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View Full Version : fuel not being burnt in only 1 cylinder!? how can it be


kroos268
03-12-2010, 04:50 PM
1996 KA24DE

there is lots of white-ish smoke coming out of the exhaust. I saw some moisture, and because cylnder4 is expells dense vapor when the plug is removed, I think the fuel is not being burnt. At first, sparkplug4 was major black. But now, he doesn't turn black anymore. When I unplug the fuel injector#4, nothing happens. BUT when I unplug the others, 1-3, it makes engine shutter. So I am running on 3 cylinders obviously, #4 is not doing anything.

I dont know what to do.

Here's what I checked!

INJECTOR issue? three different injectors have visited this cylinder with good o-rings. the problem remains. I remove the fuel rail and turned key to 'on'. there are no leaks.

Compression? Nope, all cyl reads 150.

Spark? I swapped plugs in 3 and 4 with no impact. I put the timing light on cable4 and it registers 22 degrees on the timing marks. Often there are missing flashes only on this cylinder. This is suspicious! I removed distributor cap and dont see any issues with making contact.

Thanks!!
steve

j87w
03-12-2010, 08:04 PM
Are you sure injector 4 is gettting the correct injector pulse signal? Are you loosing any coolant?

kroos268
03-13-2010, 07:24 AM
I checked the injector signal with a multimeter because I dont have an O-scope to see duty cycle. All injectors, even#4, are showing 10.5-11.5 volts. If the voltage swing is 12v, then I'd suppose injectors are running at 80-90% duty cycle.

the smoke has only existed in my driveway; so I dont think I can see a noticeable coolant difference. Is it possible to pass compression test but still have coolant leak?