[tifosi1]

I got a 1980 308, I've been detecting a mis at idle when warm.

I got off the interstate, car is nice and warm, I notice a spotter and a sort of rough idle.

But, car runs great at speed.

I pulled out the back bank of plugs tonight.

The Car has Bosch WR6DP Plugs. What's funny is the white build up of carbon. it's looks thick and you can flack it off with a finger nail. I'd say it's about .010 thick.

The car has 10,000 miles and 10 years on these plugs.

Do you think it is time to change them. GT car parts says not to get the platinum plugs because the regular plugs last just as long.

What do you think?

What do you think about the color of the plugs.
I looked in and saw the piston, they have a nice coat of black wet carbon. No build up. I could see the steal in different spots.

I also found out that the rotors for these cars are history so looks like Nick will be getting some business from one one day.

Thanks
kelly

 

[Magoo]

White Carbon??????

Kelly, Not to be an alarmist but white carbon I have never heard of. Check to be sure you are not getting coolant into the cylinders. Hope not. Just a thought.

 

[Magoo]

Also in regard to what G.T. Car Parts says about the plugs I think they are right. I have used both and the standard NGK No. 5s, a hot plug, have been best for me.

 

[tifosi1]

Update:
I have order the new NGK's.

The front bank does look a little darker than the rear, but not much. I will tell you that I notice alot of heat coming off the back of the rear headers after a good run.

One guy told me today that the reason for the heavy carbon build up is do to the car not being run. In others words you need to drive the hell out of it. I believe the prevouis owner never reved the car over 5,000 RPM.

I hope the new plugs solve the problem.

But one more question, is there a way to richen up the back bank fuel mixture?

Please let me know.
Thanks
kelly

 

[tifosi1]

Magoo, thanks for always being a good freind.

 

['75 308 GT4 (Peter)]

But one more question, is there a way to richen up the back bank fuel mixture?

Please let me know.
Thanks
kelly

Or, it may be that those fuel injectors are dirty and not getting enough fuel through. They all get the same amount of fuel coming out of the fuel distributor, its up to the injectors to deliver it in that specified quantity.

Your hot-headers on that rear bank could mean delayed ignition timing too (instead of all the fuel being burnt in the cylinder at the correct time, its too late and some of it doesn't get burnt. It then travels out with the exhaust and ignites from the hot exhaust tubing).

 

[tifosi1]

Hey read my new post on the Black crap I found in the injection system.

No wonder it has a miss.

 

[Magoo]

Kelly, Thanks for the kind words. I was more than glad to see that my suggestion helped out. My owners manual on my 79 308 GTS calls for 8 1/4 qts. with a filter change. I would think yours should be somewhat the same. To be sure you are correct in your level, Start the car and let it warm up to operating temp. Shut down the engine. Then with in a couple of minutes, before the oil runs out of the oil cooler back into the crankcase, check the oil stick. The level should check just under the MAX. level and not over. The check time is important so be sure to check it within a couple minutes on a warm engine. Magoo