2 weeks ago, I postet about my 348, that could pull propperly under 3000rpms, like its had a stumble or something.. Today the car dident want to pull clean under 5000rpms, and had some stumbles all the way up, finally the 5-8 slow down came on...Time for some action.. Drove back to the garage, pulled the plugs on 5-8 bank. 5 -OK 6 -OK 7 -OK 8 ---NOT OK! (see pic) 1,2,3,4 all fine too Since all stores are closed here, ill have to wait untill tomorrow to find some new plugs, This MUST be why I have a stuble...I has to rev high, so I can create a spark on that plug.. Noe i only hope that the pice was blow out with exhaust, or burned away on the plug. Image Unavailable, Please Login Image Unavailable, Please Login
You'd think...except that losing 1/8th of the power of your engine usually isn't enough to feel inside the driver's cockpit. But you obviously have to correct *that* bad spark plug before you can figure out if something else is also wrong (which is possible). You are on the right path, though!
well is not that feel like i have lost 50HP or so..the engine just stumblesm and only ran smooth in the high revs....Which i think is due to the plug only being able tp create spark at those high rpms.. The overheat cat on bank 5-8, must all the un burned fuel from spark 8. cant wait to try it with fresh plugs... Since I have only had the car for 4 weeks, and the problem startet when I was really getting to know the car, it will be like getting a new car again when she runs smooth. I hope...
Ill try and find some NGK DR8EIX, found that Aprilla motorcycles use them, so think I have a chance..
What is involved in changing spark plugs? Any special tools other than deep metric sockets? Do you simply pry the wire and boot off the plug and then unscrew it? It seems like you could get to all 8 pretty easily. I might add this to my todo list.
Great find mate. That worn/stuffed plug was definitley the engine 'miss' you had. A new set of NGK plugs and you will be running 100% again. Spark plugs actually wear out and should be changed every 40,000km or every major service for a Ferrari. You can also get platinum spark plugs that last around 100,000km and apparently have a 'stronger' spark/more power. The only difference I see is that a normal NGK spark plug costs AU$6 each and a platinum NGK spark plug costs AU$30 each!!! Your choice on what you want to buy for your car, but I would get stocko NGK plugs. Platinum plugs......my friend here owns a big HP Nissan R33TT Skyline. He wanted to see if NGK platinum spark plugs really gave you stronger spark, meaning more power, so he dyno tested his R33 and got some excellent results. The NGK platinum plugs made an extra 14HP over stock plugs on the dyno!! I forget what the before and after HP numbers his car had were sorry. But they didnt believe it, so they ramped it up again and it still made around 14HP!! How goods that? He was very happy, but you would want to be spending AU$180 on 6 spark plugs! I dont really want to spend AU$240 on 8 spark plugs for my 348 and not have the same performance increase. Not sure you would make the same HP increase. You never know............but I will stick to buying the stocko NGK plugs. If I ever decided to get some platinum plugs, then I will do a before/after dyno run for the brotherhood and post the results.
Very easy job mate. You got it all correct. All you need is a spark plug socket/rachet/extension ect.....
Got some NGK Platinum in today... I got a V8 again... Pulles even ans smooth all the way from 2000rpm to rev limit in 5th, a hole new car to me. Im very pleased and happy now.
mission completet. Took it out on some back roads to celebratate, with the Capristo has microphone for my V8 singing again, it was really great in this lovly summer weather!
Just curious, if your spark plugs are worn out, when was the last service done? You may want to check some of the other service items before they fail also.
Late 2005.(nov I think) I know what you mean. Talked to mechanic who said that if is been a garage queen, that has been startet, back out the garge, and then turned off, all the time, it will stress the plugs more... My car did excatly that. Last owner did 1500km in 2 years.... Other than that it could simply be a faulty plug, as the other 7 seem fine!
True. Other possibilities that will cause a plug to burn like that are: 1. Too low of a heat rating for the application. (unlikely since the other plugs look okay.) 2. Ignition timing too far advanced. (unlikely again) 3. Too lean air-fuel mixture. (Possible. The injector for this cylinder may have a problem causing the mixture to be lean. Make sure all connections are good. May not be a bad idea to pull the injector and have it bench tested.)
Dude, I thought al your plugs looked a bit charred. Maybe you better check the fuel mixture at higher rpms. You could be running lean/hot. Congrats on the new engine. These cars a alot more fun with all cylinders firing, eh?
Sounds like a goodes idea, ill watch the condition of that plug over the next miles... I still think its was just a bad plug as the car seems to rev quite smooth and nice at all rpms... But a A/F control is always good...
That's a good idea to carefully watch that one plug/injector over the next 100 miles. Could easily be a bad injector (or electrical connection to the injector).
