HybridS130

Okay so recently all of the sudden my Z has been coming up with a few problems, first off,
*rough idle
*lack of power
*obvious miss heard through exhaust
Friend of mine says that it seems to be a vacuum leak but, I have checked most of the lines but, have not conducted a leak test.
second
*car refuses to warm up during driving to and from work now that it has become cold well, cold for us floridians, thermostat is relatively new.
so being that it doesn't want to warm up i have to set the idle higher because it idles lower at cold temps, but, on warm days when it does actually warm up idle is at 1000rpm instead of 750rpm

jfairladyz

How far is the drive? Could be a bad thermostat causing the no warm up. I've had em be bad straight out of the package so it's worth a look. Just pop out the thermostat and see if it's open. It should be closed if the cars not warmed up. As far as the other problems: Full time or just while the car is cold? If it's just while the car is cold I'd investigate the Air regulator. If it's a full time problem then you should start checking to make sure the timings straight. Other than that a little history on how the problem occured would help with diagnosis. Something as simple as a clogged air filter can cause those problems over time, we need to know if this happened over night or what.

HybridS130

the drive is long enough that the car should warm up fully, the thermostat is stuck open because when i bought the car it was like that until i replaced it and this is acting differently, air filter isn't clogged i have Cold Air.

jfairladyz

Oh yeah I wasn't saying it was the air filter. I'm just saying a little history on the problem would be nice so it's easier to help you with your problem. I'm just saying that would help eliminate some stuff so people aren't giving you all kinds of advice on stuff that's not even going to help you. By saying that yesterday it drove fine and then today it drove like crap you can eliminate A LOT of stuff.

The only thing really that would cause a car not to warm up over a period of time is the Themostat. THats it. Cold weather can make it take a little longer, but you're in Fla so I won't go there. As for the other stuff, only when cold or does your car do all that all the time?

HybridS130

The rough idle, lack of power, and miss is constant. Im thinking that a different range spark plug will help the motor run warmer.

jfairladyz

It doesn't work that way. Different range plugs help to control pre ignition or fouling. While that could help your other problems it most likely isn't going to affect your warm up problem. But if your motor was working fine with current plugs before then it shouldn't need a different range of plugs. What mods do you have done other than the cold air intake? Typically it takes something extreme like raising the cylinder pressures a good deal (either with C/R, turbo, or NOS) to warrant the need for a different range of plug. It only takes a couple minutes to check the thermostat and if it's fine then it's another couple of minutes to put it back in. BUt I really think that's what it is. Most cooling problems related to the engine itself (well all that I can think of) are overheating problems, not over cooling. There's also a chance that the thermostat is not neccessarily stuck open but just opening too early. You can test that theory with a pot of water on a stove.

Have you checked the plugs to see if they're causing your driveability issues? Shoot through your ignition components and check em out. You can check to see if all your injectors are firing with a flat head screwdriver too. Fast, easy, and free I've had to replace a few bad injector clips and had some just work their way off enough to break contact with the injector too. I've also had my battery leak acid on my #6 spark plug wire shorting it out and causing a misfire. So give a quick once over.

EatmyDust

if you here the miss in the pipe, pull an old time trick and stick a dollar to it and see if it sucks the bill to it and spits it back leaving a carbon ring, that would mean a burnt valve. may not be your problem, but takes only a secound.

RodMoyes

Sounds a lot like the symptoms I was having... Might want to take ten minutes and do the AFM rebuild. It may not fix it like it did mine, but it's an easy thing to do and might make a huge difference.

Rod.

HybridS130

I remember my dad teaching me that a long time ago and even since i do it with all my cars and friend's car on a regular basis when ever we're having problems, they're always like hey what are you doing. . . hehehe

EatmyDust

Cool drifter
sounds like your dad was one of those guys, that knew what they were doing.

HybridS130

UPDATE: Car fixed itself as usual, everytime something goes wrong with the car unless it's something that outright breaks the car fixes itself after awhile. Now warms up fine, idles fine, no puffs of smoke at high rpm's, no more miss.

Dorifto

^ Gotta love Datsun.

I figure if I let my Z sit on jackstands long enough, the clutch master cylinder will fix itself, the body will straighten out, and the rust will disappear from the passenger strut tower.

NismoZigma

Lol your lucky! I got a problem with my idle.... AGAIN! After the EGM prob, well I guess I'll replace it but now the damn thing wont even start. It just starts trying to start and the fan starts but than like after 3 seconds the car like dies. It doesnt even get fuel in the engine I think. Well IDK I gave up cause it was dark and it was cold and I was hungry! Maybe someone can give me some suggestions.

RodMoyes

I'm tellin' ya... Pull that AFM out and do the procedure. Make sure to clean the contacts for the wiring harness on the bottom. You may be surprised. It only takes like ten minutes. What do you have to loose? If the AFM is not working, Your car will start, sputter and die.

Rod.

NismoZigma

I did the whole AFM thing and installed it back and now it just wont even start. Before I did it at least it started but now it didnt even start! I checked everything and was seeing if I had done something wrong. UGHH I dont know.. NEED HELP!

RodMoyes

Did you plug it back in?

Rod.

WildmaN

LOL hey Rod I made that mistake, after I rebuilt the AFM and installed the new NGK plugs. I was tearing my hair out, trying to figure out what was wrong. I couldn't get my Z to idle no matter what I screwed with or adjusted, set. It wouldn't idle. Then I decided last Friday to swap out the AFM out of my '81. Because I knew the car ran like a dream. So I am ready to take out the AFM out of my '82, and then I see it was unplugged! DOh did I feel like a complete idiot! So I plugged it back in, and my Z went to high an idle, so I adjusted the air-fuel mixture screw, and kept him about 1000rpm. It was nice to take him to Carl's house, which is like 3 or 4 streets away. And he was impressed how my Z was running. Just have some more bugs to work out of him.

NismoZigma

Update! Well it turns out that the hose that leads to the engine from the AFM was disconnected at the engine part! I couldnt see it last night cause it was so damn dark. Well after that it was still idling poorly. The AFM did get it to work a wee bit better but I think its going to take a little bit more than that. I just bought a fuel filter today and hope to get that in tomorrow (depending how I feel since I gotta cold). Oh yea I still got one problem though besides the idle. Now my brakes are crapping out! I bought some DOT 3 brake fluid cause it was almost dry but the brakes are the same. I gotta press em all the way down to even get any bit of stoppage. Oh well need more help guys so help me out!

duowing

If you're brake fluid was about dry you prolly got a leak somewhere. Even over time and after getting the air out of the system, brake fluid I can't imagine would really run out. Or it would take a long *** time. Generally when you're pressing them to the floor you've got a line leak somewhere cus you're losing pressure.

RodMoyes

It's most likely a master cylinder failure (at least that's the most common reason for your symptom). Just the same though, check around all the brake line fittings and the calipers to see if any of them are wet or appear to have been wet recently.

Rod.

NismoZigma

Thanks for the help. When I press the brakes it sounds wierd like theres no pressure but its still hitting something. I did bleed the brakes about 2 months ago but the brakes werent working that good before. Im guessing its the master cylinder than. I want to check it right now but I gotta freakin cold so I cant do anything! Oh well I'll get to it as soon as I can. Again thanks for the help.

jfairladyz

Crappy Idle - Probably a vacuum leak. Check all them hoses.

Bad brakes - Take Rods advice and replace the BMC. IT could be the source of your leak if fluid is seeping past the plunger. So in essence, it would be a leak and a bad BMC in one. It is indeed not likely for brake fluid to just evaporate.

NismoZigma

Well this is why I love this car.... they seem to have mutant powers and basically fix themselves! The brake problem is gone. I got the caliper cylinder and just re-tightened it, went for a drive and than it was feeling great.. so I guess brakes are fine now. As for the idling problem, well went to the junkyard yesterday initially going in looking for the caliper as a precaution and was about to leave since they didnt have one. Well get in the car try to start it up and the battery died!!! Well thankfully I just went back to the yard, got a battery, put it on. First crank the thing turned on and idled great. It was back to around 900-1000. So my idle problem is technically gone! Nissan really did make a great piece of machinery here.

91Zman

hm, thats odd my car idles high when its cold

RodMoyes

That's a good thing. It means your Cold Start Valve is working. It should idle high on a cold start for anywhere from a few seconds to a minute or so.

Rod.