8.1 volvo penta ECU help

[Pcmcguire]

Need some help. Put a new 8.1 engine in my boat. We have replaced about every sensor and it still does not run right. We are thinking they sent us a 420hp engine instead of a 375hp. I know its a long shot but does anyone have a 8.1 420hp ECU I could borrow to throw on this engine to test it? Located in NC.

Thanks
Pat

[km1125]

What does it do that makes it "not run right"?

Did you replace sensors because they were faulty or the ECU was giving codes, or were you just throwing parts at it? Many ECUs use the exact same sensors.

[Pcmcguire]

We had to replace the engine. It runs fine until it warms up then goes lean. Diagnostics shows all the sensors are working. Both me and my mechanic are baffled at this point.

[Viper]

Source of the post ....We are thinking they sent us a 420hp engine instead of a 375hp.....

Who is "they"? A Volvo dealer? Was this ordered through Volvo using the part number for a long block based on your engine serial number, and you simply swapped all the bolt-on hardware? If you did it this way, you'll have the correct block.

Why was the engine replaced? Why did it fail? If it failed due to some outside influence and you didn't correct that prior to installing the new engine, this one might not run right and fail shortly too.

[Pcmcguire]

When I purchased the boat one engine was not running. Engines had been replaced during the life of the boat by Volvo at some point. The hull ID states the boat came with the lower HP 380hp engines. I ordered an engine based off of this information. Engine is installed but leans out once it is warmed up. Pulled the freeze plug out of the back of the old engine and the numbers off the cam are 89129355 which I am told is the 420hp camshaft. So what I am trying to do is see if we have an engine/ecu mismatch. Oh and by the way the machine shop I ordered the engine from says there is a possibility they may have give me a 420hp engine by mistake, may have........ yeah I know no comments necessary. So right now am at a loss as to how to determine for sure the ecm and motor are compatible without first tearing down the engine and removing the cam and then try both ecms.

[bud37]

Welcome to the forum.
I agree with you, the engine parameters may be some different based on the TB size/ airflow etc. if applicable .

Now seems to me there are a few people that can fool with these ecu' s , one being in California if I remember right. I was having issues with the ecu's on our old boat and had him look at run recordings. For the life of me I can't remember the business name, sorry.

Try volvo and find out the ecu # that was applied to those engines, should be in their parts somewhere.....from that you can check what you have now.

[km1125]

How are you determining "Engine is installed but leans out once it is warmed up. "

Does it do this at all loads or just up at cruising or WOT?

And I agree with bud37 that you can get the ECU reprogrammed if that's indeed the issue. Can you tell on the scan tool what image is installed on both this ECU and the other engine?