| Author |
Message |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2693
Registered: 2-2001
| | Posted on Sunday, May 05, 2002 - 10:04 pm: | |
Greg, I am using the NGK BPR5EVX plugs and it has solved my problem. I was using the 6EVX but they fouled out quickly. |
david handa (Davehanda)
Junior Member
Username: Davehanda
Post Number: 99
Registered: 5-2001
| | Posted on Sunday, May 05, 2002 - 5:50 pm: | |
I think what you are seeing Greg is pretty normal for a carb car. My car (78 308 GTS) has been updated to Bosch blue coils, and the Crane Cams ignition boxes. I also have recently had my carbs rejetted (richer) while on a chassis dyno and exhaust analyzer. It is now running about as "spot on" as you can get. With NGK BPR6EVX platinum plugs, they are STILL a bit black and only light brown around the tips. This car also has fresh factory wires and plug extensions, K&N filter and stock exhaust with no air pump or cats.
It is running around 214 hp at the crank (stock 205). |
Edward Gault (Irfgt)
Intermediate Member
Username: Irfgt
Post Number: 1309
Registered: 2-2001
| | Posted on Sunday, May 05, 2002 - 2:17 pm: | |
A weak coil can cause plug fouling also. An ignition scope would show that up. |
Terry Springer (Tspringer)
New member
Username: Tspringer
Post Number: 49
Registered: 4-2002
| | Posted on Sunday, May 05, 2002 - 1:56 pm: | |
Sounds like rich running, possibly on part throttle. Also, do you drive it fairly hard? Like on an early 911S, the car probably runs a bit rich as normal. This can foul plugs or cause the buildup. One easy solution is to just drive the car harder. Rev it to redline at least once or twice every time you drive it, after it is fully warmed up. This will help prevent carbon buildup.
Early S model 911's were notorious for fouling plugs and it was often simply a matter of American drivers not revving the cars up.
What year and model is your car? I cant wait to get mine! Assuming it passes the pre-purchase, I hope to have it here in 2 weeks or so. |
Greg Rodgers (Joechristmas)
Member
Username: Joechristmas
Post Number: 274
Registered: 3-2001
| | Posted on Sunday, May 05, 2002 - 12:20 pm: | |
Thanks for the info and congrats on your new 308. My cars exhaust is clean and only uses about 1 quart per 3000 miles. The heads were just done at about 10K back. I am thinking it is just when the car idles for too long that it could get the build up. |
Terry Springer (Tspringer)
New member
Username: Tspringer
Post Number: 48
Registered: 4-2002
| | Posted on Sunday, May 05, 2002 - 11:50 am: | |
Does the car smoke at all? Blue smoke by any chance? If the valve guides are worn and the car is burning some oil this would contribute.
My immediate guess would be its running too rich. When you clean off the plugs and replace, how long does it take for the problem to re-occur? Are they fouling so bad the engine is missing? Its normal for a plug to get a bit sooty, thats better than it looking white and chalky!
Terry |
Greg Rodgers (Joechristmas)
Member
Username: Joechristmas
Post Number: 270
Registered: 3-2001
| | Posted on Sunday, May 05, 2002 - 6:17 am: | |
I have noticed that on my 308 carb that some of my plugs get a black soot coating on them. I believe it to be carbon build up but it could be more. I am using a hot plug. Champion N9YC and even after syncing the carbs and running them lean it will still build up. Any thoughts on why it still builds up, oil? Thanks. |