2003 Chaparral Sig 240 5.0Gxi Volvo Penta

[DrD]

I want to install a Floscan 7000 on this boat, and need to know if this engine is a "Closed Loop EFI with CPU Ignition" or an "Open Return EFI with CPU Ignition."

How can I tell?

I have some info on this engine that says its a multiport fuel injection system, but doesn't say beyond that.

Has anyone here installed a Floscan 7000 on a similar boat/engine? Other than the fuel line prefilter, which I have ordered, I don't believe there are any other special parts. Is this right?

Does anyone know if it is acceptable to parallel the tach wiring between the instrument tach and the Flowscan so that both will be seeing the same pulses? Would this overload the tach circuit (pulse driver)?

Part of the Floscan calibration includes selecting the pulse source. The choices that make any sense would either be "from the computer" or manually select for "8 cylinders." Which would be the correct choice?

Thank you for your help.

-Dale-

 

[Maclin]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

I believe "closed loop" means a system that receives feedback from oxygen sensors in the exhaust and adjusts the fuel mix accordingly. I believe most recreational boats, and certainly boats in 2003, do not have oxygen sensors in the exhaust and run in "open loop".

 

[DrD]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

Now that you mentioned that, I'm thinking I did see a oxygen sensor on the port side exhaust manifold. According to my spec sheet, it has multiport fuel injection under the control of an ECM. If an ECM is controlling the injection, wouldn't that need an O2 sensor to make the mix 'just right'?

I'm no mechanic by a long shot, so this reasoning might not be correct.

-Dale-

 

[QC]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

Closed loop systems use absolute manifold pressure (barometric on naturally aspirated) to determine mixture. I don't believe the 2003 has an O2 sensor, but you need to double check.

 

[DrD]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

I checked my operators manual, and what I thought was an O2 sensor is actually just a heat sensor.

-Dale-

 

[Don S]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

You need the same exact FloScan system as a carbed engine will use.
The closed loop just means the excess fuel not used by the injectors doesn't go all the way back to the tank.

 

[bigbrownbuku]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

I believe "closed loop" means a system that receives feedback from oxygen sensors in the exhaust and adjusts the fuel mix accordingly. I believe most recreational boats, and certainly boats in 2003, do not have oxygen sensors in the exhaust and run in "open loop".

its refering only to fuel return. nothing to do with exhaust temp.

modern fuel injected boat engines gain data from a variety of sensors to run the fuel injection, oxygen sensors arent 1 of them. yet.

 

[newport dave]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

In this case "closed loop" refers to the fact that the fuel return from the fuel pressure regulator does not return to the fuel tank, it returns to the fuel water seperator or fuel cell.

"Open loop" would return to the fuel tank and therefore would require a flow sensor be placed in that return line in addition to the sensor in the fuel supply line.

I don't think Volvo or Mercruiser made any open loop systems, but Crusader did.

 

[Maclin]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

I apologize for the wrong info I provided. I was thinking about fuel curve modes and not about measuring actual fuel used by the engine which is what a FloScan is for (doh). Thanks for the corrections guys. I learn something all the time here.

 

[jepps3]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

By the way, for future reference, when talking about EFI systems, closed loop or open loop refers to the feedback capabilities from various sensors that might feed data to the ECM.

While the "Fuel Line" description was used by various posters who replied, the original author was referring to ECM data.

 

[Don S]

Re: 2003 Chaparral Sig 240 5.0Gxi Volvo Penta

It's also a year old. and the OP was wanting to know what kind of fuel system he had in order to install a FloScan 7000