I have a VX
 

Hi hi have a 1994 vx with a little problem i pulled the spark plugs today and found that cylinder 4 spark plug looked like it was running very lean but i figured it was because of lean burn and such then i pulled the rest of the plugs they were all showing signs of runnining rich any ideas on what could be causing this problem?

i thought it might be injectors but it would be weird since 3 cylinders have that problem

could oxygen sensor be causing this problem

Please any ideas or suggestions will help me it doesnt seem like i am getting the mpgs i should be gettin

thanks

Stuck/clogged injector on #4 maybe

If you have a fuel problem that is only with one cylender why wouldn't it be that one injector? an easy way to tell is to swap injectors and see if the problem moves.

But then why would the others be showing sighns of burning rich

Because the O2 sensor sniffs the oxides from the lean cylinder and ECU richens the mixture. Also they'll look rich anyway in winter driving with a lot of sub 30 minute trips.

Was the plug melted/worn down?

Or was it just discolored?

Does your car smoke at all or take any oil?

I suspect it could be a clogged injector.