Spark plugs after a complete rebuild

[vascott01]

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

[Lapkritis]

Carbs out of balance? Check adjustment to make sure the butterflies open simultaneously.

[vascott01]

Originally Posted by Lapkritis

Carbs out of balance? Check adjustment to make sure the butterflies open simultaneously.

No Carbs...


Anyone??

[Tippy]

Originally Posted by vascott01

No Carbs...


Anyone??

You still haven't mentioned what engine, induction system, nor ignition, and you're asking for help? :/

[vascott01]

My apologies

1979 930 - engine 83 ROW/Canada based on the stamp on the case,
type 930/66
CIS fuel injection

Only Mod was 930 sport grind on the cams by Elgin Cams

[turbo owner]

plug wires?

[vascott01]

The car drives well.. I might consider new wires. They were one of the few things I did not replace...

[mytoy]

You sure that your plugs are set at .07mm gap? That seems extremely tight, like almost closed. 7mm might be better.

[vascott01]

Originally Posted by mytoy

You sure that your plugs are set at .07mm gap? That seems extremely tight, like almost closed. 7mm might be better.

my mistake...bad eyes..it is actual .7milimeters based on my cheap gap tool.

[mytoy]

Well then your eyes must bee really bad as the gap should be 7mm or 27 thousands of an inch.

I usually gap the plugs at 30 to 32 thousands for n/a but if your a turbo then 27 thousands or 7 mm would be right.

[Tippy]

Originally Posted by vascott01

My apologies

1979 930 - engine 83 ROW/Canada based on the stamp on the case,
type 930/66
CIS fuel injection

Only Mod was 930 sport grind on the cams by Elgin Cams

Try the 930/Supercgarging forum, lots of knowledgeable 930/CIS guys there.

79 is super special!

[Steve@Rennsport]

Plug wires for sure if you never replaced them; they really suffer on a Turbo.

If you didn't send the injectors out for checking and cleaning, thats what you do right now.

[porterdog]

Originally Posted by mytoy

Well then your eyes must bee really bad as the gap should be 7mm or 27 thousands of an inch.

I usually gap the plugs at 30 to 32 thousands for n/a but if your a turbo then 27 thousands or 7 mm would be right.

Back to school with you

1mm = ~.40", so 7mm would be ~.28" or over a quarter inch.

[crg53]

Originally Posted by mytoy

Well then your eyes must bee really bad as the gap should be 7mm or 27 thousands of an inch.

I usually gap the plugs at 30 to 32 thousands for n/a but if your a turbo then 27 thousands or 7 mm would be right.

No offence, but your math must be really bad. 7 mm = 0.275591 inch, not 0.027 inch.

[mreid]

Another possibility is cam timing on that bank. How does the engine run?

[mytoy]

You are correct my math was terrible. Back to school for me and detention already.
.7mm should be the correct gap. Sorry.

[vascott01]

Originally Posted by mreid

Another possibility is cam timing on that bank. How does the engine run?

I used Stromski's cam timing tool and had a buddy asist to ensure the second set of eyes. Unless it is now off by a micro hair. I am not sure...

engine runs great when it is warmed up. I am having an issue with the AAR. 1700 rpms on start up and after about 10 mins it drops down to 1250. Then after driving it for awhile it drops to 1000rpms.

Which I did remove and then added back as it seemed to work better after cleaning it up and checking connections. I do have a buddies that I will put in to see if that is causing the issue for the next 500 miles...

Thanks again all for your recommendations..

Cheers