Plugs black. Exhaust tips black. Poor mileage. Some dark smoke
FiTech 400hp. My car #2, (Benz) 350 Crate engine. No codes. All seems ok. Plugs black, exhaust tips black, poor mileage, some dark smoke on acceleration.
Starts easily and runs well. Cruises well, moderately slightly weak acceleration. No problems showing from handheld commander. Older FiTech, just bought the car.
Obviously running rich. What can I do?
What does the AFR, AFR trim and AFR learn say when it is running rich?
Start with the basics. Check plugs. You need to see if they are fuel fouled or oil fouled. Replace them & check remainder of ignition system. Also check O2 sensor. Needs to be in correct position - you can find these details in the FITech manual or online.
FITech will not work if the other system fundamentals are not sound. Good luck.
Plugs are rich mixture foul. How do I check O2 sensor. Here is readout from AFR. I don't know what to do with this?
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We need to see AFR learn. It will be the line below AFR Trim. Plus Coolant Temp must be over 170 before changing anything.
I let the car idle for about 20minutes will not get hotter. I have a hydraulic fan and no electric fan.
AFR 13.7 bounces 14.00
Target AFR 13.64 steady
AFR TRIM% 2.3 bounces -0.8
AFR Learn % -0.8
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I am having same problem on a 1986 SBC 305 with go street 400 HP with the force fuel reservoir. Car runs OK but there are two patches of soot in my garage from the black soot this car produces. Did not do this with the stock rochester qJet.
Motor is a fresh rebuild.
Mileage is sub 13 mpg with a T56 6 speed.