Hi,
I'm in the process of getting a new TPI motor running properly. It is still lean at idle and rich under cruising load.

I pulled the plugs at about 550 miles. All the plugs have a oily residue on the threads and at the base of the threads.

I don't have enough experience to know what to make of this. Would this indicate the oil rings aren't sealing. Or is it a by product of the overrich condition and is old fuel.

The electrodes don't look to good either. Black on one side and white on the other. On the white side there is some buildup of some sort.

Any ideas?

Thanks,
Jim

 

Don't sweat it until you get about 1,500 good miles on the engine/rings. Just keep changing plugs.

As for the fuel system issues, about all I can advise is to recheck the TPS and fuel pressure. Are you running a MAF or speed/density ECM? What modifications, if any?

 

Vader,
Thanks for the tip.

Engine is modified. Should make over 400hp if i ever get it running right.

383ci long block with fairly extensive porting (professionally built).
Accel superram plenum, runners, base and 58mm TB.
1 3/4" headers.
Ed Wright chip which needs some additional tweaking.

TPS is right on the money, checked with a scan tool.

It's a MAF car which may eventually prove to be a limitation. But for right now I like the idea of the adaptability of the MAF setup.

Fuel pressure is set at 50lbs. I will try going lower and see how that affects things but I think the chip needs some work.