rojoe31

Hi, I'm sorry if this has been answered before. I wasn't able to find it. i got a 1992 300 zx n/a with 84000 miles on it. the car had an idling problem when i bought it from my friend and he said it was a vacuum leak somewhere and he wasn't able to find it. i tried to look for it but couldn't find it. not that its getting colder its gotten worse. Today after getting off work in the morning i start my car and it starts to idle very low. i stepped on the breaks a few times and the car nearly stalled out. i got back to the house and i checked the vacuum line going to the breaks and that wasn't it, it was still running rough. i don't know what it could be. I'm thinking there is a clogged vacuum line somewhere may be the pcv valve or so. Someone told me to run sea foam through it and it would clean it up. i really don't want to do that at least not till i check all the other options first. This is my first Z and i need help please. Has anyone else ever come across the same problem before? thank you very much.

napoleonzheking

NA or TT? Sea foam never hurts...

Hitting the brakes is weird... Considering on the Z32 they are vacuum operated via the BMC first and foremost....

Answer NA or TT first off; TT you will have several vacuums lines to sort through (especially if none of the MISC bull crap has been eliminated).

check the FSM (factory service manual, carfiche.com should have a Z32 maybe not year specific but all the vacuum stuff should be the same except the '96) there is a specific trouble shoot write up in the EF & EC section for weird idles that will give you specific things to check to start off with.

*edit* lucky you, my hard copy FSM was in my garage not at the shop so I was able to check a few pages for you (I don't read electronic copies because I have a hard copy, perks of the job, much easier to sort through), is the engine Hot or Cold, I presume (not assume) that it's cold because you said when you come outside in the morning after work, but we all know these things don't cool off easily, i'd start with pages EF & EC 85 and 87 (engine stalls when hot / cold).

as always start with the basics, check EFI harness connections for corrosion, make sure no fuel lines are leaking / crimped where you aren't getting fuel. Remember, any vehicle needs 3 things to run properly, fuel, air, and spark, eliminate them one bye one until you determine the general area of your problem.

rojoe31

well i looked at the FSC and i looked around in the engine a little more. i found the break master cylinder leaking a little. took it to a local mechanic to ask for an advise as well. he checked the vac. line and said all the lines checked fine but the leak from the break master cylinder could be the problem he said my boost could be bad too so i have to take a look when i take it off. Because the break master cylinder leaking it could be drawing more from the system. Does that sound right or am i just way out of the park on this one.

napoleonzheking

I'll presume TT since you said boost. Do you have an air compressor or access to one?
Do a boost leak check (you can make your own tester or purchase one http://czp.us/Cart/description.php?I...099.93.139.153 I made my own to customize it a little more), remember don't run more than 5 PSI through the system to prevent damage. this should help you find any vacuum leaks you have and is your best bet. I always have a squirt bottle with a little soap in it to help find them (keep it away from electrical connections)