Hello.
I have a Regal Cruiser with the MCM 5.0 EFI V8 Engine.
There appears to be a fuel issue and I would like your thoughts and opinions.
Main symptoms: Boat accelerates to 30mph, then 25, then 20 until eventually it won't go over 10mph.
The work done on the engine so far is: service (including distributor cap and rotor arm), new fuel pump, new MAP sensor, new batteries and few other things.
First, when the fuel pump was changed (cool fuel) they didn't put the vacuum line back on the fuel pressure regulator. I did some reading on this and it appears that this line simply connects to the flame arrestor so I am not sure if this operates via vacuum to operate or just for safety in case the regulator fails. I cannot put the vacuum line back as I don't have the means to lift the engine slightly to access the cool fuel box when the regulator is located. The line just connects to the flame arrestor and is disconnected and dangling on the other end.
I did some basic diagnosing and this is what I have found; when I rev the engine from idle to say.. 2000RPM or so with a quick throttle stab, the injectors dumps so much fuel to the point where the engine nearly dies, it seems to be flooding it. I can physically see it turn from a fine mist to a waterfall almost. It does look like a clean injection however, the injectors seem to have a healthy spray pattern and doesn't appear to drip. The engine doesn't always die, it slightly coughs but eventually regains itself.
Another issue is when I put rev the engine to a fixed RPM the engine creeps up in RPM. To make it clear, if I rev to 1500RPM and leave the throttle there, the engine will go to 1500RPM, 2 seconds later it will rise to 1700RPM and then usually another jump to 1900RPM. During this, I can see the injector spray change every time the RPM creeps up. It becomes a spitty/pulsing type injection that becomes more finer and less spitty/pulsing and more consistent as the RPM creeps up incrementally. I notice this when driving the boat as well.
I want to do a fuel pressure test but apparently I need a special T piece to connect a gauge to but where I am in the UK, sourcing these parts are terribly difficult. I'm lucky enough to be able to just get the service parts let alone special diagnostic tools and fittings.
Any thoughts?
I have a Regal Cruiser with the MCM 5.0 EFI V8 Engine.
There appears to be a fuel issue and I would like your thoughts and opinions.
Main symptoms: Boat accelerates to 30mph, then 25, then 20 until eventually it won't go over 10mph.
The work done on the engine so far is: service (including distributor cap and rotor arm), new fuel pump, new MAP sensor, new batteries and few other things.
First, when the fuel pump was changed (cool fuel) they didn't put the vacuum line back on the fuel pressure regulator. I did some reading on this and it appears that this line simply connects to the flame arrestor so I am not sure if this operates via vacuum to operate or just for safety in case the regulator fails. I cannot put the vacuum line back as I don't have the means to lift the engine slightly to access the cool fuel box when the regulator is located. The line just connects to the flame arrestor and is disconnected and dangling on the other end.
I did some basic diagnosing and this is what I have found; when I rev the engine from idle to say.. 2000RPM or so with a quick throttle stab, the injectors dumps so much fuel to the point where the engine nearly dies, it seems to be flooding it. I can physically see it turn from a fine mist to a waterfall almost. It does look like a clean injection however, the injectors seem to have a healthy spray pattern and doesn't appear to drip. The engine doesn't always die, it slightly coughs but eventually regains itself.
Another issue is when I put rev the engine to a fixed RPM the engine creeps up in RPM. To make it clear, if I rev to 1500RPM and leave the throttle there, the engine will go to 1500RPM, 2 seconds later it will rise to 1700RPM and then usually another jump to 1900RPM. During this, I can see the injector spray change every time the RPM creeps up. It becomes a spitty/pulsing type injection that becomes more finer and less spitty/pulsing and more consistent as the RPM creeps up incrementally. I notice this when driving the boat as well.
I want to do a fuel pressure test but apparently I need a special T piece to connect a gauge to but where I am in the UK, sourcing these parts are terribly difficult. I'm lucky enough to be able to just get the service parts let alone special diagnostic tools and fittings.
Any thoughts?
