1997 4.3LX hard starting

[jcoelho]

1997 4.3LX in 1935 Chaparral, 250 hours on engine. Background - boat has been winterized, stored for over a year; 1/2 tank of gas (not sure if gas was treated w/stabil). PO stated he ran a jumper wire bypassing the oil pressure switch. I place throttle in neutral all the way forward once or twice return to high idle notch, turn key, alarm sounds, sometimes I hear and feel the fuel pump running sometimes not. Turn engine over, sometimes it will intiially fire up, rough idle, then stall. Try again and it just doesn't turn over. I suspect faulty fuel pump, bad gas, or both. What do you experts think? Since the season is about over, should I winterize and wait until Spring for a tune up, service, etc., or can I get her tuned up, serviced, winterize and then be ready for the Spring?

What is a good gas treatment/additive? Should I go ahead and fill the tank up, add additive and see if that corrects the problem?

 

[searay3]

Re: 1997 4.3LX hard starting

adding good gas or stabilizers to bad gas just gives you more bad gas. If it's bad it will smell bad. You'll know. Pump out the old, put some fresh in with sta-bil additive. That will store the fresh fuel for next season. However, the carb may be gunked up from the bad fuel. It may have to be soaked and rebuilt. Fix the fuel, get a kit. Pull the top of the carb off, you'll probably wreck the gasket, (thats why the kit), and see whats in there. If it looks ok, suck out the fuel from the bowl and try again. If it works great, but I bet you'll have to go thru the carb anyway. If your not planning to use the boat anymore this year, the carb and tune up will be a good winter project. I would also pull the drive, check the driveline parts and, very important, check the drive oil for water prior to cold weather setting in. Don't forget to drain the block, power steering cooler and circulating pump.

 

[jcoelho]

Re: 1997 4.3LX hard starting - fuel pump?

Re: 1997 4.3LX hard starting - fuel pump?

Actually the gas smells OK now that you mention it. If the fuel pump does't run or runs intermittently when I turn the key, I imagine it's on it's way out...yes?

Can anyone explain why the PO ran a jumper wire to bypass the oil pressure switch. I understand it's a safey issue so the fuel pump will shut down when oil pressure drops - apparently the switch is bad or so he thought. I'm starting to think the fuel pump may actually be the issue.

Is replacing a fuel pump a DIY project? How can I know if the pump is failing for sure? Anyone know the correct fuel pump for a'97 4.3LX? And a oil pressure switch for the same engine?

Thanks in advance for your help.