Hi! I'm a new guy! Having a problem with my 280Z running on 5 cylinders. It doesn't appear to be a spark problem, since I changed out the cap and rotor, new plugs and wires as well. I've removed the valve cover to discover that my oil smells pretty strongly of fuel. Obvious sign of a misfire. Also, I've heard a little backfiring a few times. Does anyone have any clues to help me get this thing running right again? Think it's time for a compression test?

 

Welcome to ZDriver!

Leaky injector? Clogged injector?

 

I'll look into that one. There is fuel getting into the cylinder you can spell it on the plug because it doesn't seem to be burning. Where can I get one good injector for cheap though? lol I gonna start my project this weekend and I don;t wanna spend too much money on this motor at all. I only need it to drive the car short distances until it's ready for the swap.
Is there a way to really test that without replacing it?

 

I'd also like to add... There is a LOT of smoke coming from that little breather on the valve cover. The on that hooks back around to the intake piping.

 

That hose should be going to the throttle body. You might want to check that out

 

It is there, there's really only one spot for it, but I unplugged it to check out what's going on. And if I'm not mistaken that nothing but a recirculated beather. So that much smoke just can't be normal.

 

noooo, from the valve cover it connects back to the rubber intake boot. as for it smoking a lot and a fuel smell when you open the VALVE cover, sounds like a very odd issue. did you do a compression check on the motor? i say possibly a valve not seating. But if the plug smells like fuel then fuel is most likely getting to it, i'd say make sure that specific plug is getting spark to just to be safe. start the car with that dead cylinders spark plug boot not attached and wearing a glove so you don't shock yourself hold it near the valve cover and see if a spark grounds from it. if so you got fuel and spark. then perhaps look into timing. but also check the compression on it.

 

I used the spark tester, spark is getting there. I'm gonna do a compression test, then retime it if needed.

 

The only way fuel can get in the oil is past the rings. You may have an injector stuck open or the unburned fuel is washing past the rings. Bad rings would also cause the smoking. Do a basic comp check by putting your thumb over the spark lug hole and cranking it over. Make sure you are getting spark to the plug tip. Like I always say get your girl friend involved by holding the plug by the threads while you crank it/her over.

 

Yep! Another problem! Not It starts, runs well for about 2 minutes, then shuts off. And won't turn back on till I unhook the battery then plug it is... And then it does the same thing

 

Have you tested your alternator and battery? Cars do weird things when the voltage is higher/lower than it should be.

Also... is your fuel pump still running when it dies? How much gas is in the tank?

 

Alternator is good, tried two of them, and battery good and hooked up to a jumper. It's weird, it shuts off instantly instead of just sputtering out like fuel starvation. Like an immobilizer on a newer car. Fuel pump does still run...a matter of fact sometimes it runs when the key is out of the car. lol But that's a different problem. And the tank is next to full.

 

that is a weird problem. i would say check for spark and fuel delivery again. maybe your battery cables are old and worn providing the improper ground resistance or voltage necessary to run. seeing as it is a 70's era 280 it isn't to fickle as compared to the later model with the crappy CHTS setup and such. i suspect that or a AFM issue honestly.

 

You were right I had a bad source telling me wassup
ThAnks.