Heya,

cross fire injection here, but not sure if it's just the wires or a bad plug.

The engine's running rough all of the sudden. Instead of just purring, it's more like it has a big cam (boom, boom, boom) like the choke's on, but I obviously have no choke. Just started. I changed the fuel filter, the K&N's are clean. I pulled two plugs, new last year, they're kind of black like the engine's running rich. I'm going to check the O2 sensor, but I'm wondering if this is the problem, my cat may be clogged? Also, it's happening all the time. Idle, step on it, run at 2500rpm, drive at 65mph, all the time. If I stomp on it on the freeway, I'm getting some smoke. Could be oil blowing by, but it's not loosing oil. I'm thinking it's running extremely rich. The distributor cap looked a little corroded, am I missing this simple point of a $10 fix?

Thanks !

Take a look at my response to your first post about the O2 sensor. But that does not sound like your problem. It is likely that one of the plugs are fouled and misfiring. This from your statement that they are getting black. A misfire will cause the fuel injection system to run rich, and blacken all the plugs. (see O2 sensor post) You could have a bad spark plug wire as well. A vacuum leak will also cause this problem, but the symptoms usually go away at high rpm and load. OR... it could be problem with you crossfire fuel injection. If the fuel pressure is too high or if an injector is leaking, it will cause it to run rich and that could foul a plug and lead to a misfire.
Check the ignition system first.

Ken Styer

Hey thanks for the quick reply. Hard thing, if one plug isn't fireing, how will I know which is bad? Should I just replace all wires? The plugs only have 3,000 miles on them. If it's a fouled plug, maybe that will be obvious enough.

Thanks !

|UPDATED|2/12/2004 3:29:10 PM (AZT)|/UPDATED|

On my 84 (cross-fire) i had similar porblems. Replace the coil but, go with GM only. The plugs are fouling because of the coil. They are real easy to replace, a cap and rotor are usually good to do at the same time

Yes it could be caused by a coil. And that could foul one plug, then the others. There can be other causes. If you use a test light with a point on it you can find the cylinder at fault. Connect the ground clip from the light to any good engine ground. Now go to the end of the plug wire by the distributor. Do NOT pierce the wires, but slide the point of the test light between the wire and the boot that attached to the cap. When it goes in far enough, it will short out the plug wire. If the engine changes, that one was fireing. When you hit the cylinder with the problem it won't make any difference. Follow the wire to the plug. Change that plug with another one in the engine. If the problem moves to the other cylinder, install a new plug. If the problem stays on that cylinder, swap two of the plug wires. If it changes, put in new wires. You should do the entire set, they all have the same wear on them. If the problem is still on the same cylinder, shut off the engine, pull the wire off the cap at the dead cylinder, and restart the engine. Hold the tip of the test light about 3/8 inch away from the distributor cap tower. (you should do this even if a new plug fixes the problem. You don't want it to reoccour) It should jump a spark. If not, replace the cap and rotor. If it was there but very weak, now replace the coil as well. If so, check for other problems with the cylinder. Vacuum leak, compression etc. There are other ways to check this, but this should be fairly easy to follow.

Ken Styer

|UPDATED|2/12/2004 3:56:36 PM (AZT)|/UPDATED|

Thanks for the easy ground-out tip. I'll try this tonight. Last night, I replaced the O2 sensor(only $13, and it hasn't been changed since I owned the car, doubt if it's been changed in years) and checked the front 4 plugs which seemed black from a rich engine. It seemed to be running better, but I didn't take it on the road yet.

Thanks, if it's not solved or solved by testing for the bad plug/wire, I'll be back!

Thanks for the help peoples. I replaced the O2 sensor which seemed to do the trick. Guess it was running so rich it fouled up the plugs bad enough. No more smoke when I romp on 'er. Now I just need to replace the wires so I know they're not going to be at any fault, never know where they get pinched, so many places. Know of any tips for replacing the wires? I'm thinking about conning someone into doing it for me.
p.s. if you don't see a picture of my car, could someone tell me how to create the signature with a pic the correct way?

Thanks Again !!!