Logo
FULL SITE MENU

2001 5.7 efi

D

Dslbrnr

New member
Having an issue with my 2001 5.7 EFI. Fires up and idles fine but when trying to power up seems to have no power beyond 2000 rpm. Engine seems very noisey (pinging??) as well above 2000 rpm. Replaced fuel pump and coil at this point. Taking it from Marina to boat launch leaned up against wiring harness to ECM and it stalled. Fired back up fine. Just wondering if a poor connection to the ECM would cause that problem? and if so, any tips on getting better contact at ECM plug. There are no codes showing.
 
Ayuh,.... No power, 'n detonation are usually signs of a lack of Fuel,.....

Was there any crap in the old fuel filter,..??
 
My 5.7FI also drove me crazy last year with the same problem. After checking fuel filter and fuel screen try n AUX Fuel tank and see what happens.It could be just a bad tank of gas. Does the alarm go off?
 
Fuel filter seemed good when I changed it out (no crap in old one). Different filter though, Mercruiser to Sierra. Don't suspect bad fuel either. I have twin drives and the other motor runs fine. Don't have any alarms and no codes showing...just sounds like pinging and struggling beyond 2000 rpm. BIGALF, where is the screen?? I will check that. Very frustrating. I am in a very remote area and do not have access to a mechanic. Bondo...I agree, seems like a fuel issue. Just found it odd that boat stalled when I moved wiring harness. Maybe just coincidence, not sure a poor connection would cause the same issues. Just grasping right now.
 
Dslbrnr said:
Fuel filter seemed good when I changed it out (no crap in old one). Different filter though, Mercruiser to Sierra. Don't suspect bad fuel either. I have twin drives and the other motor runs fine. Don't have any alarms and no codes showing...just sounds like pinging and struggling beyond 2000 rpm. BIGALF, where is the screen?? I will check that. Very frustrating. I am in a very remote area and do not have access to a mechanic. Bondo...I agree, seems like a fuel issue. Just found it odd that boat stalled when I moved wiring harness. Maybe just coincidence, not sure a poor connection would cause the same issues. Just grasping right now.
Click to expand...

Ayuh,.... Did ya inspect the wirin' ya moved, 'n the wirin' ends around that area,..??

It could well be something like that,....

The 'puter controlled motors are tough, without 'puter diagnostics,......

All ya can do in go over every inch of wirin', 'n Hope ya find an issue,....
Then there's the fuel pressure to the injectors, 'n checkin' the ignition hard parts,...

Have ya peeked under the distributor cap,..??
Could be a crack, or corrosion, or carbon trackin',....
 
I have a throttle body fuel injectionon my engine and the screen is just before the fuel line goes into the throttle body
 
One thing I haven't done yet is check the distributor cap and wires. As far as diagnostics I have a Diacom diagnostics system that shows no codes and good fuel pressure. BIGALF, what solved your issue? I will check screen to throttle body next. Thanks guys for your input.
 
money, money , money!!! I can't say what the fix was that corrected my problem but after MAP Sensor (controls fuel flow), Fuel screen and spark plug wires were replaced the engine now runs fine. I would fix the cheapest first. The Fuel screen and spark plugs and plug wires should be an easy fix to start with. Let us now what you find that did the fix.
 
Last edited:
Got a call today from my mechanic who after many hours trying to find why the alarm would go off and engine drop in speed he finally found a small nick in a wire and when it touched the engine it would spark the set alarm and drop RPM. Tuesday will be the test on the water under load to see if this was the problem that was driving me and him crazy for 3months.
Maybe all the stuff I did before was a waste of money.
 
Last edited:
There was a wire that connect to the altinator that appears to have started all the problems.When it would hit the engine the computer would go off and the engine would drop RPMs. A small problem took a goodguy to finally find it.The wire had 2 smal lnicks showing bare wire and when the wire would move it would case a spark and then the alarm would go off and the egine woud drop RPM. That andgetting lte water ut of he fueltank solvd m proble. Hope this helps all.
 
Last edited:
Back
Top