Idle questions

[Jioz32]

Hello I have a 94, N/a & I just had 2 questions
First, what is the base idle rpms for my car if anybody knows?
Second, when I start my Z at a cold start it'll start then die out. It has a good battery, starter, & new alternator. I have to hold my foot on the throttle for a few second then it won't die out & idle, But when it idles cold The rpms it idles at are about 200-300 rpms, when the car is running warmed up the rpms are at a normal level between 800-900 idk what to diagnose it as & when the car is warm are my rpms too high?

[DCaff300ZX]

Welcome!
Almost any Z32 problem can be diagnosed and tested using the online service manual located in the "Everything you need to know...Z32" sticky at the top of the page.
Base idle setting (with IACV connector removed) is 650 +/-, basically as low as it will idle itself in that range. When you re-attach the connector the idle should ramp up then settle at the correct idle from there unless there are corrosion issues (extremely common throughout the engine bay) which can cause a myriad of issues, all of which you can test and track with the osm.
Also, LOTS of posts on this subject so a search WILL help as well, Good Luck!

[Ace2cool]

Sounds a lot like what my N/A was doing after an injector replacement. Never tracked the issue down, cause it kinda just stopped doing it (I know that's not what you wanna hear, lol). It really sounded/felt like a vacuum leak when it happened on mine though. Doubt it would be the IACV cause that adds air to the system in a metered fashion, so unless there's a cracked hose to the IACV, you're probably good there.

Other things to do would be check ECU codes. MAF issues can cause that kind of problem. Clean your connector and make sure you're not throwing a MAF code.

[DCaff300ZX]

Sounds a lot like what my N/A was doing after an injector replacement. Never tracked the issue down, cause it kinda just stopped doing it (I know that's not what you wanna hear, lol). It really sounded/felt like a vacuum leak when it happened on mine though. Doubt it would be the IACV cause that adds air to the system in a metered fashion, so unless there's a cracked hose to the IACV, you're probably good there.

Other things to do would be check ECU codes. MAF issues can cause that kind of problem. Clean your connector and make sure you're not throwing a MAF code.

Damn, forgot the second part about the idle issue...thanks for catching that, Ace!
I agree that the IACV may not be an issue unless the cold idle valve is stuck as mine was, WD-40 squirts into the IACV seemed to cure my similar issue somewhat, but like Ace mine more or less went away the more things I fixed. I had a cracked hardpipe nipple that I replaced (hardpipe) and a few other things like CTS connector and as you are looking at, base idle adjustments. At that point my injectors got into the mix and 2 got replaced along with the harness connectors, and really that was about the end of my weak cold idle issues, until the engine gave up years ago.
I suggest a full service of the idle system using the fsm for the what's and where's, if you are not already up on those areas and items. Green corrosion and cracked/weathered parts are your enemy, be sure to check and clean all connectors and replace any that are cracked/broken as they will allow corrosion, if they aren't already among the ones that have no corrosion protection.
Good Luck!