8.1 gas smell on cold start

2008 340 with 8.1 DTS (no IAC ) has a strong gas smell from exhaust on port engine after sitting for a few days. No leaks, no smell in engine compartment and engines start and run well. Replaced spark plugs/wires. No gas in oil
If the engines are started every few days there is no gas smell. If it sits for week or so I get strong gas smell from exhaust on just the initial start after sitting longer then a week. If the computer is setting a too rich condition on cold start up it seems like it would do it on every start up not just after sitting for longer than a week. Not throwing any codes on vessel view.
Any thoughts on things to look at ?
Thanks

Maybe your fuel injectors need to be cleaned. Perhaps there is something preventing one of the from closing completely and gas is leaking by over time. That would be my guess.

My wife and I just bought our 1988 300 Sundancer. Twin 5.7 350 Mercs. We are retired (read:fixed income). Vessel just back into water after having outdrives (Bravo I) serviced, raw water impellers and shift cables replaced, one badly corroded bell housing replaced, two bellows replaced, and all anodes replaced. Whew! $$$$ So I ask the mechanic how much for an oil change/plug change, he says $700-$800. Soooooo, after my wife cleans up the water she threw on my face after I passed out, I decide I can do that myself and probably save $600. I’ve done lots of engine works in the past on cars, and changed a lot of oil, on cars.
How hard will this be? Best way to get old oil out of drip pans? Plugs are pretty self-explanatory, right? I know to bring my swivel pieces and extensions for my ratchet. Any and all suggestions will be greatly appreciated!

Osage said:

2008 340 with 8.1 DTS (no IAC ) has a strong gas smell from exhaust on port engine after sitting for a few days. No leaks, no smell in engine compartment and engines start and run well. Replaced spark plugs/wires. No gas in oil
If the engines are started every few days there is no gas smell. If it sits for week or so I get strong gas smell from exhaust on just the initial start after sitting longer then a week. If the computer is setting a too rich condition on cold start up it seems like it would do it on every start up not just after sitting for longer than a week. Not throwing any codes on vessel view.
Any thoughts on things to look at ?
Thanks

Click to expand...

A fuel pressure test would be a good idea. You most likely have cool fuel 3 modules (CF3).

Have the original CF3 modules ever been replaced? There is a known issue with an internal defect that clogs the regulator and injectors. Google and search are your friends here. Plenty of info about it all over clubsearay.

Espos4 said:

A fuel pressure test would be a good idea. You most likely have cool fuel 3 modules (CF3).

Have the original CF3 modules ever been replaced? There is a known issue with an internal defect that clogs the regulator and injectors. Google and search are your friends here. Plenty of info about it all over clubsearay.

Click to expand...

6

The Cool fuel modules are good. I agree that pressure test is probably next step. Thanks