My Z is Sick, i need help quick!!!

[S130Z]

Well the car has been running fairly well lately (I had a fairly decent vacume leak that I took care of). But if I run the car at a consistant RPM for 10 minutes or more and then turn the car off, when I turn it back on and start going the car missfires really bad for about 2-3 minutes and then its fine.

[naviathan]

Detonation from heat soak in the cylinders or fuel lines just starting to vapor lock. AAR could be cooling down while shut off and the 2-3 minutes is a vacuum leak from the valve opening. Leaking injectors flooding cylinder while shut down. I could go on for a while with possibilities, but you'll have to give us some more info to go on.

[S130Z]

It very well could be heat soak because I am running an N42 intake with no heat shield. I am also running oversized injectors and am running slightly rich. I am not running any cold start system so I dont think it could be the AAR.

Could advancing my timing help out with running rich or would that not do anything?

[Hyuri]

Have you checked all your sensors? Download the '83 FSM from xenons130.com and get a multimeter, pretty much all the sensor tests are continuity/resistance. Takes no more than an hour or two to check everything, and it'll completely eliminate the electrical system as a possibility. You can do a quick-n-dirty check at the sensors, but that won't tell you if there's a wiring problem. Do it properly and plug the meter in at the ECU plug.

 

If you find a faulty sensor circuit, first check the sensor itself to eliminate a wiring fault. If the sensor fails, clean the sensor contacts (needle file, emery board, etc.) then check again. If that doesn't do it, try cleaning the other end of the sensor (fine sandpaper, contact cleaner, etc.). If cleaning just doesn't fix it, take your multimeter and the resistance specs with you when you pick up the replacement to make sure you don't get a dud.

[Zeero]

WOW. I am glad this thread has started. Everyone has given great responses and possible problems. I have just recently had the exact same symptoms with my 82 zx turbo. I just filled the tank and when I left the station I gave it WOT into 2nd gear. Now it idles very rough and at cruise it stutters. I still have the same power but it is quite smelly now and it backfired a couple times.

 

 

1982 turbo. No cat, EGR pinched off, everything else is pretty much stock. I know I need plugs soon anyway, so here is hoping that is the problem!

[Kanzen]

Lucky I found this thread when I did otherwise I'd proberbly do something stupid and regret it.

I do not have a 280ZX Turbo engine, I have (What Im lead to believe) is a 280Z engine transplanted into a '71 240z though even that Im not sure of, I have many pictures of the engine for reference, has P90 heads, N41 intake (or was that E46...) but I am suffering similar if not identical symptoms from what has been conversed in this thread.

 

Im not a professional, I am learning and taking whats been said already, on board.

 

When turning the engine over, again it idles very rough, if not cuts out, if I etch it on with a bit of throttle, after about a minute or two of "warming" the engine up, it still backfires (sounds more like its choking/coughing then backfiring) but idles fine. There is a large sump of oil located towards the front of the engine, I have pictures to show you what Im talking about.

 

At first I thought it could be too much oil flooding the engine out, there is a very rich smell of petrol/oil/something whenever the engine is running, then I thought it could just be running rich, after checking the spark plugs, the tips varied from a dry sooty residue to a rather oily residue - reading up on in this in my reference books basically says : your running rich, something wrong with gasket, replace plugs, air filter, drain oil and tune.

 

Sound right?

 

Even if its an excessive amount of buildup, would a product like Seafoam help "clean" out the innerds or is it best to rip the engine apart and see whats going on with your own eyes?

 

The gentleman who I bought this car off had it serviced not too long ago...which is what I thought was weird.

 

I understand the OP has higher priority, and considering the intricate nature of the Turbo models, deserves more attention, Im just bleeding my heart out.

 

Again I do not have a turbo/ZX engine so Im not sure if the exact tests mentioned earlier will be valid for my engine, though I will try anything.

Pictures :

[Zeero]

Well, upon examination during daylight hours I found out that I blew off 3 vacuum plugs/lines! Repaired the damage and all is well again! Good luck to the others who are having issues!

[bakerzxt]

i have had similar problems with three different solutions on my 83 zx turbo.

 

the first one i was getting evrytime it rained my car would not want to idle or dive at low rpms but would smooth out at high rpms and after awhile i figured out that i was getting condensation under my dizzy cap and this cause my car to run really bad until it was dry.

 

the second time this happened my car would not idle good at all and would sputter and backfire in the intake and exhaust until 3000rpms then it always smoothed out and i found out that it was my air filter that was completly clogged up and that was causing it to run so poorly.

 

and the third time it was more of the same thing that it would idle and i found out that it was just my timing was off about 20 degrees.