1997 Mercruiser 5.7L EFI stalling problems before vacation

[ccfarm5]

I was following GrantMan's post about his 350 MAG with similar problems, and Don S. suggested I start a new thread. Engine number OK034986, Alpha One drive. Starts fine, and runs strong most of the time. After anchoring in a cove for a while, or pulling tubers, the engine stalls/misfires, and the tach pegs. The temp guage reads 170-175 (fresh water) but the starboard riser is hotter than the port. Not sure if these problems are related at all, but thought I'd better throw that in. I replaced the cap, rotor, and spark plug wires today, and the fuel water separator last week. I did find a small braided ground wire that was a little loose today, but I couldn't tell where it went. I plan to take it out tomorrow to test. I'll take any advice I can get, as we are heading down to Table Rock lake next week for vacation. Thanks for your help,

Chad

 

[Don S]

Re: 1997 Mercruiser 5.7L EFI stalling problems before vacation

EFI and loose ground wires!, depending on what it went to, that could be the problem.
Good clean, TIGHT connections is what makes or breaks and electronic system work. 1 bad ground and everything is a little off.
Having one riser a little hotter than the other at idle is normal. Less water flow.

 

[ccfarm5]

Re: 1997 Mercruiser 5.7L EFI stalling problems before vacation

Update: Back out on the water today, started great, drove at cruising speed for about 20 minutes, and then we anchored in a cove for about an hour. Left to go tubing/test the boat, and sure enough, stalling again, tach pegs again, and now a couple backfires through the throttle body. I'm lost...and sunburned. Jeez, it was hot today!

Thanks again,
Chad

 

[caperman]

Re: 1997 Mercruiser 5.7L EFI stalling problems before vacation

Same thing was wrong with mine,turns out i had bad batterys
hope that helps