let me make it easier

[Sdavne]

Ok so I know my posts are confusing so let me try this. If your car was turning off while idling what things would you check, already changed alternator and battery

[rally510]

fuel filter would be one thing to check.

[nissanfreak12]

Engine codes, go from there. If nothing, check fuel pressure, spark, compression, and vacuum leaks.

How long has this been doing this? Possible IAC, it has an adjustment screw, could be in too far or the whole IAC may be bad. IAC=Idle Air Control, key word Idle

[Sdavne]

NO codes, i am going to compression test it this weekend and check the fuel system (fuel filter pump ext..) but i am not sure if has anything to do with iac or tps because when the car first starts it runs high around 1100 rpms, so that will be one of the last things i will change, but does anyone know how to check fuel pressure?

[nissanfreak12]

Fuel pressure gauge, plumb it after the filter before the rail, start the car, check at idle and higher rpm's. Also check it after taking off the vacuum line on the FPR, it should rise. My numbers may be off but I think 34ish psi with vacuum on FPR, and 39psi after taking it off.

Both TPS and IAC have a lot to do with why it idles high at 1100rpms. If the TPS is not adjusted right, not only can it make it die, it will idle high, I think its set at .40. I had pitstop in phx adjust it to .35 and it idled to about 1500rpm, the min I moved it to .40 the idle dropped to over 1000, the higher I set it the lower it got till after I think .5, it just ran odd. After adjusting it run the car and unplug the TPS with the car running to let the comp "learn" the adjustment.

The IAC controls the idle, these should be the first things you check after fuel pressure. How are the vacuum lines? High idle can also be caused by vacuum leaks, so will bouncy idle, so on so forth.

I am not saying to replace them, just test them, testing is easy and free as long as you have a multi-meter. Its never a good idea just throwing parts at it, it will get expensive fast, and may not even fix the issue.

How many miles are on the car? Any major work done to it?

[GerryO]

NO codes, i am going to compression test it this weekend and check the fuel system (fuel filter pump ext..) but i am not sure if has anything to do with iac or tps because when the car first starts it runs high around 1100 rpms, so that will be one of the last things i will change, but does anyone know how to check fuel pressure?

1100 rpms doesn't sound high for a cold start engine idle speed. Setting the idle speed involves a combination of things. Engine timing, clean throttle bodies that always close fully, throttle and cruise control cable tension, TPS output voltage, engine temperature, Air Regulator/IAC functionality, accessory load on the engine (PS/AC/Alternator), MAF cleanliness, vacuum leaks and finally the idle speed screw adjustment.

[Sdavne]

Just an update, did not have much time to work on past weekend. just checked for vacuum leaks and spark plugs. One thing I noted was the belt on altanator was missing some teeth and I want to replace the belt could that cause the car to stall, and also is there an easier way to cheage the belt because when I loosen the tentionar you can only pivot the altanator about a half an inch, or do I just have to play with the belt to get it off.

[nissanfreak12]

Did you loosen the main bolt holding on the alternator? You should be able to pivot the alt quite a bit. It could cause the car to stall mainly under heavy load, but its a stretch. The belt would have to be very loose for it not turn the alt. Why wasn't the belt changed/check the the alt was replaced?

[Sdavne]

Yeah the bot
ltd was off and because I did it at my work warehouse and I ordered the alt and forgot about the belt and it was late and the parts store was closed

[Ace2cool]

Ok so I know my posts are confusing so let me try this. If your car was turning off while idling what things would you check, already changed alternator and battery

Back to the top. Is it an abrupt shut off, or does it sputter to a stop? Abrupt, I would look at the PTU, MAF, and CAS. Sputtering, look at the IACV, fuel pressure, and vacuum leaks.

[Sdavne]

It sputters and than shuts off, it does it more when under a heavy load (raids head lights fan defrosters) when it sputters the rpms drop lower and lower. how do I check the fuel pressure? Where is the nipple?

[GerryO]

It sputters and than shuts off, it does it more when under a heavy load (raids head lights fan defrosters) when it sputters the rpms drop lower and lower. how do I check the fuel pressure? Where is the nipple?

Engine idle speed should cycle up and down a slight amount, as the alternator cycles ON and OFF, changing the mechanical load on the engine.

With the battery fully charged, have you tried starting the engine and letting the car idle with the alternator disconnected? AC and PS (front wheels not pointed straight) will also increase the mechanical load on the engine.

How old are the spark plugs and are they OEM?

When were the battery terminals and the insides of the cable connectors last stainless steel wire brushed, re-attached and coated with a shot of WD40?

[Sdavne]

I recently changed my spark plugs about 3 months ago with bosh plugs, the car is tuned for colder plugs, and I do not remember what exact plugsshouod be in the car, I will do some research and also look for my paper with all the specks on it and recharge them, I forgot about that all together, and I changed the negative cable about a month ago but not the positive, I will also change that this weekend, how far does the positive cable run? And where does it run to?

[Ace2cool]

There's no nipple to test fuel pressure on the Z32 like on American vehicles. You have to get an inline gauge, relieve pressure on the system, and then hook the gauge up inline with the fuel lines (usually just after the fuel filter.) Then crank the engine and see what happens.