I have owned this Duramax in a 5500 bus for 5 years and we've had fuel problems with the engine from the beginning. We've replaced fuel filters, a fuel rail, found a pinched line, and have recently replaced all the injectors with OEM. We still get a 1093 fuel code on our code reader. I drive the bus with a code reader attached so I can erase the trouble code and keep driving. We are searching for any ideas. We live in Alaska and are on vacation in Oregon. The engine will run fine for hours and then will throw a fuel code - sometimes only once, sometimes continually. Sometimes the engine is laboring in heat or uphill, but other times it throws the code going downhill. Always the same 1093 fuel code. Is it possible that the system needs more fuel from a lift pump? Or is there simply a computer update needed to solve the problem?
2005 5500 Fuel code 1093 problem
- Thread starter robertkoenig
- Start date
There are several reasons for this code, including worn injectors returning too much fuel, restrictions on the fuel supply side, pinched lines, dirty tank, dirty filter, etc. If your problem seems to be more prevalent with a low fuel tank, it could be the dirty pickup problem. If same happens with full tank, look elsewhere. I always recommend a lift pump with additional filtration because better fuel filtration is always good, and it eliminates other problems like collapsing fuel lines. Buy a high $$ setup or make your own, just need ~10 lbs pressure. Filter between tank and pump. If all else fails test injectors for excessive returns.
Have you done a bottle test for the FPRV? It being an LLY, it was a common problem, it might be weak and dumping fuel pressure