SB

BUP, does the Volvo tbi injectors get fired twice as much as a batch fire multiport ?
They do in the TBI vehicles. (Sorry to bring in the vehicles so much)

I know most multiport batch systems end up having idle Ms of around 2Ms or so. 2Ms to 2.5Ms seems quite normal all averaged in together.

nunnink23

The plugs are a darker black, which Would make me think rich, but they could just be like that from all the fuel pouring. They certainly aren't shot from that. I have new plugs for once this is resolved.

I still just can't imagine how it would be rich, given the nature of this problem. It sounds like a lean bog, and it definitely is a lean cold start issue. The plugs are bone dry when cranking cold. Absolutely bone dry. They don't even smell like fuel.

BUP- we tested all the things you mentioned in those posts though, so I'm just lost on where to go next. Again I have a dealer who can take the boat in later in the week or early next week, but I really don't think they will be able to resolve this. They don't even have a scan tool on site. None of my local dealers are even volvo penta dealers.

I would prefer to put this to bed myself, especially since the expense is really starting to add up.

BUP

For app as mentioned and I said this. I found pics of your injectors it is stamped Rochester part number 25170310 ACR and if I recall GM is 5176 not 100 % on that one GM 5176. It is a Black & yellow markings on the injector and yes I seen the color markings as well.

You have to watch buying sensors, ignition especially modules and electrical marine parts online. Even fuel injectors are being knocked off and claiming to be OEM. Many knock off cheap junk on the net and the marine end has its fair share. The ign modules are the worst. I see this once a week. Just saying.

nunnink23

Could my ignition module be causing this? I have a sierra one in there now. My original one still works too, or has the same result at least. I just thought the ignition module is working if it's communicating reference signals. Isn't that the extent of what they do, and the ecm takes it from there?

BUP

TBI fire one injector on one ref hi signal and the second injector on the next ref hi signal. The injectors only fire one time per complete firing cycle of the engine

BUP

U can always test your ign module - I remember you said you have the service manual it should be in there how to. You can double check your timing - I know you put it into base timing mode to set the timing correct ? if all of that is stable (timing) and you have you spark plug wires installed correctly ( the correct firing order) I think your module is fine. I am on a lunch break and have to get back at it myself. If your manual is Clymer or seloc they really are not that good hopefully your have the Volvo service manual box set. The ign module testing is in there. If you do not have it, I can post all of tonight

nunnink23

I do have the manual so I will follow the procedure. I double checked both cam timing and ignition timing on Sunday. Both checked out fine. Stupid timing cover wouldn't go back on correctly without dropping the front of the pan. I'll give it one more shot with a new cover before I yank the engine again.

Any thoughts on the ECM reflash?

BUP

Ok heading back out so what to ask before anything else.

You have MEFI IV conversion - who did this for U - where did the conversion come from Volvo ? If not who ? Do you have the instruction sheet that is given for the install ?

U keep saying reflash who flashed this to begin with ? This should have been a packaged set that is a straight conversion from the OEM and how Volvo wanted it installed especially with the IAT sensor . I have to get back it myself. I am lost about this reflash or flashed ECM ?

Please tell me what manual you are using is it Volvo penta for the EF models ? Not an aftermarket manual.

nunnink23

I am using the factory volvo EF manual. And I don't have record of who did it. It was done by the previous owner, but I am pretty confident it was done right. It ran beautiful all last year until I pulled the engine. And I know its mechanically sound. And it has good spark. The only fuel system component I touched Is the TBI. It has the right pressure.... Fuels good... Pump is flowing.... Idk.

Mefi burn said Its extremely unlikely that my ecm needs a flash. They already bench tested it and it had the locked volvo tune on it.

I'm sending them my data file recording from the Rinda tool tonight.

nunnink23

Oh, btw I have a GM master tech at my Marina this year. He looked at the engine with me on Sunday and he is just as lost as I am. He told me to drag test the j1 and j2 connectors. But I forgot the pin size drag tester he mentioned.

SB - any idea what type of carb will fit this, and how I can retain the computer for gauges and all that? It's a last resort still... But I guess I need to start researching it now just in case. Fuel pump and all that should still work? I'm guessing these engines have pretty well documented jet size requirements.