanq]

Take it to the Nissan dealer and see what codes pull up regardless of whether or not the check engine light is on.  To check your computer codes should only cost 30-50 bucks depending on the dealership.  Just make sure you give the impression that you know what you're doing, or they might try to dick ya.

Once you get the printout of what's wrong, fix it, tell them you're going to fix it, can you bring it back in to double check everything went ok.  9 times out of 10, they'll waive an additional fee for checking the ECU again when you bring it back.

Oh yeah, solder that wire on the tranny back together if you haven't already.

By the way, the battery disconnect for 15 minutes sometimes clears the ECU, but sometimes it doesn't work, and you have to have the guys at Nissan tell the ECU via their computer that it doesn't need to pay attention to whatever faulty signal there was.

[nos240]

i think the idling problem could be cause by a IACV also known as air regulator or the IAA unit (not exactly sure what it does, but i think it work in conjunction with the iacv). both of this unit are located on the intake manifold next to the firewall. it's a little hard to find. it's controlled by the ECM that allows air to bypass the throttle body into the intake manifold during idle. it keeps the engine from starvation of air. i think after a while, the valve inside the iacv get stuck from carbon build up in the intake manifold, causing it from moving freely. if im not mistaken, does your car sometime has the same problem during start up also? if so, then the iacv could be the problem. one other thing, how did you know that your car was running rich? do you have a air fuel ratio meter? i thought exhaust tip are suppose to be black on the inside.

[240booster]

ok well i don't have a FSM, and i don't know what half those abbreviations r. i know MAFS and ECU. Neway, I just installed a CAI couple months ago. and the MAFS looked good, don't know how to check if it's working or not though. Is there neway to check the alternator while it's in the car??
Plus, i did unplug the battery for about 4 hours one day about a month ago and all it did was fuck up the channels on my radio.
Finally, my car does not do the idle fluxuation when i crank up it's only when i have been running the car for a while or at high speeds then i suddenly let it idle down to normal. And i just figured my mixure was off cause it kinda pops and gurgles when i idle down ...... i figured that was excess fuel burning off thus rich mixture, plus the black tip.