Which ECM

unbtabl

Seaman
Joined
Jun 3, 2016
Messages
57
I have a 99 Larson 226lxi with the 5.0gi pwtr Volvo Penta. How do I determine which ECM I have?
 

unbtabl

Seaman
Joined
Jun 3, 2016
Messages
57
Thanks. I found it. It’s a 3858338. When I cross reference the number, it states that it’s for the 5.0GIPEFS and 5.0GXi-A. The numbers on my flame arrestor say that my motor is a 5.0GIPWTR which shows should use ecm 3858863. Would this cause issues? I’m still fighting my issue to where the boat won’t accelerate under a load. Revs fine on ears. I’ve replaced the fuel pumps multiple times. It fixed the issue for a bit then burns them up. Replaced everything ignition wise that can be replaced. Ran it off a separate fuel supply. Timing is where it needs to be. Replaced the throttle body. Replaced multiple sensors. As I replace one thing, it fixes the boat long enough to make a few laps, then goes right back to the same issue of just backfiring when I try to give it fuel under load. My last resort is ecm. All of this makes sense if it has the wrong ecm.

 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,234
Doubt it's the ECM. Check fuel pressure under load
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,548
Worked fine prior to 2 summers ago
It works after replacing a sensor then starts it again
I don't see it being the ECM

Should have 29 +/- 2 psi at idle thru WOT
 

unbtabl

Seaman
Joined
Jun 3, 2016
Messages
57
It hasn’t worked since I bought it. It’s worked after replacing fuel pump, then goes back to original issue. Replace a sensor. It works, then goes back to original issue. Replaced the throttle body. Works for a few passes, goes back to original issue. Burns up another fuel pump, replace it. It runs for a few passes, then goes back to the same issue. Yes, that’s the range of the fuel pressure when we check
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,332
Are you replacing the high or low pressure pump?

There may be a vst for the high pressure pump. I've seen those get blocked up with debris more than once
 

unbtabl

Seaman
Joined
Jun 3, 2016
Messages
57
Are you replacing the high or low pressure pump?

There may be a vst for the high pressure pump. I've seen those get blocked up with debris more than once
Both have been replaced. Vst… not trying to sound dumb… is that a small tank?
 

dypcdiver

Lieutenant Junior Grade
Joined
Nov 1, 2005
Messages
1,039
On the 5.0Gi PWTR that I have, the VST (Vapor Separator Tank) with the HP pump is at the rear of the motor.
3 years ago I needed to replace it as it had become blocked and salt water had corroded through to the fuel side and was causing the HP pump to whine.
 
Top