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Buzzer alarm and engine failure on a mercruiser 2001 5.7 EFI engine

mich

New member
"Hope some body can help me on this.
I have a 5.7 EFI 2001 mercruiser on my boat here in Peru south america. There ar no mechanics with and scaner for this type of engine.
There is an alarm or buzzer that bips every 2 seconds intermittent on low RPM (2,000 to 3,000RPM). above the 3,000-3500 RPM the sound gets continue and never stop. Also Im encountering at low RPM (2,000-2500 RPM) an engine failure once on a while. However above 3000 RPM the failure is less.
this failure is like the engine automatically des accelerate for seconds and automatically goes back to normal.
As per the manual I did check disconecting all sensors one by one that could start up the buzzer. oil presure, water temperature and stern oil level. Also clean the stern oil devise to check if the sensor is stick.
Could resolve the alarm sound.
I will apreciate your support and mechanical experience in order to solve both problems.
Mich"
 
"Mich:

Sounds like you have


"Mich:

Sounds like you have the manual so you know there are several inputs beyond the "warning switches" that the computer monitors. The fastest way to find the issue is to get a scan tool.

What you are describing as an "engine failure" is likely the computer restricting the engine RPM based on its inputs ("safe" mode).

If you can't get a scan tool, you are still NOT dead in the water. If you have the factory service manual, you can go thru the descriptions within it and formulate a "most likely" list. Most of the manuals have the nominal sensor values and these can be measured with a digital volt meter. Perserverance will likely reveal the fault."
 
"Thank You Makomark for your a

"Thank You Makomark for your advise. I do not have the service manual. you are correct.Besides the temp, engine oil presure and stern oil level that work properly it seems there are other warning switches the the computer on this engine monitors. hard to know wich one.
Hope some body with a similar failure could be able to give me some tips to solve this issue.
best.
Mich"
 
"You can try downloading this:

"You can try downloading this:

http://www.4shared.com/account/file/115651736/3c087011/Service_Manual_24.html

I think it is the applicable one. You can always enter your serial number at the mercruiser literature request page and see if the part numbers match (manual number is usually 90-xxxx... at the bottom of the page).

If this is the "older" MEFI system, there are a few www posts on how one can build a "code reader". In essence, it is a pigtail connector with a bulb or LED and a couple jumpers.

In the interim, you can read thru the manual and gain more insight on how things work. It may even have the audio horn patterns and what they mean. I can't say as I haven't looked in a while."
 
"Michel.
Just a crapshoot her


"Michel.
Just a crapshoot here but you may have picked up some water in your fuel. Do you have an in line water separator before your fuel pump? It'll be a white canister under a black base. If you have one, unscrew it (put your cigaret out first!), and drain the contents into a clean container. If you have water in there it should sink to the bottom, and be visible. If you do see it, best to check your tank also. I had a similar problem with a former boat that drove me to distraction before I figured it out."
 
Thanks Bob for your suggestion

Thanks Bob for your suggestion. I did check the filter and seems only gasoline on it.
best.
 
Thanks Makomark.
I will revis


Thanks Makomark.
I will revise and advise you on the results. Thanks for your help.
Best
 
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