Fuel System
Some intermittent driveability problems can be attributed to poor fuel quality. If a vehicle is occasionally running rough, stalling, or otherwise performing badly, ask customer about following fuel buying habits.
- Do they always buy from same source? If so, fuel quality problems can usually be discounted.
- Do they buy their fuel from whichever fuel station that is advertising lowest price? If so, check fuel tank for signs of debris, water, or other contamination.