[vascott99]

Evening all...

After a complete rebuild and new P/C with rings...I was doing my 500 mile break-in service and I was looking at my plugs and noticed that 6, 5, & 4 had a fair amount of carbon build up versus 1, 2, 3 which were fine.

My car ran a bit rich until I could tune the Air fuel which it did take multiple times with varying weather temps and finding out I had a bad fuel relay.

I cleaned them up and I should have taken a photo.

I am using Bosch W4CS and set at .07m


Why one side

[Trak Ratt]

Ignition comes to mind if the spark is weak. Turbo car, right? Could the other bank's intake rubbers be bad? They could be running lean.

[hoophead]

Cam timing - easy enough to check when you readjust the valves at 1K or so.

[RV4Flyer]

Originally Posted by Trak Ratt

Ignition comes to mind if the spark is weak. Turbo car, right? Could the other bank's intake rubbers be bad? They could be running lean.

Carbon fouled plugs are due to a rich (too much air) not lean mixture. I'm not familiar with the engine but by adjusting the mixture you probably fixed the issue. If not it sounds like it may be uneven air/fuel distribution or an intake manifold leak. What is the cylinder layout on the engine? All even on one side and odd on the other?

[vascott99]

Originally Posted by RV4Flyer

Carbon fouled plugs are due to a rich (too much air) not lean mixture. I'm not familiar with the engine but by adjusting the mixture you probably fixed the issue. If not it sounds like it may be uneven air/fuel distribution or an intake manifold leak. What is the cylinder layout on the engine? All even on one side and odd on the other?

I replaced the manifolds and gaskets..and torqued them to speck and rechecked..

Could my spark plug wire set for that side be going bad..

[Dandelion]

Originally Posted by RV4Flyer

Carbon fouled plugs are due to a rich (too much air) not lean mixture.

Uh....rich = too much air? On what planet?

ed

[RV4Flyer]

Originally Posted by Varejao17

Uh....rich = too much air? On what planet?

ed

.
Opps, meant to say fuel not air. Brain moving faster than my fingers. A better description would be a higher fuel to air ratio than optimal. Good catch.

[Trak Ratt]

Originally Posted by RV4Flyer

Carbon fouled plugs are due to a rich (too much air) not lean mixture. I'm not familiar with the engine but by adjusting the mixture you probably fixed the issue. If not it sounds like it may be uneven air/fuel distribution or an intake manifold leak. What is the cylinder layout on the engine? All even on one side and odd on the other?

So very true and that's why I suggested the problem might be on the other side Earlier turbos used CIS with lots of rubber and plastic connectors. Cylinder layout on that engine is like just about all the ather air cooled 911s. Left (facing forward) 1, 2, 3 right 4, 5, 6.

Now if you meant firing order...

Have to admit thought that after careful consideration I'm going with Hoops diagnosis

[vascott99]

Originally Posted by RV4Flyer

Carbon fouled plugs are due to a rich (too much air) not lean mixture. I'm not familiar with the engine but by adjusting the mixture you probably fixed the issue. If not it sounds like it may be uneven air/fuel distribution or an intake manifold leak. What is the cylinder layout on the engine? All even on one side and odd on the other?

Originally Posted by Trak Ratt

So very true and that's why I suggested the problem might be on the other side Earlier turbos used CIS with lots of rubber and plastic connectors. Cylinder layout on that engine is like just about all the ather air cooled 911s. Left (facing forward) 1, 2, 3 right 4, 5, 6.

Now if you meant firing order...

Have to admit thought that after careful consideration I'm going with Hoops diagnosis

Tito and I played with setting the Cams for most of the day and we did get within Elgins recommendation. 2 sets of eye's.. granted mine are not what they use to be. We used the tool I purchased from Stromski that we used to measure.

http://www.stomskiracing.com/product...timing-fixture


Now if Cam timing was the issue wouldn't the car run funny...or as Hoop is implying I could be off a micro hair on the right side and not be noticeable. (other than to the plugs??)

Grrr

I will try to replace the Wires after the new year. Based on some of the PO's work. It looks like they have not been replaced in over 12 years. I have owned the car for about 11 years and have put on over 25K in miles. They do look a bit worn.. or am I just throwing money at the wall?

Thanks again all

[ChaosRogue]

My guess was also a fuel/air ratio issue on that bank. Are you running the CIS, or have you put an EFI setup on it?