50SEVEN

Hey all, I've got an issue with my 1984 Z31 50AE. The engine runs ruff, I knew this when I bought the car and didn't care since I plan on at least rebuilding the VG30 that's in there if not a VG33. Anyway, I'm not sure what the exact cause of the roughness is, and I want to get it fixed so I can enjoy the car over the summer before working on the engine.
Originally I was told by the PO that it was improper timing, however since looking into it I'm starting to think otherwise. Here are the symptoms:
-Rough at idle and higher RPMs. (Gauge cluster doesn't work so I'm not sure on exact RPM ranges)
-White smoke, faint at first but when revving it begins to become thicker. At some times it appears faintly blue, but it's hard to really call it "blue" due to the lighting in the garage.
-Runs rich. There is a strong scent of gasoline with the smoke. Not like a leak, but as though it's not all burning.

One issue is that since there's no exhaust after the Turbo, the smoke spreads out from under the car, so I can't get a good concentrated look at it.
I'll post a video of the car running, possibly tomorrow. I'll also look into what codes are being thrown.

Any possible ideas on what may be the issue? I just don't want to spend the money for all the gaskets and new head bolts to do a proper head gasket job, mainly because I plan on rebuilding it in the fall.

86tcoupe

no exhaust from turbo back ...so no working O2 sensors , no wonder it runs ruff
if you are burning oil with out a converter you will smell it for sure, so maybe just a too rich condition .
a cold compression test would be a good start , be careful not to drop anything down the sp holes . and check the SP condition .

50SEVEN

Already ahead of you, bought compression tester today. I wonder'd about the O2 sensor being a cause, but not in that way. Is there a way to run this smoothly without the O2? I

don't have the funds for the 3" exhaust I want to put in just yet. The car needs tires, shocks/struts, and a few other things. The exhaust is planned for the Fall.

86tcoupe

1st question no...likely you need imput to the FI ECU
later cars had a fail safe mode ,but surge badly

I would resist going 3" back its already 2.5 or maybe you are saying you got it with out exhaust?
my 86 Turbo would start to sizzle the LR innner sidewall of the tire ,after some hard driving .
I replace the stock muffler with a $30 straight thru cherry bomb style and what a big difference. dropped 3-5 mpg too. seems more noticable improvement on the low end .

50SEVEN

I bought the car with no exhaust. And I figured since it was the turbo, a 3" would work well. In any case, all that is the least of my worries. While trying make the video for you, my turbo bearing when and started chirping. At this point I'm just going to leave it off the road until I put the VG33 in there, and I guess now I need a new turbo. Was planning on holding off on that until next fall, but hey, TURBO UPGRADE!

50SEVEN

Actually, what I'm wondering now is if the turbo failing was what was causing the smoke. I know that's one possible cause of smoke, and being that it was in my garage I couldn't get too great of a look at the colour. If that's the case, then no new head gasket is needed, which is great. However it means I need to find the cause of the rough engine, which could easily be from not having an O2 sensor. I'll try doing a compression test to make sure it's not a leaking gasket or worn cylinder, but I'll also take a look and see what codes are being thrown.