Volvo Penta GSI -00 ECU failed?

[macdu]

Greetings from Finland.

I've been having hard time this season with my VP 5.7 gsi -00. First symptom was surging idle and power loss and stalling at higher rpm. In addition, there are only two beeps at power up instead of the usual three. Got help with stopping the engine and starting again at first, but it has gotten worse and worse. Yesterday it needed 8 restarts before it ran normally again. Today it did't get better anymore, surging at idle ( 5-800) and stalling when advancing power both warm and cold.

I had a mechanic with VODIA- reader today at the boat and he managed to get a code DTC 41 out of it. According to the EFI- manual it is '' Ignition Control system circuit open''. Probable cause: ECM has seen an open or grounded IC or bypass circuit. According to my mechanic it the ECU that has failed.

Before I want to invest 2000+ dollars on a new ECU I'd like to hear if there could be any other possible cause for the code and the symptoms.

Any suggestions appreciated.

 

[Don S]

Re: Volvo Penta GSI -00 ECU failed?

I seriously doubt the ECU is at fault, and for that guy to read a number and say you need a new ECU is wrong.
Did he do any further testing of the ignition module in the distributor or the connections?

What is the full model number or serial number of your engine.

 

[macdu]

Re: Volvo Penta GSI -00 ECU failed?

No , he did not do any further testing, only the code reading. So, you suggest that I would do some fuel pressure testing and change the rotor, cap and the wires ( plugs are new) before buying a new ECU?

The engine is 5.7 Gsi PEFS ser.nr. 4012012719.

 

[Menard666]

Re: Volvo Penta GSI -00 ECU failed?

I would not purchase a new ECU at this point. I would replace the distributor cap, rotor and wires for sure. If you are not running AC Delco MR43LTS plugs I would replace those as well, gapped to .045". DTC 41 can be thrown as a false code due to engine start/stall.

 

[Don S]

Re: Volvo Penta GSI -00 ECU failed?

Here are some things that needs checked for the DTC 41 before you spend money.

View attachment DTC 41.pdf

That is just for that code, and it's doubful it's the cause of your original problem with the surging and hard start. That sounds more fuel related, faulty sensor, or even engine mechanical.
Compression test, and checking the fuel filter for water would be a couple of the first tests to do.

 

[macdu]

Re: Volvo Penta GSI -00 ECU failed?

Thank you so much for very precise advice. The mechanic that normally does my boat services ( not the same guy that read me the code) promised to see me on monday at the boat, I will pass him these instructions. Actually there is no problem with starting the engine, it starts nicely without any hesitation, only problem is the surging idle and stalling in higher rpm. I sure hope it turns out to be only a bad connection or bad IC module. I will keep you advised.

 

[Don S]

Re: Volvo Penta GSI -00 ECU failed?

Fuel pressures are another thing he needs to check with a surging problem.

 

[macdu]

Re: Volvo Penta GSI -00 ECU failed?

Update. Fuel supply ok, fuel press ok: low 10psi, high 30psi, compression test ok. We did the diagnostic once again, grounds ok, fuel pump relay ok and we ended up having the same result, faulty ECU. Anyway, I decided to order new distributor cap, rotor, wires and IC module and see if that helps any, probably have those early next week.

 

[macdu]

Re: Volvo Penta GSI -00 ECU failed?

Update. Fuel supply ok, fuel press ok: low 10psi, high 30psi, compression test ok. We did the diagnostic once again, grounds ok, fuel pump relay ok and we ended up having the same result, faulty ECU. Anyway, I decided to order new distributor cap, rotor, wires and IC module and see if that helps any, probably have those early next week.

Everything renewed now and with no success. I also bought a new MEFI 3 controller from OBD diagnostics. I bought it as a new unit and programmed as my old one. The new unit runs the engine a lot better, not perfect though. Idle speed now steady 600rpm, only a bit rough. When gradually applying power ( gear in neutral) it hesitates exactly at 2500 rpm, drops by 200rpm and then rapidly accelerates to 3000 rpm. During deceleration down to idle speed the engine runs rough and slightly vibrates. When I went for a ride the engine ran ok, only 200 rpm and 2 knots missing from maximum.

I can now live with the boat, but the rough idle and hesitation really bothers me, I can feel it is not running like it should. Any ideas? Did I buy a bad controller? Wrong program in it?