Electrical/Power Gremlin

[BallZee32]

Hello all. I'm new to this forum, matter fact this is my first post. glad to be here. I've been lurking on other forums, and this one seems to have the most knowledgeable/helpful people. now with that out of the way here is a little back round.
I'm new to the Z32, but not new to Z's the first car I bought was an 08Z33 when I was 19, after dumping 15+K worth of mods in it, I found myself at the age of 22, and thinking that money is more import.. so I sold my baby, and immediately regretted it. I just missed the car scene and life style, so the month after I sold my Z33 I went and bought an 09 G37s, although it was a gorgeous car, and fun to drive.. at the age of 22 it just felt to grown up , it was no Z that's for sure.

a couple years pass. I'm now 25, I've bought a house. and realized I am not happy unless I am spending my money on a hobby that I enjoy, I.E a car I can dump money into and say "I've made it that way" last month I acquired a 1990Z32 TT 5SP, bought it with about 54k original miles
for being 26 years old (older then me) it is a blast to drive. interior is a 8/10 and body I would say is a 6 to 7 outta 10. typical door dings paint chips for a 26 year old car. but there is zero rust which is great. a nice paint correction will bring the car back to life.

moving on to the issue at hand... I bought the car from an older guy in Illinois. about 5 hours from me, I live in Des Moines. when I picked it up and drove it home, it was strong AF, pulled very well. fast forward about 1200 miles, miles that I've added. I've developed a electrical gremlin that has made me say very bad words about nissan

for starters my dash lights are on while the car is running I.E the HICAS, BRAKE, LIGHTS, and windshield washer light, no CEL though. and stock vacuum/boost gauge doesn't work.
on cold starts the car will turn over fine, shoot up to about 1300RPM, drop to about 500RPM or below and have kinda a "lop idle" until the car is at operating temp, then the idle will be fine. if I rev the engine while it is cold and its doing that "lop idle" nonsense, it will rev fine, I let off the throttle and the RPM's will fall flat and the car will die... and i will restart it with out issue. if the car is warm it wont do that all the time, but on occasion if I rev it up, let off the gas, it will fall to about 500rmp act like it wants to die, then smooth out.

if I am driving around and put it in neutral the rpms will fall flat, I lose power... but if I pop it into a gear within say 2 to 3 secs of that, its like the car just starts again, and it will be fine. I have replaced the alternator less then 300 miles ago, I pretty much have all new vacuum lines. I still needa do the ones that are coming off the waste gate actuator, I've replaced the RH side PCV hose, still gotta do the others along with the values, I have the parts, I've just been so busy. I replaced the IACV hoses. I've sprayed all the connectors I could get to with dielectric cleaner.

here's the gremlin part... while the dash lights are on as mentioned above. it boosts fine. just crappy cold starts, and that stalling issue.
if the lil gremlin is away, and the dash lights are off which is rare now the car cold starts fine, and doesn't stall out at all.

any thoughts on what this issue could be?

[Sgt]

Welcome!

Your idle issues sound like your AAC/IACV & air regulator could have an issue. These 2 devices regulate idle air and air for cold starts. These are found on the back of the plenum. I would take them off and clean them. You can also test the solenoid on the iacv when you take it off by touching it to 12v and making sure that opens the valve inside.
https://z32.wikispaces.com/Idle+Control
I just cleaned mine while I have my engine out. I fully disassembled them to fully clean them. I would only bother going to this extent if they look like they are very dirty inside, otherwise use some wd40 to grtget things moving. The big spring in the iacv should be tight enough to just keep the valve closed. If it's loose, you'll have to scrape the expoxy off the set screw and tighten it just until the valve is seated closed, then re-epoxy. The smaller screw above it should such that the small hole on the inside is half covered.

Clean the electrical connectors with electrical contact cleaner while you are at it, then scrape them with a small screwdriver.

That should address the stalling and idle issues.

[BallZee32]

I will start there... what are the chances that its a MAF?
a little more detail... I changed the plugs, new coolant sensors, both to ECU, and to gauge, I know its running rich b/c I can smell fuel.

[Sgt]

The intake can cause the car to stall if you put the clutch in when the car is traveling down the road and you have a cold air intake that is exposed to wind blowing on it.

As far as the MAF itself, you can clearly the electrical contacts with electrical contact cleaner and scrape them and you can find a sensor cleaner for the element on the MAF itself. I kinda doubt it's the MAF tho.

[BallZee32]

so i haven't drove my car since sunday. haven't even started it. today i came home from work. got it her, started it b/c i wanted to go for a drive, i let her warm up like i always do, well when i started it, i noticed that i didn't have a rough idle.. and that my dash lights weren't on. it seems like the lil gremlin had left… well that was for the time being i started to drive it, and everything was going swell, pulling hard, would throw it in neutral, and she didn't want to die at all ^__^ i looked at my gas gage and noticed that i needed gas. i was at 1/4 of a tank, pulled into BP got gas. i get there gas b/c it does not contain ethanol. put $20 in. that got me to 3/4 of a tank. started it… and wouldn't ya know…. the lil gremlin is back, dash lights are on, but the idle was good because the car was warm. so here me out on my thought process, and don't flame me if i sound like a tard….

I'm thinking this nonsense has to do with something fuel related… if its the pump,injectors, FPR, fuel temp sensor, or something else, heres my reason for thinking that… this is the second time that i have noticed that the car runs great with no lights on when at 1/4 of a tank. and both times, i put gas in it, the lights come on, and thats when the stalling starts. also i smell gas a crap ton when its past a 1/4 . at idle it smells like its just dumping fuel. but when its at or below a 1/4 its really not that noticeable. I'm thinking with all that fuel in the tank, the injectors are just dumping fuel b/c it recognizes that it has more gas in the tank? also when i put it in neutral and it stalls, and i throw it in a gear real quick, it sounds like the pump/solenoid kicks back on, and suddenly its running fine. I'm thinking when i put it in neutral it cuts fuel to fast and isn't injecting any to keep the car running?

what are your guys thoughts?

[nissanfreak12]

Car only knows how much fuel it has by the gauge, doesn't run through the ECU. What it is doing is just a coincidence.

The solenoid you hear that kicks back on is probably the fuel pump and relay kicking back on, it will only run for a couple seconds when the key is in the on position then stop. If the car is running it is on continuously. What you hear is it shutting off because the car dies and you putting it in gear turns the engine so it kicks back on.

Lets get some more info;

Do you have any mods to the car? Stock air filter or installed a pop charger?
Have you tested the alternator? mainly when the lights are on, is it charging the battery when the lights are on?
Are you sure all the grounds are connected? Back of the alternator has a small ground, make sure it is tight and oil free.
Is the alternator clean of oil or ATF(power steering uses ATF)?
Are the connectors clean of green crud in them? Mainly CTS? Take the connectors off and look in them, if they have any corrosion in them, they need to be cleaned.

[BallZee32]

hmmm it is defiantly odd, and the alternator is brand new, I just replaced it. tested it 3 times on the tester at AutoZone when I bought it. I hooked everything up, including the ground. as far as the connections in Atop of the engine, I have sprayed every connection I can get to with dielectric cleaner. however, every connection is missing the metal clips that actually clip the connecter on. I have bought a couple new pigtails, and will slowly replace one at a time.

the car has upgraded turbos, FMIC, single pop charger, new 555 style injectors, or so I was told, I don't know how to verify if this is true or not?

[BallZee32]

update…
i seemed to have fixed the cold start idle issues, i clamped down all my vacuum lines with clamps, so seemed to be a vacuum leak. now onto the interesting thing, i noticed if i pump my brake pedal really rapid my rpms will drop, and the car will die..
could i have a vacuum leak in the brake booster itself?