2008 Chaparral 275 SSI 8.1 Volvo Penta GXI-J Soft Alarm Issues

[apisk]

The connection to the new sensor

Does the voltage change when TPS is moved from idle to WOT?

It goes from 4.10 at idle to 4.11 at WOT (I didn't test this with the engine running, just with the sensor plugged in and moving it by hand)

 

[alldodge]

I'm running out of ideas, I don't have Diacom, @tpenfield what do you think?

 

[tpenfield]

I am thinking . . . What is the difference between

TPS ( Thottle Position Sensor)

and

TCP (Throttle Control Position) ???

I'm thinking the TCP is drive by wire, where there is no throttle cable. There must be something else in the overall circuitry that is shorted out and the TCP sensor just completes the circuit.

 

[tpenfield]

I'll go back and look at the data to see if anything else comes to mind.

 

[Donald0039]

I'm running out of ideas, I don't have Diacom, @tpenfield what do you think?

You need a Diacom.

 

[alldodge]

You need a Diacom.

Off topic, I have Techmate, MEFI Burn and MEFI pro

 

[tpenfield]

It looks like TCP only activates when the throttle control is put in gear.
.

 

[tpenfield]

Also, a 14% TPS at idle speed seems way too high. It should be more like 0-5% .

Perhaps the issue is the TPS and not the TCP.

Sorry for the multiple messages . . . I am multi-tasking with this thread and my Evinrude 25 HP, which I've been working on much of the day.

 

[apisk]

I just ran the graphs in Diacom from the recording I sent, and if you put Knock Retard with Soft Warning Output, the Knock Retard jumps exactly at the moments the soft alarms go off, and then go away at the same times too. So far that is the only combo that has been aligned

 

[tpenfield]

Here is another combo . . .

When the TPC are over 50% and the difference between the TCP and the TPS values are 15% or more, the soft warning occurs.

2 examples . . .
.

.

.
I am wondering if the TCP and TPS values should be close if not nearly identical, and when they are not and at a certain amount of control position, it sounds the warning.

 

[tpenfield]

What happens to the reference voltage if you remove the TPS ? Not sure you did that . . .

 

[alldodge]

Post 51

 

[apisk]

What happens to the reference voltage if you remove the TPS ? Not sure you did that . . .

Is the TPS on the throttle body assembly or behind the actual throttle handle? I unplugged every sensor (I believe there were 8 or so) but I don't recall coming across a TPS (I followed this for the sensors https://www.cecilmarineonline.com/p...47720|~0001578-M-28_Ignition/7747720|~22112/y)

 

[apisk]

Here is another combo . . .

When the TPC are over 50% and the difference between the TCP and the TPS values are 15% or more, the soft warning occurs.

2 examples . . .
.
View attachment 384446
.
View attachment 384447
.
I am wondering if the TCP and TPS values should be close if not nearly identical, and when they are not and at a certain amount of control position, it sounds the warning.

Running with this theory, the only way to truly test the new sensor is by running the boat (and not just testing the throttle when off like I did) correct? That way we can see if the TCP % are more aligned to TPS with the new sensor?

 

[apisk]

@tpenfield Just took the boat for a test drive with the new TCP installed, Diacom recording https://drive.google.com/file/d/1h1Gftcos9nDz8v6oi5fk9yqQRmKlsdJ_/view?usp=sharing

The same alarms went off with the same symptoms you called out from the last one. First alarm went off at the 20:12:33 mark

 

[tpenfield]

I was thinking the TPS may be the issue, it starts of higher than it should and ends up lower than it should

 

[apisk]

Do you know if the TPS is on the throttle body? There is a thick plug but not a clear sensor like the other 8 (circled in red)

 

[tpenfield]

Not sure. You should use a parts diagram to locate it. I'm reaching the extent of my V-P knowledge, sorry to say (I'm more of a Mercruiser guy, and they use a different approach to the throttle control) . . .

Maybe the member @muc might be able to offer some suggestions.

 

[apisk]

all the parts diagrams I have found "seem" to show that the sensor is part of the actual throttle body assembly (https://www.volvopentastore.com/Thr...le-Connection/dm/store_id.366--view_id.789172)

I just unplugged this sensor with Diacom hooked up and the voltage didn't change from 4.10. The TCP is the only one that caused it to change

 

[tpenfield]

Another thought that I had was. . . . something going wrong in the throttle control itself. Is there a full wiring diagram for the engine? The one you posted was for the controller itself and somewhat generic.

Also, keep in mind that this effort (so far) is only to get the 2 voltage sources to be at their 5.0 volt spec. Then it is a matter of seeing if the alarm and knock sensor issues are still present.